DataFmt

JSON Diff

List added, removed and changed fields across two JSON documents, organised by path.

Drag & drop a file here, or click to upload

About this tool

Reviewing API contract changes, comparing configuration snapshots and verifying upgrades all need precise JSON comparison. A plain text diff cannot tell that reordering keys is semantically identical, or that a value type has changed.

Our JSON Diff uses microdiff for a deep structural comparison and organises the result by JSON Path, colour-coded for CREATE / REMOVE / CHANGE operations, with expandable old and new values.

How to use

  1. Paste the "old" JSON on the left and the "new" JSON on the right.
  2. Click "Compare".
  3. Browse the list of differences grouped by path.
  4. Expand any entry to see old and new values.

Use cases

Notes

Frequently Asked Questions

Is the output a line-based diff?
No. It is a path-based change list, which is more meaningful across indentation changes.
What if the two documents have different shapes?
Fields present only on one side are reported as additions or removals.
Are reordered array elements flagged as diffs?
Yes. Sort arrays first if you need content-based comparison.