Private: nothing leaves your browser. No sign-up.
JSON Diff Checker
Spot every difference between two JSON documents. Free, no sign-up, fully private.
What it does
Paste the old JSON on the left and the new JSON on the right, then compare. The tool flattens nested objects into dotted key paths and lists every added, removed, or changed value in a color-coded table with a summary count.
Common uses
Checking what an API response changed between versions, reviewing config edits before deploy, or spotting accidental edits in a JSON file.
Private by design
Parsing and comparison happen locally in JavaScript. Nothing you paste ever leaves your device.
Planning estimate only. Results use the list prices shown and may differ from your actual bill. Terms
Frequently asked questions
Does it handle nested objects?
Yes. Nested keys are flattened to dotted paths like address.city, so deep changes are easy to spot.
What about arrays?
Arrays are summarized by length (for example [array:3]) rather than compared element by element.
Is my JSON sent to a server?
No. Everything happens in your browser.