DeveloperKit

JSON Compare & Diff

Compare two JSON documents and see exactly what changed. Free, instant, and 100% in your browser.

Original JSON

Modified JSON

Differences

Paste JSON into both editors to see the differences.

What is a JSON Compare Tool?

A JSON compare tool, also called a JSON diff tool, finds the differences between two JSON documents. It is useful for comparing API responses before and after a change, reviewing configuration updates, debugging test fixtures, and checking data migrations.

A plain text diff reports formatting noise, such as indentation or reordered keys. The DeveloperKit JSON Compare tool normalizes both documents first, so it only shows meaningful changes to the data.

Features

  • Side-by-side and unified views

    See both documents aligned line by line, or switch to a compact unified view with + and − markers.

  • Structural changes list

    Every added, removed, and changed value is listed with its exact JSON path, such as $.owner.email.

  • Ignores formatting and key order

    Whitespace never counts as a change, and key order can be ignored, so you only see real data differences.

  • Live validation

    Both inputs are validated as you type, with the exact line and column of any syntax error.

  • Private by design

    Both documents are compared locally in your browser. Nothing is uploaded or stored.

  • Handles large files

    Long unchanged sections are collapsed, so large documents with a few changes stay fast and readable.

How to Compare JSON Online

  1. Paste or upload the original JSON into the left editor.
  2. Paste or upload the modified JSON into the right editor.
  3. Review the highlighted differences in the side-by-side or unified view.
  4. Open the Changes list to see every difference with its JSON path.

Frequently Asked Questions

How do I compare two JSON files?

Paste or upload the original JSON on the left and the modified JSON on the right. The differences appear instantly below, highlighted in red for removed content and green for added content.

Does key order matter when comparing JSON?

In JSON, objects are unordered, so {"a":1,"b":2} and {"b":2,"a":1} contain the same data. With Ignore key order enabled (the default), these documents are treated as identical. Turn it off to see key order changes in the line views.

How are arrays compared?

Arrays are ordered, so in the Changes list they are compared position by position. The side-by-side and unified views use a line-based diff that also detects inserted and removed items in the middle of an array.

Is it safe to compare sensitive JSON here?

Yes. The comparison runs entirely in your browser. Your JSON is never sent to a server, logged, or stored.

What does a path like $.users[0].email mean?

It is a JSONPath expression. $ is the root of the document, .users selects the users property, [0] selects the first item in the array, and .email selects its email property.

Related Tools

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  • JSON to CSV

    Turn JSON arrays into CSV for Excel or Google Sheets, with nested object flattening and custom delimiters.

  • JSON to YAML

    Convert JSON to clean, readable YAML for Kubernetes, Docker Compose, CI pipelines, and config files.