JSON Diff

Runs in browser

Compare two JSON objects and see added, removed, and changed keys.

Compare two JSON objects and see exactly what changed. Highlights added, removed, and modified keys with a side-by-side diff view. Runs entirely in your browser.

JSON Diff tool

+1−1~21 unchanged
Key
LeftRight
~
age
3031
+
city
—"New York"
−
email
"[email protected]"—
~
role
"admin""user"

🔒 Runs in your browser · No uploads · Your data never leaves your device

How to use

  1. Paste left JSON

    Enter the original JSON object in the left panel.

  2. Paste right JSON

    Enter the new or updated JSON in the right panel.

  3. Review the diff

    Green = added, red = removed, yellow = changed value. Toggle 'Show unchanged' to see all keys.

Common use cases

  • Comparing API response versions — Diff two JSON API responses to identify exactly what changed between API versions or deployments.
  • Reviewing config file changes — Compare JSON config files from different environments to spot differences in settings.
  • Debugging data transformation pipelines — Compare input and output JSON from a transformation step to verify that only expected changes were made.

Examples

  • User update

    Two user objects where age and role changed.

    Output
    ~ age: 30 → 31, ~ role: admin → user, + city: New York, − email: (removed)

Frequently asked questions

Does this support nested JSON?
Yes. Keys are flattened using dot notation (e.g. address.city) for deep comparison.
Is my JSON sent anywhere?
No. The diff runs entirely in your browser with no data leaving your device.

Key concepts

Structural diff
A comparison of two data structures that identifies added, removed, and changed keys regardless of key ordering.

Related tools

You might find these useful too.

Related Guides

→ Json Deep Merge Example