Original
-2drop a .json file
Modified
+3drop a .json file
+3 additions-2 deletions
11 {
22 "id": 1,
33 "name": "Alice Martin",
4- "role": "admin",
5- "active": true
4+ "role": "editor",
5+ "active": true,
6+ "age": 30
67 }

Why compare JSON rather than raw text

A plain text diff treats {"b":2,"a":1} and {"a":1,"b":2} as different, but they're the same JSON object. A JSON-aware diff normalises key order and data types before comparing.

You see only semantic differences: a field that changed value, a key that was added, an array element that was removed — no noise from formatting or key reordering.

Reading the diff output

The counters in each panel header tell you at a glance how many additions and removals there are. Paste the two JSON documents and the diff updates immediately.

RemovedError tone — appears only in the left document
AddedValid tone — appears only in the right document
UnchangedNeutral color

Debugging and review use cases

Developers compare API responses across environments to catch configuration drift between staging and production. QA engineers diff before/after snapshots of database records to verify a migration.

Backend teams review the delta between two versions of a config file before deployment. Because both documents stay in your browser, you can paste sensitive payloads without concern.