diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..2d30933
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1 @@
+*.png diff=image
diff --git a/README.md b/README.md
index 1fd5249..52c7d21 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,13 @@
 A repository for golden image files that are used by tests in https://github.com/flutter/flutter.
 
 See: https://github.com/flutter/flutter/wiki/Writing-a-golden-file-test-for-package%3Aflutter
+
+## Getting diffs for golden images
+
+If you have ImageMagick and you want to use it to show diffs of files
+in this repo, add the following to your `~/.gitconfig`:
+
+```
+[diff "image"]
+    command = /path/to/this/repo/diff-images.sh
+```
diff --git a/diff-images.sh b/diff-images.sh
new file mode 100755
index 0000000..24135da
--- /dev/null
+++ b/diff-images.sh
@@ -0,0 +1,2 @@
+#!/bin/sh
+compare $2 $1 png:- | montage -geometry +4+4 $2 - $1 png:- | display -title "$1" -