JSON Diff Online

Compare two JSON objects and highlight every addition, removal, and value change.

A JSON Diff tool is a free online utility that compares two JSON files side-by-side and highlights every addition, removal, and changed value — running entirely in your browser with no data uploaded.

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4.8· 743 ratings

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Added Removed Changed

JSON A (Original)

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JSON B (Modified)

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What is JSON Diff?

A JSON diff tool compares two JSON documents and surfaces every structural difference — keys added, keys removed, and values that changed. Instead of reading two files line-by-line, the diff engine walks both object trees simultaneously and reports discrepancies at the exact key path.

This tool runs 100% in your browser. No JSON is sent to a server. Use our JSON syntax validator to check each file for errors before comparing.

Common Use Cases

check_circleCompare API responses before and after a code change
check_circleVerify configuration diffs between staging and production
check_circleReview JSON data migrations for unexpected field changes
check_circleDebug webhook payloads that differ from expected schema
check_circleTrack changes in JSON fixtures between test runs
check_circleValidate JSON exports from different data sources

JSON Diff Example

Given two JSON objects, the diff tool identifies exactly what changed:

JSON A (Original)

{
  "name": "John",
  "age": 30
}

JSON B (Modified)

{
  "name": "Jane",
  "age": 31,
  "city": "NYC"
}

CHANGED name: "John" → "Jane"

CHANGED age: 30 → 31

ADDED city: "NYC"

Related JSON Tools

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JSON Formatter

Beautify and pretty-print JSON with configurable indentation.

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JSON Validator

Validate JSON syntax and get error location before comparing.

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JSON Compare

Side-by-side comparison with line-level diff highlighting.

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JSON Viewer

Browse JSON structure in a collapsible tree layout.

FAQs

What is the difference between JSON diff and JSON compare?expand_more

They refer to the same operation. A diff shows the structural delta — what changed, what was added, what was removed — between two JSON documents. "Compare" is a synonym used interchangeably.

Can I diff large JSON files?expand_more

Yes. Processing is entirely client-side so there is no server size limit. Performance depends on your browser and device — files up to several MB diff in milliseconds on modern hardware.

Does the tool handle nested JSON?expand_more

Yes. The diff engine recursively walks nested objects and arrays, reporting the full key path (e.g. user.address.city) for every difference found at any depth.

Is my JSON data safe to paste here?expand_more

Completely. No data is sent to any server. All processing happens in your browser using JavaScript. You can verify this by disconnecting from the internet — the tool still works offline.