JSON Diff Checker

Compare two JSON files online and see every added, removed or changed value — free JSON diff.

About

About the JSON Diff Checker

Compares two JSON documents structurally and lists every path where a value was added, removed or changed.

Backend developers use it to see exactly what changed between two versions of an API response or config file, and QA engineers use it to confirm an expected JSON payload matches an actual one down to the field. It's one of many free data tools on Toolapt, and like every tool here, it's free to use with no sign-up and no limit on how many times you run it.

Choose what to view about this tool

Guide

Using the JSON Diff Checker

  1. 1

    Step 1

    Paste the original JSON into the Original JSON box.

  2. 2

    Step 2

    Paste the changed JSON into the Changed JSON box.

  3. 3

    Step 3

    Click "Compare".

  4. 4

    Step 4

    Read the table of differences, showing each path's original and changed value.

  • Compares two JSON documents recursively, key by key and value by value
  • Reports the exact dot-notation path of every difference, like user.address.city
  • Distinguishes between a changed value, a missing key, and an added key
  • Ignores key order — only the actual structure and values are compared
  • Clear message when the two documents are structurally identical
  • Works entirely in your browser — nothing you paste is sent to a server
  • Free to use, with no sign-up and no limit on how many times you run it

Backend developers

Backend developers use the JSON Diff Checker for seeing exactly what changed between two versions of an API response or configuration file.

QA engineers

QA engineers use the JSON Diff Checker for confirming an actual API response matches an expected fixture down to the individual field.

Frontend developers

Frontend developers use the JSON Diff Checker for tracking down which field changed after a backend update broke their UI.

Data engineers

Data engineers use the JSON Diff Checker for spotting schema drift between two snapshots of the same data source.

Examples

JSON Diff Checker examples

4 worked examples

01

Version bump in a config

Compare {"name":"toolapt","version":"1.2.0"} against the same object with "1.3.0" to get 1 change reported: version changed from "1.2.0" to "1.3.0".

02

Added field in an API response

Compare {"id":1,"name":"Alice"} against {"id":1,"name":"Alice","role":"admin"} to get 1 addition: role went from (missing) to "admin".

03

Removed key between snapshots

Compare {"id":1,"email":"a@x.com"} against {"id":1} to get 1 removal: email went from "a@x.com" to (missing).

04

Same data, different key order

Compare {"a":1,"b":2} against {"b":2,"a":1} and the tool reports "The two documents are structurally identical.", since key order is ignored.

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FAQ

Frequently asked questions

Quick answers to common questions about the JSON Diff Checker.

What does the JSON Diff Checker do?

It compares two JSON documents and lists every path where a value was added, removed or changed.

Is the JSON Diff Checker free to use?

Yes. It's free, with no sign-up, no watermark and no limit on how many times you use it.

Is my JSON safe when I use this tool?

Yes. The comparison runs entirely on your own device — nothing you paste is sent to a server.

Does key order matter?

No. The comparison is structural, so two objects with the same keys and values in a different order are treated as identical.

What does a path like user.tags.1 mean in the results?

It's a dot-notation path showing exactly where the difference is — in this example, inside the user object's tags array, at index 1.

What happens if a key exists in one document but not the other?

It's reported as (missing) on whichever side doesn't have it, alongside the value from the side that does.

What if my JSON doesn't parse?

The tool tells you which of the two documents is invalid and includes the underlying parser's error message.

Can I use the JSON Diff Checker on my phone?

Yes. The page is fully responsive and works on mobile, tablet and desktop browsers alike.

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