Developer Tool

JSON Compare

Compare two JSON files or snippets side by side and spot changed values, missing keys, added fields, and type mismatches. Everything runs privately in your browser.

No uploadsStructural diffFree & no signup

Left JSON10 lines

Right JSON10 lines

How to compare JSON online

Use JSON Compare to turn two raw JSON documents into a readable path-by-path diff.

01
Paste your original JSON
Add the baseline JSON on the left. This can be an API response, config file, package data, or any valid JSON value.
02
Paste the updated JSON
Add the second JSON on the right. Use Format both if you want both inputs normalized before comparing.
03
Compare and review differences
Click Compare JSON to see added fields, removed fields, changed values, and type mismatches with exact JSON paths.
04
Copy or download the report
Save the structured diff report as JSON or copy it into a pull request, bug ticket, or release note.

What people use it for

JSON diffing is useful whenever structured data changes and you need a precise explanation of what moved.

API response testing

Compare old and new API payloads to catch changed fields, missing keys, or unexpected data types before release.

Config file review

Check environment, app, and build configuration changes without scanning large JSON files by hand.

Data migration checks

Validate exported records before and after a migration to confirm important values survived the move.

Package and lockfile inspection

Review dependency metadata, script changes, or generated JSON output in a cleaner, path-based format.

Webhook debugging

Compare webhook payloads from different events, providers, or environments to understand what changed.

QA and bug reports

Attach a concise JSON diff report to tickets so developers can jump straight to the changed paths.

Frequently asked questions

Yes. JSON Compare is free to use with no signup, no usage limits, and no watermarks.

No. The comparison runs locally in your browser, so your JSON is not uploaded or stored by Toolminex.

You can compare any valid JSON value, including objects, arrays, strings, numbers, booleans, and null values.

No. JSON object keys are compared by name, so the same keys in a different order are treated as equal.

Yes. Arrays are compared by index because order usually matters in API responses, configuration lists, and exported data.

It detects added paths, removed paths, changed primitive values, and type changes such as a string becoming a number.

Yes, but very large files depend on your device and browser memory. For huge JSON exports, comparing smaller sections is usually faster.

Yes. You can copy the report or download it as a JSON file for tickets, code reviews, or release documentation.

Yes. The tool works on mobile browsers, though comparing large JSON documents is more comfortable on a desktop screen.

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How to compare JSON online

Use JSON Compare to turn two raw JSON documents into a readable path-by-path diff.

Paste your original JSON

Add the baseline JSON on the left. This can be an API response, config file, package data, or any valid JSON value.

Paste the updated JSON

Add the second JSON on the right. Use Format both if you want both inputs normalized before comparing.

Compare and review differences

Click Compare JSON to see added fields, removed fields, changed values, and type mismatches with exact JSON paths.

Copy or download the report

Save the structured diff report as JSON or copy it into a pull request, bug ticket, or release note.