diff -r f1f707dd7cae Doc/library/imghdr.rst
--- a/Doc/library/imghdr.rst	Wed Jan 08 16:01:42 2014 +0100
+++ b/Doc/library/imghdr.rst	Wed Jan 08 13:27:25 2014 -0800
@@ -48,6 +48,8 @@
 +------------+-----------------------------------+
 | ``'png'``  | Portable Network Graphics         |
 +------------+-----------------------------------+
+| ``'webp'`` | WebP files                        |
++------------+-----------------------------------+
 
 You can extend the list of file types :mod:`imghdr` can recognize by appending
 to this variable:
diff -r f1f707dd7cae Lib/imghdr.py
--- a/Lib/imghdr.py	Wed Jan 08 16:01:42 2014 +0100
+++ b/Lib/imghdr.py	Wed Jan 08 13:27:25 2014 -0800
@@ -112,6 +112,12 @@
 
 tests.append(test_bmp)
 
+def test_webp(h, f):
+    if h.startswith(b'RIFF') and h[8:12] == b'WEBP':
+        return 'webp'
+
+tests.append(test_webp)
+
 #--------------------#
 # Small test program #
 #--------------------#