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
@@ -6,6 +6,7 @@
 import datetime
 
 from swh.core import hashutil
+from swh.core.utils import decode_with_escape
 from swh.web.ui import utils
 
 
@@ -86,7 +87,14 @@
         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:
+                if 'decoding_failures' not in new_dict:
+                    new_dict['decoding_failures'] = [key]
+                else:
+                    new_dict['decoding_failures'].append(key)
+                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/templates/content.html b/swh/web/ui/templates/content.html
--- a/swh/web/ui/templates/content.html
+++ b/swh/web/ui/templates/content.html
@@ -24,5 +24,10 @@
        <div class="col-md-10"><pre>{{ content['data'] }}</pre></div>
     </div>
     {% endif %}
+    {% if 'decoding_failures' in content %}
+    <div class="row">
+      <div class="col-md-10">(some decoding errors)</div>
+    </div>
+    {% endif %}
   {% endif %}
 {% endblock %}
diff --git a/swh/web/ui/templates/directory.html b/swh/web/ui/templates/directory.html
--- a/swh/web/ui/templates/directory.html
+++ b/swh/web/ui/templates/directory.html
@@ -4,7 +4,12 @@
 {{ message }}
 {% if ls is not none %}
   {% for e in files %}
-    <div><p><a class="link{{e.type}}" href="{{e.target_url}}">{{ e.name }}</a></p></div>
+<div>
+  <p>
+    <a class="link{{e.type}}" href="{{e.target_url}}">{{ e.name }}</a>
+    {% if 'decoding_failures' in e %}(some decoding errors){% endif %}
+  </p>
+</div>
   {% endfor %}
 {% endif %}
 {% endblock %}
diff --git a/swh/web/ui/templates/entity.html b/swh/web/ui/templates/entity.html
--- a/swh/web/ui/templates/entity.html
+++ b/swh/web/ui/templates/entity.html
@@ -18,6 +18,11 @@
          </div>
          {% endif %}
        {% endfor %}
+         {% if 'decoding_failures' in entity %}
+	 <div class="row">
+	   <div class="col-md-10">(some decoding errors)</div>
+	 </div>
+	 {% endif %}
     {% endfor %}
   {% endif %}
 {% endblock %}
diff --git a/swh/web/ui/templates/origin.html b/swh/web/ui/templates/origin.html
--- a/swh/web/ui/templates/origin.html
+++ b/swh/web/ui/templates/origin.html
@@ -16,6 +16,11 @@
             </div>
         {% endif %}
     {% endfor %}
+	{% if 'decoding_failures' in content %}
+	    <div class="row">
+	      <div class="col-md-10">(some decoding errors)</div>
+	    </div>
+	{% endif %}    
 </div>
 {% endif %}
 
diff --git a/swh/web/ui/templates/person.html b/swh/web/ui/templates/person.html
--- a/swh/web/ui/templates/person.html
+++ b/swh/web/ui/templates/person.html
@@ -16,6 +16,11 @@
             </div>
         {% endif %}
     {% endfor %}
+    {% if 'decoding_failures' in person %}
+    <div class="row">
+      <div class="col-md-10">(some decoding errors)</div>
+    </div>
+    {% endif %}
 </div>
 {% endif %}
 
diff --git a/swh/web/ui/templates/release.html b/swh/web/ui/templates/release.html
--- a/swh/web/ui/templates/release.html
+++ b/swh/web/ui/templates/release.html
@@ -9,7 +9,7 @@
 {% if release is not none %}
 <div>
   {% for key in release.keys() %}
-    {% if key not in ['author', 'target_url', 'message', 'target', 'target_type'] and release[key] is not none %}
+    {% if key not in ['author', 'target_url', 'message', 'target', 'target_type', 'decoding_failures'] and release[key] is not none %}
     <div class="row">
       <div class="col-md-2">{{ key }}</div>
       <div class="col-md-6">{{ release[key] }}</div>
@@ -19,7 +19,10 @@
   {% if release['author'] is not none %}
   <div class="row">
     <div class="col-md-2">author</div>
-    <div class="col-md-6">{{ release['author']['name'] }} - {{ release['author']['email'] }}</div>
+    <div class="col-md-6">
+      {{ release['author']['name'] }} - {{ release['author']['email'] }}
+      {% if 'decoding_failures' in release['author'] %}(some decoding errors){% endif %}
+    </div>
   </div>
   {% endif %}
   </div>
@@ -29,6 +32,11 @@
     <div class="col-md-6"><a href="{{ release['target_url'] }}">{{ release['target_url'] }}</a></div>
   </div>
   {% endif %}
+  {% if 'decoding_failures' in release %}
+  <div class="row">
+    <div class="col-md-10">(some decoding errors)</div>
+  </div>
+  {% endif %}
 </div>
 {% endif %}
 
diff --git a/swh/web/ui/templates/revision-directory.html b/swh/web/ui/templates/revision-directory.html
--- a/swh/web/ui/templates/revision-directory.html
+++ b/swh/web/ui/templates/revision-directory.html
@@ -13,10 +13,20 @@
         {% if result['content'] is not none %}
             {% for e in result['content'] %}
               {% if e.type == 'dir' %}
-              <div><p><a class="link{{e.type}}" href="{{e.dir_url}}">{{ e.name }}</a></p></div>
+		<div>
+		  <p>
+		    <a class="link{{e.type}}" href="{{e.dir_url}}">{{ e.name }}</a>
+		    {% if 'decoding_failures' in e %}(some decoding errors){% endif %}
+		  </p>
+		</div>
               {% else %}
-              <div><p><a class="link{{e.type}}" href="{{e.file_url}}">{{ e.name }}</a></p></div>
-              {% endif %}
+		<div>
+		  <p>
+		    <a class="link{{e.type}}" href="{{e.file_url}}">{{ e.name }}</a>
+    		    {% if 'decoding_failures' in e %}(some decoding errors){% endif %}
+		  </p>
+		</div>
+            {% endif %}
             {% endfor %}
         {% endif %}
     {% else %}
@@ -39,7 +49,12 @@
            <div class="col-md-2">data</div>
            <div class="col-md-10"><pre>{{ result['content']['data'] }}</pre></div>
         </div>
-        {% endif %}
+      {% endif %}
+      {% if 'decoding_failures' in result %}
+	<div class="row">
+	  <div class="col-md-10">(some decoding errors)</div>
+	</div>
+      {% endif %}
     {% endif %}
 {% endif %}
 {% endblock %}
diff --git a/swh/web/ui/templates/revision-log.html b/swh/web/ui/templates/revision-log.html
--- a/swh/web/ui/templates/revision-log.html
+++ b/swh/web/ui/templates/revision-log.html
@@ -49,7 +49,12 @@
     {% if revision['author'] is not none %}
            <div class="row">
               <div class="col-md-2">Author</div>
-              <div class="col-md-6"><p><a href="{{ revision['author_url'] }}">{{ revision['author']['name'] }}</a></p></div>
+              <div class="col-md-6">
+		<p>
+		  <a href="{{ revision['author_url'] }}">{{ revision['author']['name'] }}</a>
+		  {% if 'decoding_failures' in revision['author'] %}(some decoding errors){% endif %}
+		</p>
+	      </div>
            </div>
            <div class="row">
               <div class="col-md-2">Date</div>
@@ -60,7 +65,12 @@
     {% if revision['committer'] is not none %}
            <div class="row">
               <div class="col-md-2">Committer</div>
-              <div class="col-md-6"><p><a href="{{ revision['committer_url'] }}">{{ revision['committer']['name'] }}</a></p></div>
+              <div class="col-md-6">
+		<p>
+		  <a href="{{ revision['committer_url'] }}">{{ revision['committer']['name'] }}</a>
+		  {% if 'decoding_failures' in revision['committer'] %}(some decoding errors){% endif %}
+		</p>
+	      </div>
            </div>
            <div class="row">
               <div class="col-md-2">Committer Date</div>
@@ -86,14 +96,13 @@
     {% endif %}	    
 	    
     {% for key in revision.keys() %}
-           {% if key in ['type', 'synthetic'] and revision[key] is not none %}
+           {% if key in ['type', 'synthetic'] and key not in ['decoding_failures'] and revision[key] is not none %}
             <div class="row">
               <div class="col-md-2">{{ key }}</div>
               <div class="col-md-6"><p>{{ revision[key] }}</pre></div>
             </div>
            {% endif %}
     {% endfor %}
-
     {% for key in ['parent_urls', 'children_urls'] %}
         {% if revision[key] is not none %}
          <div class="row">
@@ -104,6 +113,12 @@
          </div>
         {% endif %}
     {% endfor %}
+	 {% if 'decoding_failures' in revision %}
+	 <div class="row">
+	   <div class="col-md-10">(some decoding errors occurred)</div>
+	 </div>
+	 {% endif %}
+
   </div>
   <hr />
   {% endfor %}
diff --git a/swh/web/ui/templates/revision.html b/swh/web/ui/templates/revision.html
--- a/swh/web/ui/templates/revision.html
+++ b/swh/web/ui/templates/revision.html
@@ -32,7 +32,12 @@
     {% if revision['author'] is not none %}
            <div class="row">
               <div class="col-md-2">Author</div>
-              <div class="col-md-6"><p><a href="{{ revision['author_url'] }}">{{ revision['author']['name'] }}</a></p></div>
+              <div class="col-md-6">
+		<p>
+		  <a href="{{ revision['author_url'] }}">{{ revision['author']['name'] }}</a>
+		  {% if 'decoding_failures' in revision['author'] %}(some decoding failed){% endif %}
+		</p>
+	      </div>
            </div>
            <div class="row">
               <div class="col-md-2">Date</div>
@@ -43,7 +48,12 @@
     {% if revision['committer'] is not none %}
            <div class="row">
               <div class="col-md-2">Committer</div>
-              <div class="col-md-6"><p><a href="{{ revision['committer_url'] }}">{{ revision['committer']['name'] }}</a></p></div>
+              <div class="col-md-6">
+		<p>
+		  <a href="{{ revision['committer_url'] }}">{{ revision['committer']['name'] }}</a>
+		  {% if 'decoding_failures' in revision['committer'] %}(some decoding failed){% endif %}
+		</p>
+	      </div>
            </div>
            <div class="row">
               <div class="col-md-2">Committer Date</div>
@@ -87,6 +97,11 @@
          </div>
         {% endif %}
     {% endfor %}
+    {% if 'decoding_failures' in revision %}
+    <div class="row">
+      <div class="col-md-10">(some decoding failed)</div>
+    </div>
+    {% endif %}
 
 </div>
 {% endif %}
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 +100,33 @@
         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',
+            'decoding_failures': ['c', 'd']
+        }
+
+        actual_output = converters.from_swh(some_input,
+                                            hashess={'a', 'b'},
+                                            bytess={'c', 'd'})
+        for v in ['a', 'b', 'c', 'd']:
+            self.assertEqual(expected_output[v], actual_output[v])
+        self.assertEqual(len(expected_output['decoding_failures']),
+                         len(actual_output['decoding_failures']))
+        for v in expected_output['decoding_failures']:
+            self.assertTrue(v in actual_output['decoding_failures'])
+
+    @istest
     def from_swh_empty(self):
         # when
         self.assertEquals({}, converters.from_swh({}))