diff --git a/1.4-Troubleshooting.md b/1.4-Troubleshooting.md
index f32811a..5c8815a 100644
--- a/1.4-Troubleshooting.md
+++ b/1.4-Troubleshooting.md
@@ -1,5 +1,10 @@
 Besides asking and guessing, the only way to find the cause(s) of why something doesn't work as expected, is to **methodically** eliminate preferences. And only after it is confirmed that the user.js is the cause, by replicating the problem in a new profile with no extensions.
 
+### :small_blue_diamond: Compare multiple user.js files
+
+If you want to precisely compare your version against the template, or even your version against someone else's, there is [Firefox-User.JS-Tool](https://github.com/icpantsparti/firefox-user.js-tool) for this!  
+A live demo can be found [here](https://icpantsparti.github.io/firefox-user.js-tool/userjs-tool.html).
+
 ### :small_blue_diamond: Did an extension break?
 
 You may open [a new issue](https://github.com/HorlogeSkynet/thunderbird-user.js/issues/new), and we will try to help you debug this.