diff --git a/searx/engines/archlinux.py b/searx/engines/archlinux.py
index cad06f8c6..245bc50b2 100644
--- a/searx/engines/archlinux.py
+++ b/searx/engines/archlinux.py
@@ -26,7 +26,7 @@ xpath_results = '//ul[@class="mw-search-results"]/li'
 xpath_link = './/div[@class="mw-search-result-heading"]/a'
 
 
-# cut 'en' from 'en_US', 'de' from 'de_CH', and so on
+# cut 'en' from 'en-US', 'de' from 'de-CH', and so on
 def locale_to_lang_code(locale):
     if locale.find('-') >= 0:
         locale = locale.split('-')[0]
@@ -36,7 +36,7 @@ def locale_to_lang_code(locale):
 # wikis for some languages were moved off from the main site, we need to make
 # requests to correct URLs to be able to get results in those languages
 lang_urls = {
-    'all': {
+    'en': {
         'base': 'https://wiki.archlinux.org',
         'search': '/index.php?title=Special:Search&offset={offset}&{query}'
     },
@@ -67,7 +67,7 @@ lang_urls = {
 def get_lang_urls(language):
     if language in lang_urls:
         return lang_urls[language]
-    return lang_urls['all']
+    return lang_urls['en']
 
 
 # Language names to build search requests for
diff --git a/searx/engines/bing.py b/searx/engines/bing.py
index 052d567ea..2e58d0293 100644
--- a/searx/engines/bing.py
+++ b/searx/engines/bing.py
@@ -32,10 +32,7 @@ search_string = 'search?{query}&first={offset}'
 def request(query, params):
     offset = (params['pageno'] - 1) * 10 + 1
 
-    if params['language'] != 'all':
-        lang = params['language'].split('-')[0].upper()
-    else:
-        lang = 'EN'
+    lang = params['language'].split('-')[0].upper()
 
     query = u'language:{} {}'.format(lang, query.decode('utf-8')).encode('utf-8')
 
diff --git a/searx/engines/bing_news.py b/searx/engines/bing_news.py
index b999b2a39..c609a1949 100644
--- a/searx/engines/bing_news.py
+++ b/searx/engines/bing_news.py
@@ -71,10 +71,7 @@ def request(query, params):
 
     offset = (params['pageno'] - 1) * 10 + 1
 
-    if params['language'] == 'all':
-        language = 'en-US'
-    else:
-        language = params['language']
+    language = params['language']
 
     params['url'] = _get_url(query, language, offset, params['time_range'])
 
diff --git a/searx/engines/dailymotion.py b/searx/engines/dailymotion.py
index fad7e596c..cfa76796d 100644
--- a/searx/engines/dailymotion.py
+++ b/searx/engines/dailymotion.py
@@ -32,10 +32,7 @@ supported_languages_url = 'https://api.dailymotion.com/languages'
 
 # do search-request
 def request(query, params):
-    if params['language'] == 'all':
-        locale = 'en-US'
-    else:
-        locale = params['language']
+    locale = params['language']
 
     params['url'] = search_url.format(
         query=urlencode({'search': query, 'localization': locale}),
diff --git a/searx/engines/duckduckgo.py b/searx/engines/duckduckgo.py
index 921e29f8b..6f8797fed 100644
--- a/searx/engines/duckduckgo.py
+++ b/searx/engines/duckduckgo.py
@@ -44,9 +44,7 @@ content_xpath = './/a[@class="result__snippet"]'
 # match query's language to a region code that duckduckgo will accept
 def get_region_code(lang, lang_list=None):
     # custom fixes for languages
-    if lang == 'all':
-        region_code = None
-    elif lang[:2] == 'ja':
+    if lang[:2] == 'ja':
         region_code = 'jp-jp'
     elif lang[:2] == 'sl':
         region_code = 'sl-sl'
@@ -82,12 +80,8 @@ def request(query, params):
     offset = (params['pageno'] - 1) * 30
 
     region_code = get_region_code(params['language'])
-    if region_code:
-        params['url'] = url.format(
-            query=urlencode({'q': query, 'kl': region_code}), offset=offset, dc_param=offset)
-    else:
-        params['url'] = url.format(
-            query=urlencode({'q': query}), offset=offset, dc_param=offset)
+    params['url'] = url.format(
+        query=urlencode({'q': query, 'kl': region_code}), offset=offset, dc_param=offset)
 
     if params['time_range'] in time_range_dict:
         params['url'] += time_range_url.format(range=time_range_dict[params['time_range']])
diff --git a/searx/engines/duckduckgo_images.py b/searx/engines/duckduckgo_images.py
index dbd78b074..7b0e72694 100644
--- a/searx/engines/duckduckgo_images.py
+++ b/searx/engines/duckduckgo_images.py
@@ -53,12 +53,8 @@ def request(query, params):
     safesearch = params['safesearch'] - 1
 
     region_code = get_region_code(params['language'], lang_list=supported_languages)
-    if region_code:
-        params['url'] = images_url.format(
-            query=urlencode({'q': query, 'l': region_code}), offset=offset, safesearch=safesearch, vqd=vqd)
-    else:
-        params['url'] = images_url.format(
-            query=urlencode({'q': query}), offset=offset, safesearch=safesearch, vqd=vqd)
+    params['url'] = images_url.format(
+        query=urlencode({'q': query, 'l': region_code}), offset=offset, safesearch=safesearch, vqd=vqd)
 
     return params
 
diff --git a/searx/engines/faroo.py b/searx/engines/faroo.py
index 7ce3a6ce8..4e8b56743 100644
--- a/searx/engines/faroo.py
+++ b/searx/engines/faroo.py
@@ -40,10 +40,7 @@ def request(query, params):
     offset = (params['pageno'] - 1) * number_of_results + 1
     categorie = search_category.get(params['category'], 'web')
 
-    if params['language'] == 'all':
-        language = 'en'
-    else:
-        language = params['language'].split('_')[0]
+    language = params['language'].split('-')[0]
 
     # if language is not supported, put it in english
     if language != 'en' and\
diff --git a/searx/engines/gigablast.py b/searx/engines/gigablast.py
index 2bdc97fd1..99791a423 100644
--- a/searx/engines/gigablast.py
+++ b/searx/engines/gigablast.py
@@ -49,12 +49,9 @@ supported_languages_url = 'https://gigablast.com/search?&rxikd=1'
 def request(query, params):
     offset = (params['pageno'] - 1) * number_of_results
 
-    if params['language'] == 'all':
-        language = 'xx'
-    else:
-        language = params['language'].replace('-', '_').lower()
-        if language.split('-')[0] != 'zh':
-            language = language.split('-')[0]
+    language = params['language'].replace('-', '_').lower()
+    if language.split('-')[0] != 'zh':
+        language = language.split('-')[0]
 
     if params['safesearch'] >= 1:
         safesearch = 1
diff --git a/searx/engines/google.py b/searx/engines/google.py
index 363b7fb6f..47a560aac 100644
--- a/searx/engines/google.py
+++ b/searx/engines/google.py
@@ -165,7 +165,8 @@ def extract_text_from_dom(result, xpath):
 def request(query, params):
     offset = (params['pageno'] - 1) * 10
 
-    if params['language'] == 'all':
+    # temporary fix until a way of supporting en-US is found
+    if params['language'] == 'en-US':
         params['language'] = 'en-GB'
 
     if params['language'][:2] == 'jv':
diff --git a/searx/engines/google_news.py b/searx/engines/google_news.py
index 8881d0dad..8b8e7175d 100644
--- a/searx/engines/google_news.py
+++ b/searx/engines/google_news.py
@@ -50,9 +50,8 @@ def request(query, params):
     params['url'] = search_url.format(query=urlencode({'q': query}),
                                       search_options=urlencode(search_options))
 
-    if params['language'] != 'all':
-        language_array = params['language'].lower().split('-')
-        params['url'] += '&lr=lang_' + language_array[0]
+    language_array = params['language'].lower().split('-')
+    params['url'] += '&lr=lang_' + language_array[0]
 
     return params
 
diff --git a/searx/engines/mediawiki.py b/searx/engines/mediawiki.py
index 0607ac93b..c7b05ffcd 100644
--- a/searx/engines/mediawiki.py
+++ b/searx/engines/mediawiki.py
@@ -45,10 +45,7 @@ def request(query, params):
 
     format_strings = list(Formatter().parse(base_url))
 
-    if params['language'] == 'all':
-        language = 'en'
-    else:
-        language = params['language'].split('-')[0]
+    language = params['language'].split('-')[0]
 
     # format_string [('https://', 'language', '', None), ('.wikipedia.org/', None, None, None)]
     if any(x[1] == 'language' for x in format_strings):
diff --git a/searx/engines/photon.py b/searx/engines/photon.py
index 15236f680..240841954 100644
--- a/searx/engines/photon.py
+++ b/searx/engines/photon.py
@@ -35,10 +35,9 @@ def request(query, params):
         search_string.format(query=urlencode({'q': query}),
                              limit=number_of_results)
 
-    if params['language'] != 'all':
-        language = params['language'].split('_')[0]
-        if language in supported_languages:
-            params['url'] = params['url'] + "&lang=" + language
+    language = params['language'].split('-')[0]
+    if language in supported_languages:
+        params['url'] = params['url'] + "&lang=" + language
 
     # using searx User-Agent
     params['headers']['User-Agent'] = searx_useragent()
diff --git a/searx/engines/qwant.py b/searx/engines/qwant.py
index 3d266e228..408c2b3de 100644
--- a/searx/engines/qwant.py
+++ b/searx/engines/qwant.py
@@ -44,18 +44,17 @@ def request(query, params):
                                    query=urlencode({'q': query}),
                                    offset=offset)
 
-    # add language tag if specified
-    if params['language'] != 'all':
-        if params['language'] == 'no' or params['language'].startswith('no-'):
-            params['language'] = params['language'].replace('no', 'nb', 1)
-        if params['language'].find('-') < 0:
-            # tries to get a country code from language
-            for lang in supported_languages:
-                lc = lang.split('-')
-                if params['language'] == lc[0]:
-                    params['language'] = lang
-                    break
-        params['url'] += '&locale=' + params['language'].replace('-', '_').lower()
+    # add language tag
+    if params['language'] == 'no' or params['language'].startswith('no-'):
+        params['language'] = params['language'].replace('no', 'nb', 1)
+    if params['language'].find('-') < 0:
+        # tries to get a country code from language
+        for lang in supported_languages:
+            lc = lang.split('-')
+            if params['language'] == lc[0]:
+                params['language'] = lang
+                break
+    params['url'] += '&locale=' + params['language'].replace('-', '_').lower()
 
     return params
 
diff --git a/searx/engines/startpage.py b/searx/engines/startpage.py
index 314b7b9a8..3e067597e 100644
--- a/searx/engines/startpage.py
+++ b/searx/engines/startpage.py
@@ -45,9 +45,8 @@ def request(query, params):
     params['data'] = {'query': query,
                       'startat': offset}
 
-    # set language if specified
-    if params['language'] != 'all':
-        params['data']['with_language'] = ('lang_' + params['language'].split('-')[0])
+    # set language
+    params['data']['with_language'] = ('lang_' + params['language'].split('-')[0])
 
     return params
 
diff --git a/searx/engines/subtitleseeker.py b/searx/engines/subtitleseeker.py
index 2cbc991b3..118504ffd 100644
--- a/searx/engines/subtitleseeker.py
+++ b/searx/engines/subtitleseeker.py
@@ -48,7 +48,7 @@ def response(resp):
         search_lang = 'Farsi'
     elif resp.search_params['language'] == 'pt-BR':
         search_lang = 'Brazilian'
-    elif resp.search_params['language'] != 'all':
+    else:
         search_lang = [lc[3]
                        for lc in language_codes
                        if lc[0].split('-')[0] == resp.search_params['language'].split('-')[0]]
diff --git a/searx/engines/swisscows.py b/searx/engines/swisscows.py
index 00346a7d0..45e9d87a9 100644
--- a/searx/engines/swisscows.py
+++ b/searx/engines/swisscows.py
@@ -35,10 +35,7 @@ regex_img_url_remove_start = re.compile(b'^https?://i\.swisscows\.ch/\?link=')
 
 # do search-request
 def request(query, params):
-    if params['language'] == 'all':
-        ui_language = 'browser'
-        region = 'browser'
-    elif params['language'].split('-')[0] == 'no':
+    if params['language'].split('-')[0] == 'no':
         region = 'nb-NO'
     else:
         region = params['language']
diff --git a/searx/engines/twitter.py b/searx/engines/twitter.py
index d2a8d2088..8641167dc 100644
--- a/searx/engines/twitter.py
+++ b/searx/engines/twitter.py
@@ -37,12 +37,7 @@ timestamp_xpath = './/span[contains(@class,"_timestamp")]'
 # do search-request
 def request(query, params):
     params['url'] = search_url + urlencode({'q': query})
-
-    # set language if specified
-    if params['language'] != 'all':
-        params['cookies']['lang'] = params['language'].split('-')[0]
-    else:
-        params['cookies']['lang'] = 'en'
+    params['cookies']['lang'] = params['language'].split('-')[0]
 
     return params
 
diff --git a/searx/engines/wikidata.py b/searx/engines/wikidata.py
index be217463c..1f31a1f88 100644
--- a/searx/engines/wikidata.py
+++ b/searx/engines/wikidata.py
@@ -57,8 +57,6 @@ calendar_name_xpath = './/sup[contains(@class,"wb-calendar-name")]'
 
 def request(query, params):
     language = params['language'].split('-')[0]
-    if language == 'all':
-        language = 'en'
 
     params['url'] = url_search.format(
         query=urlencode({'label': query, 'language': language}))
@@ -71,8 +69,6 @@ def response(resp):
     wikidata_ids = html.xpath(wikidata_ids_xpath)
 
     language = resp.search_params['language'].split('-')[0]
-    if language == 'all':
-        language = 'en'
 
     # TODO: make requests asynchronous to avoid timeout when result_count > 1
     for wikidata_id in wikidata_ids[:result_count]:
diff --git a/searx/engines/wikipedia.py b/searx/engines/wikipedia.py
index db2fdc000..fe82f5115 100644
--- a/searx/engines/wikipedia.py
+++ b/searx/engines/wikipedia.py
@@ -31,7 +31,7 @@ supported_languages_url = 'https://meta.wikimedia.org/wiki/List_of_Wikipedias'
 # set language in base_url
 def url_lang(lang):
     lang = lang.split('-')[0]
-    if lang == 'all' or lang not in supported_languages:
+    if lang not in supported_languages:
         language = 'en'
     else:
         language = lang
diff --git a/searx/engines/yacy.py b/searx/engines/yacy.py
index a62a1296e..c19140bb0 100644
--- a/searx/engines/yacy.py
+++ b/searx/engines/yacy.py
@@ -51,9 +51,7 @@ def request(query, params):
                           limit=number_of_results,
                           search_type=search_type)
 
-    # add language tag if specified
-    if params['language'] != 'all':
-        params['url'] += '&lr=lang_' + params['language'].split('-')[0]
+    params['url'] += '&lr=lang_' + params['language'].split('-')[0]
 
     return params
 
diff --git a/searx/engines/yahoo.py b/searx/engines/yahoo.py
index 5387aaf54..626a398b5 100644
--- a/searx/engines/yahoo.py
+++ b/searx/engines/yahoo.py
@@ -71,9 +71,7 @@ def _get_url(query, offset, language, time_range):
 
 
 def _get_language(params):
-    if params['language'] == 'all':
-        return 'en'
-    elif params['language'][:2] == 'zh':
+    if params['language'][:2] == 'zh':
         if params['language'] == 'zh' or params['language'] == 'zh-CH':
             return 'szh'
         else:
diff --git a/searx/engines/yahoo_news.py b/searx/engines/yahoo_news.py
index ae54a4acd..69e9aef4f 100644
--- a/searx/engines/yahoo_news.py
+++ b/searx/engines/yahoo_news.py
@@ -38,10 +38,7 @@ suggestion_xpath = '//div[contains(@class,"VerALSOTRY")]//a'
 def request(query, params):
     offset = (params['pageno'] - 1) * 10 + 1
 
-    if params['language'] == 'all':
-        language = 'en'
-    else:
-        language = params['language'].split('_')[0]
+    language = params['language'].split('-')[0]
 
     params['url'] = search_url.format(offset=offset,
                                       query=urlencode({'p': query}),
diff --git a/searx/engines/youtube_api.py b/searx/engines/youtube_api.py
index 6de18aa2c..f8bc353f4 100644
--- a/searx/engines/youtube_api.py
+++ b/searx/engines/youtube_api.py
@@ -34,9 +34,7 @@ def request(query, params):
     params['url'] = search_url.format(query=urlencode({'q': query}),
                                       api_key=api_key)
 
-    # add language tag if specified
-    if params['language'] != 'all':
-        params['url'] += '&relevanceLanguage=' + params['language'].split('-')[0]
+    params['url'] += '&relevanceLanguage=' + params['language'].split('-')[0]
 
     return params
 
diff --git a/searx/preferences.py b/searx/preferences.py
index dde4f098a..2faa42697 100644
--- a/searx/preferences.py
+++ b/searx/preferences.py
@@ -12,7 +12,6 @@ if version[0] == '3':
 
 COOKIE_MAX_AGE = 60 * 60 * 24 * 365 * 5  # 5 years
 LANGUAGE_CODES = [l[0] for l in languages]
-LANGUAGE_CODES.append('all')
 DISABLED = 0
 ENABLED = 1
 DOI_RESOLVERS = list(settings['doi_resolvers'])
diff --git a/searx/query.py b/searx/query.py
index e4483f188..6e5f2e883 100644
--- a/searx/query.py
+++ b/searx/query.py
@@ -73,11 +73,6 @@ class RawTextQuery(object):
             if query_part[0] == ':':
                 lang = query_part[1:].lower().replace('_', '-')
 
-                # user may set a valid, yet not selectable language
-                if VALID_LANGUAGE_CODE.match(lang):
-                    self.languages.append(lang)
-                    parse_next = True
-
                 # check if any language-code is equal with
                 # declared language-codes
                 for lc in language_codes:
@@ -85,16 +80,25 @@ class RawTextQuery(object):
 
                     # if correct language-code is found
                     # set it as new search-language
-                    if lang == lang_id\
-                       or lang_id.startswith(lang)\
-                       or lang == lang_name\
-                       or lang == english_name\
-                       or lang.replace('-', ' ') == country:
-                        parse_next = True
-                        self.languages.append(lang_id)
-                        # to ensure best match (first match is not necessarily the best one)
-                        if lang == lang_id:
-                            break
+                    if (lang == lang_id
+                        or lang == lang_name
+                        or lang == english_name
+                        or lang.replace('-', ' ') == country)\
+                       and lang not in self.languages:
+                            parse_next = True
+                            lang_parts = lang_id.split('-')
+                            if len(lang_parts) == 2:
+                                self.languages.append(lang_parts[0] + '-' + lang_parts[1].upper())
+                            else:
+                                self.languages.append(lang_id)
+                            # to ensure best match (first match is not necessarily the best one)
+                            if lang == lang_id:
+                                break
+
+                # user may set a valid, yet not selectable language
+                if not self.languages and VALID_LANGUAGE_CODE.match(lang):
+                    self.languages.append(lang)
+                    parse_next = True
 
             # this force a engine or category
             if query_part[0] == '!' or query_part[0] == '?':
diff --git a/searx/search.py b/searx/search.py
index 1bfb47260..b523c2754 100644
--- a/searx/search.py
+++ b/searx/search.py
@@ -24,7 +24,7 @@ from flask_babel import gettext
 import requests.exceptions
 import searx.poolrequests as requests_lib
 from searx.engines import (
-    categories, engines
+    categories, engines, settings
 )
 from searx.answerers import ask
 from searx.utils import gen_useragent
@@ -220,6 +220,10 @@ def get_search_query_from_webapp(preferences, form):
     else:
         query_lang = preferences.get_value('language')
 
+    # provides backwards compatibility for requests using old language default
+    if query_lang == 'all':
+        query_lang = settings['search']['language']
+
     # check language
     if not VALID_LANGUAGE_CODE.match(query_lang):
         raise SearxParameterException('language', query_lang)
diff --git a/searx/settings.yml b/searx/settings.yml
index 00cac5fe4..e819eadae 100644
--- a/searx/settings.yml
+++ b/searx/settings.yml
@@ -5,7 +5,7 @@ general:
 search:
     safe_search : 0 # Filter results. 0: None, 1: Moderate, 2: Strict
     autocomplete : "" # Existing autocomplete backends: "dbpedia", "duckduckgo", "google", "startpage", "wikipedia" - leave blank to turn it off by default
-    language : "all"
+    language : "en-US"
 
 server:
     port : 8888
diff --git a/searx/settings_robot.yml b/searx/settings_robot.yml
index 070a0edb6..e5f163aef 100644
--- a/searx/settings_robot.yml
+++ b/searx/settings_robot.yml
@@ -5,7 +5,7 @@ general:
 search:
     safe_search : 0
     autocomplete : ""
-    language: "all"
+    language: "en-US"
 
 server:
     port : 11111
diff --git a/searx/templates/courgette/preferences.html b/searx/templates/courgette/preferences.html
index 56a6e0202..61f521477 100644
--- a/searx/templates/courgette/preferences.html
+++ b/searx/templates/courgette/preferences.html
@@ -13,7 +13,6 @@
         <legend>{{ _('Search language') }}</legend>
         <p>
             <select name='language'>
-                <option value="all" {% if current_language == 'all' %}selected="selected"{% endif %}>{{ _('Default language') }}</option>
                 {% for lang_id,lang_name,country_name,english_name in language_codes | sort(attribute=1) %}
                 <option value="{{ lang_id }}" {% if lang_id == current_language %}selected="selected"{% endif %}>{{ lang_name }} {% if country_name %}({{ country_name }}) {% endif %}- {{ lang_id }}</option>
                 {% endfor %}
diff --git a/searx/templates/legacy/preferences.html b/searx/templates/legacy/preferences.html
index f418dcd5b..fb70832e3 100644
--- a/searx/templates/legacy/preferences.html
+++ b/searx/templates/legacy/preferences.html
@@ -14,7 +14,6 @@
         <legend>{{ _('Search language') }}</legend>
         <p>
         <select name='language'>
-            <option value="all" {% if current_language == 'all' %}selected="selected"{% endif %}>{{ _('Default language') }}</option>
             {% for lang_id,lang_name,country_name,english_name in language_codes | sort(attribute=1) %}
             <option value="{{ lang_id }}" {% if lang_id == current_language %}selected="selected"{% endif %}>{{ lang_name }} {% if country_name %}({{ country_name }}) {% endif %}- {{ lang_id }}</option>
             {% endfor %}
diff --git a/searx/templates/oscar/languages.html b/searx/templates/oscar/languages.html
index 96c1c3a9c..996c427bd 100644
--- a/searx/templates/oscar/languages.html
+++ b/searx/templates/oscar/languages.html
@@ -3,10 +3,9 @@
 {% else %}
 <select class="time_range custom-select form-control" id='language' name='language'>
 {% endif %}
-	<option value="all" {% if current_language == 'all' %}selected="selected"{% endif %}>{{ _('Default language') }}</option>
-		{% for lang_id,lang_name,country_name,english_name in language_codes | sort(attribute=1) %}
-		<option value="{{ lang_id }}" {% if lang_id == current_language %}selected="selected"{% endif %}>
-			{{ lang_name }} {% if country_name %}({{ country_name }}) {% endif %}- {{ lang_id }}
-		</option>
-		{% endfor %}
+	{% for lang_id,lang_name,country_name,english_name in language_codes | sort(attribute=1) %}
+	<option value="{{ lang_id }}" {% if lang_id == current_language %}selected="selected"{% endif %}>
+		{{ lang_name }} {% if country_name %}({{ country_name }}) {% endif %}- {{ lang_id }}
+	</option>
+	{% endfor %}
 </select>
diff --git a/searx/templates/oscar/preferences.html b/searx/templates/oscar/preferences.html
index ac62dc939..89eb99c1f 100644
--- a/searx/templates/oscar/preferences.html
+++ b/searx/templates/oscar/preferences.html
@@ -187,7 +187,7 @@
                                     </td>
                                     <th>{{ search_engine.name }}</th>
 				    <td class="name">{{ shortcuts[search_engine.name] }}</td>
-					<td>{{ support_toggle(current_language == 'all' or current_language in search_engine.supported_languages or current_language.split('-')[0] in search_engine.supported_languages) }}</td>
+					<td>{{ support_toggle(current_language in search_engine.supported_languages or current_language.split('-')[0] in search_engine.supported_languages) }}</td>
 					<td>{{ support_toggle(search_engine.safesearch==True) }}</td>
 					<td>{{ support_toggle(search_engine.time_range_support==True) }}</td>
 					<td class="{{ 'danger' if stats[search_engine.name]['warn_time'] else '' }}">{{ 'N/A' if stats[search_engine.name].time==None else stats[search_engine.name].time }}</td>
@@ -197,7 +197,7 @@
 					<td class="{{ 'danger' if stats[search_engine.name]['warn_time'] else '' }}">{{ 'N/A' if stats[search_engine.name].time==None else stats[search_engine.name].time }}</td>
 					<td>{{ support_toggle(search_engine.time_range_support==True) }}</td>
 					<td>{{ support_toggle(search_engine.safesearch==True) }}</td>
-					<td>{{ support_toggle(current_language == 'all' or current_language in search_engine.supported_languages or current_language.split('-')[0] in search_engine.supported_languages) }}</td>
+					<td>{{ support_toggle(current_language in search_engine.supported_languages or current_language.split('-')[0] in search_engine.supported_languages) }}</td>
 					<td>{{ shortcuts[search_engine.name] }}</td>
                                     <th>{{ search_engine.name }}</th>
                                     <td class="onoff-checkbox">
diff --git a/searx/templates/pix-art/preferences.html b/searx/templates/pix-art/preferences.html
index 05876dedf..0b2bb6709 100644
--- a/searx/templates/pix-art/preferences.html
+++ b/searx/templates/pix-art/preferences.html
@@ -9,7 +9,6 @@
         <legend>{{ _('Search language') }}</legend>
         <p>
         <select name='language'>
-            <option value="all" {% if current_language == 'all' %}selected="selected"{% endif %}>{{ _('Default language') }}</option>
             {% for lang_id,lang_name,country_name,english_name in language_codes | sort(attribute=1) %}
             <option value="{{ lang_id }}" {% if lang_id == current_language %}selected="selected"{% endif %}>{{ lang_name }} {% if country_name %}({{ country_name }}) {% endif %}- {{ lang_id }}</option>
             {% endfor %}
diff --git a/searx/webapp.py b/searx/webapp.py
index abbbce950..431ecbc34 100644
--- a/searx/webapp.py
+++ b/searx/webapp.py
@@ -628,8 +628,8 @@ def autocompleter():
     if len(raw_results) <= 3 and completer:
         # get language from cookie
         language = request.preferences.get_value('language')
-        if not language or language == 'all':
-            language = 'en'
+        if not language:
+            language = settings['search']['language']
         else:
             language = language.split('-')[0]
         # run autocompletion
diff --git a/tests/unit/engines/test_archlinux.py b/tests/unit/engines/test_archlinux.py
index e4ee0339c..f9e536f4e 100644
--- a/tests/unit/engines/test_archlinux.py
+++ b/tests/unit/engines/test_archlinux.py
@@ -4,7 +4,7 @@ from searx.engines import archlinux
 from searx.testing import SearxTestCase
 
 domains = {
-    'all': 'https://wiki.archlinux.org',
+    'en': 'https://wiki.archlinux.org',
     'de': 'https://wiki.archlinux.de',
     'fr': 'https://wiki.archlinux.fr',
     'ja': 'https://wiki.archlinuxjp.org',
diff --git a/tests/unit/engines/test_bing.py b/tests/unit/engines/test_bing.py
index 523ec57b8..2528dd847 100644
--- a/tests/unit/engines/test_bing.py
+++ b/tests/unit/engines/test_bing.py
@@ -10,17 +10,13 @@ class TestBingEngine(SearxTestCase):
         query = u'test_query'
         dicto = defaultdict(dict)
         dicto['pageno'] = 0
-        dicto['language'] = 'fr_FR'
+        dicto['language'] = 'fr-FR'
         params = bing.request(query.encode('utf-8'), dicto)
         self.assertTrue('url' in params)
         self.assertTrue(query in params['url'])
         self.assertTrue('language%3AFR' in params['url'])
         self.assertTrue('bing.com' in params['url'])
 
-        dicto['language'] = 'all'
-        params = bing.request(query.encode('utf-8'), dicto)
-        self.assertTrue('language' in params['url'])
-
     def test_response(self):
         self.assertRaises(AttributeError, bing.response, None)
         self.assertRaises(AttributeError, bing.response, [])
diff --git a/tests/unit/engines/test_bing_news.py b/tests/unit/engines/test_bing_news.py
index 1f1aeca1d..3af19fd6d 100644
--- a/tests/unit/engines/test_bing_news.py
+++ b/tests/unit/engines/test_bing_news.py
@@ -19,10 +19,6 @@ class TestBingNewsEngine(SearxTestCase):
         self.assertIn('bing.com', params['url'])
         self.assertIn('fr', params['url'])
 
-        dicto['language'] = 'all'
-        params = bing_news.request(query, dicto)
-        self.assertIn('en', params['url'])
-
     def test_no_url_in_request_year_time_range(self):
         dicto = defaultdict(dict)
         query = 'test_query'
diff --git a/tests/unit/engines/test_dailymotion.py b/tests/unit/engines/test_dailymotion.py
index 72071af66..2009c0e4f 100644
--- a/tests/unit/engines/test_dailymotion.py
+++ b/tests/unit/engines/test_dailymotion.py
@@ -18,10 +18,6 @@ class TestDailymotionEngine(SearxTestCase):
         self.assertTrue('dailymotion.com' in params['url'])
         self.assertTrue('fr' in params['url'])
 
-        dicto['language'] = 'all'
-        params = dailymotion.request(query, dicto)
-        self.assertTrue('en' in params['url'])
-
     def test_response(self):
         self.assertRaises(AttributeError, dailymotion.response, None)
         self.assertRaises(AttributeError, dailymotion.response, [])
diff --git a/tests/unit/engines/test_duckduckgo_images.py b/tests/unit/engines/test_duckduckgo_images.py
index a8a57c7fd..582163130 100644
--- a/tests/unit/engines/test_duckduckgo_images.py
+++ b/tests/unit/engines/test_duckduckgo_images.py
@@ -15,7 +15,7 @@ class TestDuckduckgoImagesEngine(SearxTestCase):
         dicto['is_test'] = True
         dicto['pageno'] = 1
         dicto['safesearch'] = 0
-        dicto['language'] = 'all'
+        dicto['language'] = 'en-US'
         params = duckduckgo_images.request(query, dicto)
         self.assertIn('url', params)
         self.assertIn(query, params['url'])
diff --git a/tests/unit/engines/test_faroo.py b/tests/unit/engines/test_faroo.py
index ebcde39a7..0cc8bc3e0 100644
--- a/tests/unit/engines/test_faroo.py
+++ b/tests/unit/engines/test_faroo.py
@@ -11,7 +11,7 @@ class TestFarooEngine(SearxTestCase):
         query = 'test_query'
         dicto = defaultdict(dict)
         dicto['pageno'] = 1
-        dicto['language'] = 'fr_FR'
+        dicto['language'] = 'fr-FR'
         dicto['category'] = 'general'
         params = faroo.request(query, dicto)
         self.assertIn('url', params)
@@ -20,11 +20,7 @@ class TestFarooEngine(SearxTestCase):
         self.assertIn('en', params['url'])
         self.assertIn('web', params['url'])
 
-        dicto['language'] = 'all'
-        params = faroo.request(query, dicto)
-        self.assertIn('en', params['url'])
-
-        dicto['language'] = 'de_DE'
+        dicto['language'] = 'de-DE'
         params = faroo.request(query, dicto)
         self.assertIn('de', params['url'])
 
diff --git a/tests/unit/engines/test_gigablast.py b/tests/unit/engines/test_gigablast.py
index 6b2d26458..f0ddb63bc 100644
--- a/tests/unit/engines/test_gigablast.py
+++ b/tests/unit/engines/test_gigablast.py
@@ -11,16 +11,11 @@ class TestGigablastEngine(SearxTestCase):
         dicto = defaultdict(dict)
         dicto['pageno'] = 0
         dicto['safesearch'] = 0
-        dicto['language'] = 'all'
+        dicto['language'] = 'en-US'
         params = gigablast.request(query, dicto)
         self.assertTrue('url' in params)
         self.assertTrue(query in params['url'])
         self.assertTrue('gigablast.com' in params['url'])
-        self.assertTrue('xx' in params['url'])
-
-        dicto['language'] = 'en-US'
-        params = gigablast.request(query, dicto)
-        self.assertTrue('en' in params['url'])
         self.assertFalse('en-US' in params['url'])
 
     def test_response(self):
diff --git a/tests/unit/engines/test_google.py b/tests/unit/engines/test_google.py
index 0498d49b0..ecd1ed4d9 100644
--- a/tests/unit/engines/test_google.py
+++ b/tests/unit/engines/test_google.py
@@ -26,7 +26,7 @@ class TestGoogleEngine(SearxTestCase):
         self.assertIn('google.fr', params['url'])
         self.assertIn('fr', params['headers']['Accept-Language'])
 
-        dicto['language'] = 'all'
+        dicto['language'] = 'en-US'
         params = google.request(query, dicto)
         self.assertIn('google.co', params['url'])
         self.assertIn('en', params['headers']['Accept-Language'])
diff --git a/tests/unit/engines/test_google_news.py b/tests/unit/engines/test_google_news.py
index 20a75af48..3769e3be6 100644
--- a/tests/unit/engines/test_google_news.py
+++ b/tests/unit/engines/test_google_news.py
@@ -12,18 +12,13 @@ class TestGoogleNewsEngine(SearxTestCase):
         query = 'test_query'
         dicto = defaultdict(dict)
         dicto['pageno'] = 1
-        dicto['language'] = 'fr_FR'
+        dicto['language'] = 'fr-FR'
         dicto['time_range'] = 'w'
         params = google_news.request(query, dicto)
         self.assertIn('url', params)
         self.assertIn(query, params['url'])
         self.assertIn('fr', params['url'])
 
-        dicto['language'] = 'all'
-        params = google_news.request(query, dicto)
-        self.assertIn('url', params)
-        self.assertNotIn('fr', params['url'])
-
     def test_response(self):
         self.assertRaises(AttributeError, google_news.response, None)
         self.assertRaises(AttributeError, google_news.response, [])
diff --git a/tests/unit/engines/test_mediawiki.py b/tests/unit/engines/test_mediawiki.py
index b86372700..1b07dd8f4 100644
--- a/tests/unit/engines/test_mediawiki.py
+++ b/tests/unit/engines/test_mediawiki.py
@@ -18,10 +18,6 @@ class TestMediawikiEngine(SearxTestCase):
         self.assertIn('wikipedia.org', params['url'])
         self.assertIn('fr', params['url'])
 
-        dicto['language'] = 'all'
-        params = mediawiki.request(query, dicto)
-        self.assertIn('en', params['url'])
-
         mediawiki.base_url = "http://test.url/"
         mediawiki.search_url = mediawiki.base_url +\
                                  'w/api.php?action=query'\
diff --git a/tests/unit/engines/test_qwant.py b/tests/unit/engines/test_qwant.py
index b7133c076..46694988c 100644
--- a/tests/unit/engines/test_qwant.py
+++ b/tests/unit/engines/test_qwant.py
@@ -19,10 +19,11 @@ class TestQwantEngine(SearxTestCase):
         self.assertIn('qwant.com', params['url'])
         self.assertIn('fr_fr', params['url'])
 
-        dicto['language'] = 'all'
+        dicto['language'] = 'en-US'
         qwant.categories = ['news']
         params = qwant.request(query, dicto)
         self.assertFalse('fr' in params['url'])
+        self.assertIn('en_us', params['url'])
         self.assertIn('news', params['url'])
 
         qwant.supported_languages = ['en', 'fr-FR', 'fr-CA']
diff --git a/tests/unit/engines/test_startpage.py b/tests/unit/engines/test_startpage.py
index a7a97785e..bdb3356b7 100644
--- a/tests/unit/engines/test_startpage.py
+++ b/tests/unit/engines/test_startpage.py
@@ -21,10 +21,6 @@ class TestStartpageEngine(SearxTestCase):
         self.assertIn('with_language', params['data'])
         self.assertIn('lang_fr', params['data']['with_language'])
 
-        dicto['language'] = 'all'
-        params = startpage.request(query, dicto)
-        self.assertNotIn('with_language', params['data'])
-
     def test_response(self):
         self.assertRaises(AttributeError, startpage.response, None)
         self.assertRaises(AttributeError, startpage.response, [])
diff --git a/tests/unit/engines/test_subtitleseeker.py b/tests/unit/engines/test_subtitleseeker.py
index a22ee74b9..96b253943 100644
--- a/tests/unit/engines/test_subtitleseeker.py
+++ b/tests/unit/engines/test_subtitleseeker.py
@@ -73,42 +73,6 @@ class TestSubtitleseekerEngine(SearxTestCase):
         results = subtitleseeker.response(response)
         self.assertEqual(results[0]['url'], 'http://this.is.the.url/Brazilian/')
 
-        html = """
-        <div class="boxRows">
-            <div class="boxRowsInner" style="width:600px;">
-                <img src="http://static.subtitleseeker.com/images/movie.gif"
-                    style="width:16px; height:16px;" class="icon">
-                <a href="http://this.is.the.url/"
-                    class="blue" title="Title subtitle" >
-                    This is the Title
-                </a>
-            </div>
-            <div class="boxRowsInner f12b red" style="width:70px;">
-                1998
-            </div>
-            <div class="boxRowsInner grey-web f12" style="width:120px;">
-                <img src="http://static.subtitleseeker.com/images/basket_put.png"
-                    style="width:16px; height:16px;" class="icon">
-                1039 Subs
-            </div>
-            <div class="boxRowsInner grey-web f10" style="width:130px;">
-                <img src="http://static.subtitleseeker.com/images/arrow_refresh_small.png"
-                    style="width:16px; height:16px;" class="icon">
-                1 hours ago
-            </div>
-            <div class="clear"></div>
-        </div>
-        """
-        dicto['language'] = 'all'
-        response = mock.Mock(text=html, search_params=dicto)
-        results = subtitleseeker.response(response)
-        self.assertEqual(type(results), list)
-        self.assertEqual(len(results), 1)
-        self.assertEqual(results[0]['title'], 'This is the Title')
-        self.assertEqual(results[0]['url'], 'http://this.is.the.url/')
-        self.assertIn('1998', results[0]['content'])
-        self.assertIn('1039 Subs', results[0]['content'])
-
         html = """
         <div class="boxRows">
             <div class="boxRowsInner" style="width:600px;">
diff --git a/tests/unit/engines/test_swisscows.py b/tests/unit/engines/test_swisscows.py
index 492526f94..2715ef52e 100644
--- a/tests/unit/engines/test_swisscows.py
+++ b/tests/unit/engines/test_swisscows.py
@@ -18,11 +18,6 @@ class TestSwisscowsEngine(SearxTestCase):
         self.assertTrue('uiLanguage=de' in params['url'])
         self.assertTrue('region=de-DE' in params['url'])
 
-        dicto['language'] = 'all'
-        params = swisscows.request(query, dicto)
-        self.assertTrue('uiLanguage=browser' in params['url'])
-        self.assertTrue('region=browser' in params['url'])
-
         dicto['category'] = 'images'
         params = swisscows.request(query, dicto)
         self.assertIn('image', params['url'])
diff --git a/tests/unit/engines/test_twitter.py b/tests/unit/engines/test_twitter.py
index b444b48ee..10e4a0ba9 100644
--- a/tests/unit/engines/test_twitter.py
+++ b/tests/unit/engines/test_twitter.py
@@ -20,12 +20,6 @@ class TestTwitterEngine(SearxTestCase):
         self.assertIn('lang', params['cookies'])
         self.assertIn('fr', params['cookies']['lang'])
 
-        dicto['language'] = 'all'
-        params = twitter.request(query, dicto)
-        self.assertIn('cookies', params)
-        self.assertIn('lang', params['cookies'])
-        self.assertIn('en', params['cookies']['lang'])
-
     def test_response(self):
         self.assertRaises(AttributeError, twitter.response, None)
         self.assertRaises(AttributeError, twitter.response, [])
diff --git a/tests/unit/engines/test_wikidata.py b/tests/unit/engines/test_wikidata.py
index aa69f116e..453133b64 100644
--- a/tests/unit/engines/test_wikidata.py
+++ b/tests/unit/engines/test_wikidata.py
@@ -11,14 +11,14 @@ class TestWikidataEngine(SearxTestCase):
     def test_request(self):
         query = 'test_query'
         dicto = defaultdict(dict)
-        dicto['language'] = 'all'
+        dicto['language'] = 'en-US'
         params = wikidata.request(query, dicto)
         self.assertIn('url', params)
         self.assertIn(query, params['url'])
         self.assertIn('wikidata.org', params['url'])
         self.assertIn('en', params['url'])
 
-        dicto['language'] = 'es_ES'
+        dicto['language'] = 'es-ES'
         params = wikidata.request(query, dicto)
         self.assertIn(query, params['url'])
         self.assertIn('es', params['url'])
@@ -30,7 +30,7 @@ class TestWikidataEngine(SearxTestCase):
         self.assertRaises(AttributeError, wikidata.response, '')
         self.assertRaises(AttributeError, wikidata.response, '[]')
 
-        response = mock.Mock(text='<html></html>', search_params={"language": "all"})
+        response = mock.Mock(text='<html></html>', search_params={"language": "en"})
         self.assertEqual(wikidata.response(response), [])
 
     def test_getDetail(self):
diff --git a/tests/unit/engines/test_wikipedia.py b/tests/unit/engines/test_wikipedia.py
index 7a86514c7..21d0225ed 100644
--- a/tests/unit/engines/test_wikipedia.py
+++ b/tests/unit/engines/test_wikipedia.py
@@ -25,10 +25,6 @@ class TestWikipediaEngine(SearxTestCase):
         self.assertIn('Test_Query', params['url'])
         self.assertNotIn('test_query', params['url'])
 
-        dicto['language'] = 'all'
-        params = wikipedia.request(query, dicto)
-        self.assertIn('en', params['url'])
-
         dicto['language'] = 'xx'
         params = wikipedia.request(query, dicto)
         self.assertIn('en', params['url'])
diff --git a/tests/unit/engines/test_yacy.py b/tests/unit/engines/test_yacy.py
index f49532cf4..a60614d3d 100644
--- a/tests/unit/engines/test_yacy.py
+++ b/tests/unit/engines/test_yacy.py
@@ -17,11 +17,6 @@ class TestYacyEngine(SearxTestCase):
         self.assertIn('localhost', params['url'])
         self.assertIn('fr', params['url'])
 
-        dicto['language'] = 'all'
-        params = yacy.request(query, dicto)
-        self.assertIn('url', params)
-        self.assertNotIn('lr=lang_', params['url'])
-
     def test_response(self):
         self.assertRaises(AttributeError, yacy.response, None)
         self.assertRaises(AttributeError, yacy.response, [])
diff --git a/tests/unit/engines/test_yahoo.py b/tests/unit/engines/test_yahoo.py
index 82c4d99bb..921d3e8cd 100644
--- a/tests/unit/engines/test_yahoo.py
+++ b/tests/unit/engines/test_yahoo.py
@@ -39,13 +39,6 @@ class TestYahooEngine(SearxTestCase):
         self.assertIn('sB', params['cookies'])
         self.assertIn('fr', params['cookies']['sB'])
 
-        dicto['language'] = 'all'
-        params = yahoo.request(query, dicto)
-        self.assertIn('cookies', params)
-        self.assertIn('sB', params['cookies'])
-        self.assertIn('en', params['cookies']['sB'])
-        self.assertIn('en', params['url'])
-
     def test_no_url_in_request_year_time_range(self):
         dicto = defaultdict(dict)
         query = 'test_query'
diff --git a/tests/unit/engines/test_yahoo_news.py b/tests/unit/engines/test_yahoo_news.py
index 4d7fc0a10..bc87ec067 100644
--- a/tests/unit/engines/test_yahoo_news.py
+++ b/tests/unit/engines/test_yahoo_news.py
@@ -22,13 +22,6 @@ class TestYahooNewsEngine(SearxTestCase):
         self.assertIn('sB', params['cookies'])
         self.assertIn('fr', params['cookies']['sB'])
 
-        dicto['language'] = 'all'
-        params = yahoo_news.request(query, dicto)
-        self.assertIn('cookies', params)
-        self.assertIn('sB', params['cookies'])
-        self.assertIn('en', params['cookies']['sB'])
-        self.assertIn('en', params['url'])
-
     def test_sanitize_url(self):
         url = "test.url"
         self.assertEqual(url, yahoo_news.sanitize_url(url))
diff --git a/tests/unit/test_preferences.py b/tests/unit/test_preferences.py
index 885c515e2..c8f2a4419 100644
--- a/tests/unit/test_preferences.py
+++ b/tests/unit/test_preferences.py
@@ -90,25 +90,30 @@ class TestSettings(SearxTestCase):
 
     # search language settings
     def test_lang_setting_valid_choice(self):
-        setting = SearchLanguageSetting('all', choices=['all', 'de', 'en'])
+        setting = SearchLanguageSetting('en', choices=['de', 'en'])
         setting.parse('de')
         self.assertEquals(setting.get_value(), 'de')
 
     def test_lang_setting_invalid_choice(self):
-        setting = SearchLanguageSetting('all', choices=['all', 'de', 'en'])
+        setting = SearchLanguageSetting('en', choices=['de', 'en'])
         setting.parse('xx')
-        self.assertEquals(setting.get_value(), 'all')
+        self.assertEquals(setting.get_value(), 'en')
 
     def test_lang_setting_old_cookie_choice(self):
-        setting = SearchLanguageSetting('all', choices=['all', 'es', 'es-ES'])
+        setting = SearchLanguageSetting('en', choices=['en', 'es', 'es-ES'])
         setting.parse('es_XA')
         self.assertEquals(setting.get_value(), 'es')
 
     def test_lang_setting_old_cookie_format(self):
-        setting = SearchLanguageSetting('all', choices=['all', 'es', 'es-ES'])
+        setting = SearchLanguageSetting('en', choices=['en', 'es', 'es-ES'])
         setting.parse('es_ES')
         self.assertEquals(setting.get_value(), 'es-ES')
 
+    def test_lang_setting_old_default(self):
+        setting = SearchLanguageSetting('en', choices=['en', 'es', 'de'])
+        setting.parse('all')
+        self.assertEquals(setting.get_value(), 'en')
+
     # plugins settings
     def test_plugins_setting_all_default_enabled(self):
         plugin1 = PluginStub('plugin1', True)
diff --git a/tests/unit/test_query.py b/tests/unit/test_query.py
new file mode 100644
index 000000000..49ccb608f
--- /dev/null
+++ b/tests/unit/test_query.py
@@ -0,0 +1,64 @@
+from searx.query import RawTextQuery
+from searx.testing import SearxTestCase
+
+
+class TestQuery(SearxTestCase):
+
+    def test_simple_query(self):
+        query_text = 'the query'
+        query = RawTextQuery(query_text, [])
+        query.parse_query()
+
+        self.assertEquals(query.getFullQuery(), query_text)
+        self.assertEquals(len(query.query_parts), 1)
+        self.assertEquals(len(query.languages), 0)
+        self.assertFalse(query.specific)
+
+    def test_language_code(self):
+        language = 'es-ES'
+        query_text = 'the query'
+        full_query = ':' + language + ' ' + query_text
+        query = RawTextQuery(full_query, [])
+        query.parse_query()
+
+        self.assertEquals(query.getFullQuery(), full_query)
+        self.assertEquals(len(query.query_parts), 3)
+        self.assertEquals(len(query.languages), 1)
+        self.assertIn(language, query.languages)
+        self.assertFalse(query.specific)
+
+    def test_language_name(self):
+        language = 'english'
+        query_text = 'the query'
+        full_query = ':' + language + ' ' + query_text
+        query = RawTextQuery(full_query, [])
+        query.parse_query()
+
+        self.assertEquals(query.getFullQuery(), full_query)
+        self.assertEquals(len(query.query_parts), 3)
+        self.assertIn('en', query.languages)
+        self.assertFalse(query.specific)
+
+    def test_unlisted_language_code(self):
+        language = 'all'
+        query_text = 'the query'
+        full_query = ':' + language + ' ' + query_text
+        query = RawTextQuery(full_query, [])
+        query.parse_query()
+
+        self.assertEquals(query.getFullQuery(), full_query)
+        self.assertEquals(len(query.query_parts), 3)
+        self.assertIn('all', query.languages)
+        self.assertFalse(query.specific)
+
+    def test_invalid_language_code(self):
+        language = 'not_a_language'
+        query_text = 'the query'
+        full_query = ':' + language + ' ' + query_text
+        query = RawTextQuery(full_query, [])
+        query.parse_query()
+
+        self.assertEquals(query.getFullQuery(), full_query)
+        self.assertEquals(len(query.query_parts), 1)
+        self.assertEquals(len(query.languages), 0)
+        self.assertFalse(query.specific)