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JSON Diff & Compare

Compare two JSON objects and see exactly what was added, removed, or changed — by key path, including nested objects and arrays. Free.

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💡 How to use

  • Paste two JSON objects and click Compare to see exactly what was added, removed, or changed.
  • Differences are shown by key path (e.g. tags[1]) so nested changes are easy to locate.
  • Runs entirely in your browser — nothing is uploaded.

Free JSON Diff & Compare Tool

Compare two JSON objects and see exactly what changed. Paste an original and a modified JSON to get a clear list of added, removed, and changed values — each shown by its key path so nested differences are easy to find. Free, no sign-up, and nothing is uploaded.

What this tool does

When two JSON documents look almost identical, spotting the real difference by eye is slow and error-prone. This tool parses both, walks them key by key, and reports precisely what was added, removed, or changed — including inside nested objects and arrays — so you can review changes in seconds instead of scrolling back and forth.

How to use it

It is instant:

  • Paste the original JSON on the left and the changed JSON on the right.
  • Click Compare.
  • Read the color-coded results: green for added, red for removed, amber for changed.
  • Copy the diff summary to share or save.

How differences are shown

Each difference is labelled with the exact path to the value, using dot notation for object keys and brackets for array positions — for example <code>server.port</code> or <code>tags[1]</code>. Changed values show the old and new value side by side (old → new), so you can see not just that something changed but what it changed from and to.

Structural vs value changes

The tool distinguishes between a value that changed (same key, different content), a key that was added in the new document, and a key that was removed. It also compares arrays position by position and detects when a value's type changes — for example a number becoming a string — which is a common source of bugs in APIs and configuration.

Common uses

Developers use a JSON diff to review API responses before and after a change, to compare configuration between environments (staging vs production), to debug why two requests behave differently, and to verify that a transformation or migration produced the expected output. It is also handy in code review when a JSON fixture changes.

Privacy

Both JSON documents are parsed and compared entirely in your browser — nothing is uploaded, logged, or stored. That makes it safe for comparing real API payloads, config files, and other data you would not want to send to an external server.

FAQ

Is this JSON diff tool free?
Yes. It is completely free, runs in your browser, and needs no account or sign-up.
Is my JSON uploaded anywhere?
No. Both documents are parsed and compared locally in your browser, so your data never leaves your device.
How are nested differences shown?
Each change is labelled with its full key path, using dots for object keys and brackets for array indexes, so you can locate nested differences immediately.
Does it compare arrays?
Yes. Arrays are compared position by position, and items added to or removed from the end are reported clearly.
Does the order of object keys matter?
No. Objects are compared by key, so reordering keys does not count as a difference. Array order does matter, since arrays are ordered.
What if my JSON is invalid?
The tool reports which side has invalid JSON and shows the parser error, so you can fix it before comparing.
Can I copy the results?
Yes. Click Copy diff to copy a plain-text summary of every added, removed, and changed value.

Related tools

Pro tip: pair this tool with Upside Down Text Generator and What is My Browser for a faster SEO workflow.