How does the comparison work?

Both documents are parsed and compared structurally, not as text. That means formatting differences, key order and whitespace are ignored — only actual data differences (additions, removals and value changes) are reported.

How are arrays compared?

Arrays are compared element by element, by index. If B has extra elements they are reported as additions; missing ones as removals. Elements are never 'matched' across positions, so reordering an array shows as a series of changes.

Is my data sent to a server?

No. The comparison runs entirely in your browser. Neither document is uploaded, stored or logged anywhere.

What do the +, − and ± symbols mean?

+ marks a value that exists only in B (added). − marks a value that exists only in A (removed). ± marks a value present in both but different, shown with old and new values side by side.

Can I compare JSON files from disk?

Yes. Use the upload button above either editor to load a .json file, then press Compare. Files are read locally in your browser.

JSON Diff

Compare two JSON documents and highlight additions, removals and changed values with paths.

Runs in your browser — your data never leaves your deviceFree, no sign-up

JSON A (original)

Upload file

JSON B (changed)

Upload file

Differences

Differences between A and B will appear here.

How it works

Both documents are parsed into memory and compared recursively. Every difference is reported with its full path — for example labels.env or ports[1] — plus the value(s) involved, so you can locate the change immediately even in large files.

Because the comparison is semantic, two documents that differ only in formatting or key order are correctly reported as identical.

Features

Structural comparison — ignores formatting and key order
Additions, removals and changes reported with full paths
Old → new values shown side by side for changes
Summary counts and a copyable plain-text result
Per-side formatting and file upload
100% client-side — nothing is uploaded

How to use

Paste the original JSON into A and the modified JSON into B (or upload both files).
Optionally press Format on either side to tidy it first.
Press Compare.
Read the differences, or copy the result as text.

Example

Comparing {"port":8080,"debug":true} (A) with {"port":9090} (B) reports: debug removed, and port changed from 8080 to 9090.

Frequently asked questions

How does the comparison work?: Both documents are parsed and compared structurally, not as text. That means formatting differences, key order and whitespace are ignored — only actual data differences (additions, removals and value changes) are reported.
How are arrays compared?: Arrays are compared element by element, by index. If B has extra elements they are reported as additions; missing ones as removals. Elements are never 'matched' across positions, so reordering an array shows as a series of changes.
Is my data sent to a server?: No. The comparison runs entirely in your browser. Neither document is uploaded, stored or logged anywhere.
What do the +, − and ± symbols mean?: + marks a value that exists only in B (added). − marks a value that exists only in A (removed). ± marks a value present in both but different, shown with old and new values side by side.
Can I compare JSON files from disk?: Yes. Use the upload button above either editor to load a .json file, then press Compare. Files are read locally in your browser.