diff --git a/swh/web/api/views/origin.py b/swh/web/api/views/origin.py
--- a/swh/web/api/views/origin.py
+++ b/swh/web/api/views/origin.py
@@ -194,11 +194,9 @@
             and only the Link header should be used for paginating through
             results.
 
-        :param string url_pattern: a string pattern or a regular expression
+        :param string url_pattern: a string pattern
         :query int limit: the maximum number of found origins to return
             (bounded to 1000)
-        :query boolean regexp: if true, consider provided pattern as a regular
-            expression and search origins whose urls match it
         :query boolean with_visit: if true, only return origins with at least
             one visit by Software heritage
 
@@ -221,11 +219,10 @@
     result = {}
     offset = int(request.query_params.get('offset', '0'))
     limit = min(int(request.query_params.get('limit', '70')), 1000)
-    regexp = request.query_params.get('regexp', 'false')
     with_visit = request.query_params.get('with_visit', 'false')
 
     results = api_lookup(service.search_origin, url_pattern, offset, limit,
-                         bool(strtobool(regexp)), bool(strtobool(with_visit)),
+                         bool(strtobool(with_visit)),
                          enrich_fn=_enrich_origin)
 
     nb_results = len(results)
@@ -233,7 +230,6 @@
         query_params = {}
         query_params['offset'] = offset + limit
         query_params['limit'] = limit
-        query_params['regexp'] = regexp
 
         result['headers'] = {
             'link-next': reverse('api-1-origin-search',
diff --git a/swh/web/common/service.py b/swh/web/common/service.py
--- a/swh/web/common/service.py
+++ b/swh/web/common/service.py
@@ -247,8 +247,7 @@
     return map(converters.from_origin, origins)
 
 
-def search_origin(url_pattern, offset=0, limit=50, regexp=False,
-                  with_visit=False):
+def search_origin(url_pattern, offset=0, limit=50, with_visit=False):
     """Search for origins whose urls contain a provided string pattern
     or match a provided regular expression.
 
@@ -261,17 +260,15 @@
         list of origin information as dict.
 
     """
-    if not regexp:
-        # If the query is not a regexp, rewrite it as a regexp.
-        regexp = True
-        search_words = [re.escape(word) for word in url_pattern.split()]
-        if len(search_words) >= 7:
-            url_pattern = '.*'.join(search_words)
-        else:
-            pattern_parts = []
-            for permut in itertools.permutations(search_words):
-                pattern_parts.append('.*'.join(permut))
-            url_pattern = '|'.join(pattern_parts)
+    regexp = True
+    search_words = [re.escape(word) for word in url_pattern.split()]
+    if len(search_words) >= 7:
+        url_pattern = '.*'.join(search_words)
+    else:
+        pattern_parts = []
+        for permut in itertools.permutations(search_words):
+            pattern_parts.append('.*'.join(permut))
+        url_pattern = '|'.join(pattern_parts)
 
     origins = storage.origin_search(url_pattern, offset, limit, regexp,
                                     with_visit)
diff --git a/swh/web/tests/api/views/test_origin.py b/swh/web/tests/api/views/test_origin.py
--- a/swh/web/tests/api/views/test_origin.py
+++ b/swh/web/tests/api/views/test_origin.py
@@ -497,22 +497,6 @@
         == {'https://github.com/memononen/libtess2'}
 
 
-def test_api_origin_search_regexp(api_client):
-    expected_origins = {
-        'https://github.com/memononen/libtess2',
-        'repo_with_submodules'
-    }
-
-    url = reverse('api-1-origin-search',
-                  url_args={'url_pattern': '(repo|libtess)'},
-                  query_params={'limit': 10,
-                                'regexp': True})
-    rv = api_client.get(url)
-    assert rv.status_code == 200, rv.data
-    assert rv['Content-Type'] == 'application/json'
-    assert {origin['url'] for origin in rv.data} == expected_origins
-
-
 @pytest.mark.parametrize('limit', [1, 2, 3, 10])
 def test_api_origin_search_scroll(api_client, archive_data, limit):
     expected_origins = {