Hoboleaks is a lightweight* comparison website for both TQ & SISI patches. New patches are checked for every 10 minutes. You can also see what changed in specific revisions (currently I only display the last 10). Navigate through the pages by using the menu at the top of the site. The website will automatically update within a few minutes of each patch (usually), and you may need to do a cache-less refresh (CTRL+F5) to see changes immediately when that happens.
Tip: Alt-click an element to select it. You can then send the link in your address bar to someone and those same elements will be selected for them as well. Useful for highlighting particular changes when sharing!
I have only verified the basic functionality of the website in Chrome or Firefox. If you use a different browser, don't worry, it's pretty shit on Chrome & Firefox as well. If you use Internet Explorer, I doubt anything will work, but you should be used to that.
* Lacking in both features and aesthetics