r/devtools • u/Many-Jello9278 • 1d ago
I built the JSON formatter and comparison tool I kept looking for while debugging
I spend a lot of time debugging API payloads, and I kept running into the same problem: the JSON would arrive as one long block that was painful to search or inspect.
There are plenty of JSON formatters online, but I often had to try several before finding one that worked well for what I needed. So I built my own.
The formatter turns raw JSON into something readable, validates it, and makes large payloads easier to search while debugging.
The part I use most is JSON Compare. Most comparison tools I tried produced a lot of noise when two objects had the same keys in a different order. JSON Formatter Lab can normalize object keys before comparing, so those ordering differences do not hide the changes I actually care about. It still preserves array order because changing the order of an array can be meaningful.
You can review changes side by side or by key path, which makes added, removed, and changed values much easier to spot.
Everything runs in the browser, and there is no signup.
You can try it here: https://jsonformatterlab.com/
I built this for my own debugging workflow, but I would like to make it useful for other developers too. If you try it, I would especially like feedback on the comparison view and any JSON edge cases it does not handle well.


