JSON Compare

Compare two JSON documents — ignores key order, lists every changed path, merge side by side

JSON Compare finds the real differences between two JSON documents. Both sides are validated and normalised — keys sorted, and optionally arrays too — so formatting and key order never show up as changes. You get an aligned side-by-side diff you can merge, plus a table of every changed path with its old and new value.

How to use JSON Compare

  1. Add two JSON documents. Paste or open JSON on the left and right.
  2. Choose options. Keep Sort keys on, and turn on Ignore array order if order does not matter.
  3. Compare. Press Compare to validate, normalise and diff both documents.
  4. Review. Read the structural changes table and merge differences as needed.

Features

  • Offline Processing: Computes operations instantly in your local browser client.
  • One-Click Copy: Instantly copy inputs or outputs to your clipboard.
  • Precision Outputs: Processes inputs immediately to provide clean, error-free results.

Why use this tool

  • Only meaningful changes: key order and whitespace are ignored automatically.
  • Path-level report: see exactly which fields were added, removed or changed type.
  • Merge and export: resolve each difference and download the merged JSON.

Frequently asked questions

How do I compare two JSON files online?

Paste or open one JSON document on each side and press Compare. Both are validated, formatted the same way and compared side by side, with changed values highlighted. A table below lists every path that was added, removed or changed, such as owner.email or features[3].

Does key order matter when comparing JSON?

Not with Sort keys turned on, which is the default. Object keys are sorted alphabetically on both sides before comparing, so {"a":1,"b":2} and {"b":2,"a":1} are reported as equal. Turn it off if you need to see key order changes too.

Can I ignore the order of items in an array?

Yes. Turn on Ignore array order and array items are sorted before comparing, so the same items in a different order are treated as equal. Leave it off when order is meaningful, for example in a list of steps or a sorted result set.

What does type changed mean in the results?

It means the value at that path changed kind, not just value, for example from the boolean true to the string "true", or from a number to null. These are easy to miss by eye but often break code that reads the JSON, so they are listed separately.

Can I merge two JSON documents?

Yes. Step through the differences and keep the left version, the right version or both for each change, with undo and reset. When you are done, copy or download either side. Check the merged file with the JSON Formatter if you kept both versions of a block.

What happens if one of the JSON documents is invalid?

The comparison stops and tells you which side is invalid and the line and column of the problem, such as a trailing comma or a missing quote. Fix it in the editor and press Compare again. Nothing is uploaded; parsing happens in your browser.

Is my data shared when using the JSON Compare?

No. Toolskyt operates under a zero-server policy. All calculations, data formatting, and file exports are executed locally on your machine.

Do I need to sign up or pay to use the JSON Compare?

No, this tool is 100% free. There are no limits, sign-ups, subscriptions, or hidden charges required.

Is it safe to paste API tokens or private JSON data here?

Yes, absolutely. The tool executes 100% inside your local browser memory space. No inputs are sent to any servers.

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