JSON compare

Client

Paste two JSON documents and compare structure and values. A small example is pre-filled so you can try Compare immediately.

Learn more: comparing structured data

Compare two JSON values side by side to see what changed—useful for config diffs, API responses, or before/after debugging.

Structural diff

Unlike plain text diff, JSON compare can align objects and arrays by structure, so you spot added or removed fields and changed values without noise from whitespace alone.

When to use it

Typical uses include reviewing migrations, verifying that two environments return the same shape of data, and narrowing down a bug to a single field.

Two JSON inputs

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Compare parses both sides with JSON.parse and walks values recursively. Objects and arrays are ordered by keys / indices; missing keys or length mismatches are reported as paths under $.

After Compare, both sides are pretty-printed; lines that differ in the formatted text are highlighted in each editor. Paths below list semantic differences (JSON structure). Editing a panel clears highlights.

All processing stays in your browser. Very large documents may be slow.

Both sides load a sample by default—click Compare to format, list paths, and highlight differing lines.

Common use cases

  • Review config or API diffs when only JSON structure matters—array order and nested keys surface as paths.
  • Sanity-check two exports from the same service after a version bump.
  • Compare normalized parses after formatting messy payloads on both sides.

Common mistakes to avoid

  • Expecting text diff semantics

    This tool compares parsed values. Whitespace and key order may differ while the structure matches—use the path list to understand what changed.

FAQ

Is my JSON sent to Toolcore?

No. Both documents are parsed and compared locally in your browser.

More tools

Related utilities you can open in another tab—mostly client-side.