JSON Diff Checker
Compare two JSON documents structurally and see exactly what was added, removed or changed, with the full path to every difference.
About the JSON Diff Checker
This JSON diff checker compares two JSON documents key by key and reports precisely what changed: values added, values removed, and values whose content differs — each with the exact path (like user.address.city or items[2].price) so you can find it instantly. Key order and formatting are ignored, so only real structural differences are flagged.
It's built for the everyday tasks where eyeballing two blobs of JSON fails: diffing API responses before and after a change, checking config files across environments, reviewing what a script modified, or confirming two exports are equivalent.
Both documents are parsed and compared entirely in your browser — nothing is uploaded — so it's safe for production payloads containing tokens or personal data.
How to Use the JSON Diff Checker
- 1Paste the original JSON on the left and the updated JSON on the right.
- 2Click Compare to run a deep structural diff.
- 3Review added, removed and changed entries, each with its full path.
- 4Fix your data or copy the diff summary.
Frequently Asked Questions
How does the diff decide what changed?
It walks both documents recursively. A path present only in the second document is 'added'; one present only in the first is 'removed'; a path in both but with different values is 'changed', showing old and new. Objects and arrays are compared by their contents, not by formatting or key order.
Does key order or whitespace matter?
No. Both documents are parsed into data structures first, so indentation, line breaks and the order of object keys are irrelevant — {"a":1,"b":2} and {"b":2,"a":1} are equal. Only genuine differences in keys and values are reported.
How are array differences handled?
Arrays are compared by index, so items[0], items[1] and so on are matched position by position. Inserting an element near the start can therefore mark several later positions as changed, since everything shifts. For value data this index-based comparison is usually what you want.
Is my JSON sent to a server?
No. Parsing and comparison run entirely in JavaScript in your browser. Neither document is transmitted or stored, so you can safely diff API responses, config files and other data containing secrets.
What if one side isn't valid JSON?
The tool validates both inputs before comparing and shows a clear parse error — including a hint about where the problem is — so you can fix the malformed side first. Both documents must be valid JSON for the diff to run.