JSON Compare (JSON Diff)

Comparing JSON as plain text produces noise: a reordered key or different indentation shows up as a change even when the data is identical. This tool compares the parsed structure instead. Key order is ignored, every difference is listed with its path, and options cover the usual false alarms — rounding in numbers, letter case, and arrays whose items moved.

How to use this tool

1. Paste the original JSON on the left and the changed version on the right.
2. If your arrays hold records with an id, choose Match objects by a key field and enter the field name.
3. Optionally set a number tolerance or ignore case in strings.
4. Read the table of paths and changes; the line diff below shows the same data as text.

Formula

diff(L, R): different types → type change; objects → compare shared keys, list left-only keys as removed and right-only keys as added; arrays → by position or by key; numbers equal if |L − R| ≤ tolerance

Paths use the same notation as JavaScript and JSONPath: $.stock.store, $.tags[2], and $.items[id=7] for an item matched by key. The line diff sorts keys first so that key order does not create false differences.

Example

For the sample lamp, the tool finds 5 differences: $.name changed ("Desk lamp" → "Desk Lamp"), $.price changed (34.9 → 29.9), $.tags[2] added ("sale"), $.stock.store removed and $.color added. Ticking ignore case removes the name change and leaves 4.