diff --git a/swh/web/browse/views/content.py b/swh/web/browse/views/content.py
--- a/swh/web/browse/views/content.py
+++ b/swh/web/browse/views/content.py
@@ -5,6 +5,7 @@
 
 import difflib
 import json
+import mimetypes
 
 from distutils.util import strtobool
 
@@ -48,8 +49,14 @@
     if not filename:
         filename = '%s_%s' % (algo, checksum)
 
-    if content_data['mimetype'].startswith('text/') or \
-       content_data['mimetype'] == 'inode/x-empty':
+    if content_data['mimetype'].startswith('text/'):
+        response = HttpResponse(content_data['raw_data'],
+                                content_type="text/plain")
+        # Guess file extension by detected mime types
+        if content_data['mimetype'] != "text/plain":
+            filename += mimetypes.guess_extension(content_data['mimetype'])
+        response['Content-disposition'] = 'filename=%s' % filename
+    elif content_data['mimetype'] == 'inode/x-empty':
         response = HttpResponse(content_data['raw_data'],
                                 content_type="text/plain")
         response['Content-disposition'] = 'filename=%s' % filename