Additions
See keys and array items that were added on the changed side, highlighted in green.
JSON Diff
JSON Diff: Compare Two JSON Files Online
Paste two JSON documents and instantly see a structural diff: added, removed, and changed keys and values, with a running count of every difference.
- Added, removed and changed, line by line
- Big numbers and key order kept exact
- Runs in your browser
Quick modeAutosaves in this browser
How it reads
Every change, colour-coded.
Removals
Spot anything dropped from the original, marked clearly so nothing slips by.
Changes
Value changes show old → new inline, with a running count of every difference.
Compare JSON documents without leaving the browser
Paste two JSON documents and instantly see a structural diff: added, removed, and changed keys and values, with a running count of every difference.
Why use it
Why use this JSON diff checker
See added, removed, and changed values colour-coded at a glance.
Compare structurally — key order doesn't create false differences.
Get a running count of additions, removals, and changes.
Keep payloads local — nothing is uploaded to a server.
How it works
How to compare two JSON files
- 1
Paste the original JSON on the left and the changed JSON on the right.
- 2
Read the colour-coded diff, with old → new shown inline for changes.
- 3
Use the summary counts to confirm exactly what changed.
Use cases
JSON diff use cases
- Diff an API response before and after a change.
- Compare two config files to spot drift.
- Review what a transformation added or removed.
- Verify a fixture matches an expected payload.
FAQ
JSON diff questions
Are my JSON files uploaded?
No. The comparison runs entirely in your browser — nothing is sent to a server.
How are objects and arrays compared?
Objects are compared by key (order-independent), and arrays are compared by index.
What counts as a change?
A key present on only one side is added or removed; a key on both sides with a different value is a change (shown old → new).
Does key order matter?
No. Reordering object keys does not produce a difference, since objects compare by key.