JSON Compare

Paste two JSON documents and see the differences — everything runs in your browser.

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Related tools JSON Formatter JSON Viewer XML Compare

Why Use Our JSON Compare?

  • Line and character-level highlights
  • Added, removed and unchanged counts
  • Synchronised scrolling between panes
  • Works completely in your browser
  • Handles config, payload and API response JSON

Features & Supported Capabilities

  • Auto-formats pasted JSON before diffing
  • Myers diff algorithm for accurate change detection
  • Handles files up to 10 MB per side
  • Optional line wrapping for long lines
  • Copy or download either side independently

About this JSON compare and diff checker

Two JSON documents can be equivalent yet look different because of spacing or layout. This free online JSON compare tool auto-formats both sides and highlights the differences line by line, making it easy to see what really changed between two API responses, configs or fixtures.

Comparison runs in your browser and nothing is uploaded. For plain text use text compare. To tidy or validate one document use the JSON formatter, or explore it in the JSON viewer.

Frequently Asked Questions

Everything you might want to know about the online JSON Compare tool.

It compares two JSON documents side by side and highlights the keys and values that were added, removed, or changed between them — useful for reviewing config changes or two versions of an API response.
Yes. Pasted JSON is auto-indented first, so two documents that differ only in whitespace or minification won't drown the real differences in formatting noise.
Line-level, with character-level highlights inside changed lines — so you can see exactly which value changed within a line, not just that it did.
No. The comparison runs entirely in your browser. Neither side's JSON is ever uploaded, stored, or logged.
You can paste text or upload a file up to 10 MB on each side.
Lines only in the left document are marked as removed, lines only in the right document are marked as added, and unchanged lines are shown without a highlight.
Yes, each side's JSON can be copied or downloaded independently, the same as the other editors on this site.
Yes. Identical head and tail regions are trimmed before diffing, so documents that share long identical sections compare quickly even at tens of thousands of lines.
The JSON Formatter tidies one document. JSON Compare takes two documents and shows exactly what's different between them.