diff --git a/swh/web/ui/converters.py b/swh/web/ui/converters.py
--- a/swh/web/ui/converters.py
+++ b/swh/web/ui/converters.py
@@ -5,6 +5,7 @@
 
 import datetime
 
+from swh.core.utils import decode_with_escape
 from swh.core import hashutil
 from swh.web.ui import utils
 
@@ -86,7 +87,10 @@
         elif key in hashess:
             new_dict[key] = utils.fmap(convert_hashes_bytes, value)
         elif key in bytess:
-            new_dict[key] = utils.fmap(convert_bytes, value)
+            try:
+                new_dict[key] = utils.fmap(convert_bytes, value)
+            except UnicodeDecodeError:
+                new_dict[key] = utils.fmap(decode_with_escape, value)
         elif key in convert:
             new_dict[key] = convert_fn(value)
         else:
diff --git a/swh/web/ui/tests/test_converters.py b/swh/web/ui/tests/test_converters.py
--- a/swh/web/ui/tests/test_converters.py
+++ b/swh/web/ui/tests/test_converters.py
@@ -100,6 +100,28 @@
         self.assertEquals(expected_output, actual_output)
 
     @istest
+    def from_swh_edge_cases_convert_invalid_utf8_bytes(self):
+        some_input = {
+            'a': 'something',
+            'b': 'someone',
+            'c': b'a name \xff',
+            'd': b'an email \xff',
+        }
+
+        expected_output = {
+            'a': 'something',
+            'b': 'someone',
+            'c': 'a name \\xff',
+            'd': 'an email \\xff',
+        }
+
+        actual_output = converters.from_swh(some_input,
+                                            hashess={'a', 'b'},
+                                            bytess={'c', 'd'})
+
+        self.assertEquals(expected_output, actual_output)
+
+    @istest
     def from_swh_empty(self):
         # when
         self.assertEquals({}, converters.from_swh({}))