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JSON Diff — Compare JSON Online & See Every Difference

Compare two JSON objects side-by-side and see every added, removed, and changed field — including nested differences. Free, no sign-up, all client-side.

No uploads. Everything runs locally in your browser.

Need to compare JSON objects and spot every difference? Our online JSON diff tool shows added, removed, and changed fields with full dot-notation paths — including nested objects and arrays. Use it to diff JSON between API versions, review JSON config changes before deploying, or debug data discrepancies — all client-side, no sign-up.

Status

Sample loaded. Click Compare to see differences!

Left JSON (original)
Right JSON (modified)
Differences
+2 added~1 changed
changed
age← 30  → 31
added
roles.1→ "admin"
added
city→ "London"

Quick examples

What is a JSON Diff Tool?

A JSON diff tool compares two JSON objects — an original and a modified version — and identifies every difference between them. It detects added fields (present in right, missing in left), removed fields, and changed values. Unlike text-based diff tools, a JSON compare engine understands nested structures and reports changes with precise dot-notation paths like user.address.city. All processing runs in your browser.

How JSON Diffing Works

  1. Both JSON inputs are parsed into JavaScript objects.
  2. The diff engine walks every key recursively through nested objects and arrays.
  3. Each field is compared: missing = added/removed, different value = changed.
  4. Results are displayed with color-coded categories and full field paths.

How to use JSON Diff

  1. Paste your original JSON on the left and the modified JSON on the right.
  2. Click Compare to run the diff and see all added, removed, and changed fields.
  3. Swap sides to flip, load examples to test, or clear to start fresh.

Key features of JSON Diff

  • Deep recursive comparison that traverses nested objects and arrays automatically
  • Color-coded diff results: green for added, red for removed, amber for changed fields
  • Dot-notation paths showing exactly where each change occurred in the JSON structure
  • Diff summary stats with filter toggles — hide/show added, removed, or changed diffs
  • Format Both button — auto-pretty-prints minified JSON on both sides with one click
  • Copy Results to clipboard for pasting into PRs, tickets, or documentation
  • All comparison happens in your browser — zero uploads, instant results

JSON Diff — key benefits

  • Completely free with no signup or registration required.
  • Runs entirely in your browser — your data is never uploaded.
  • Works on desktop, tablet, and mobile devices.
  • Instant results with no waiting or processing queues.
  • Part of the ToolCircuit suite of free online developer tools tools.

When to Use This JSON Diff Tool

🔄 API Version Migration

Compare JSON responses from v1 and v2 of an API. Spot new fields, deprecated fields, and changed data types before updating your client code.

⚙️ Config File Review

Diff production vs staging JSON configs before deploying. Catch unintended changes in environment variables, feature flags, or database settings.

🐛 Debugging Data Issues

Compare expected vs actual JSON output from your backend. Find exactly which field is wrong and at what nesting level — no more manual scanning.

📋 Code Review & PR Checks

Paste before/after API response examples in pull requests. The JSON diff visual makes it obvious what changed without reading raw JSON side by side.

Pro Tips for JSON Comparison

  • Sort keys before diffing — use the JSON Formatter with key sorting enabled on both inputs first. Identical objects with different key order will show false "changed" diffs if keys aren't sorted.
  • Swap sides to verify — sometimes the diff is clearer when you flip left and right. Use the Swap button to instantly reverse the comparison direction.
  • Minify JSON before pasting — removes extra whitespace that can cause parsing issues. The diff engine works on the parsed object, not the raw text, so minified input is fine.
  • Use with version control — pair this online JSON diff tool with Git to review JSON config changes between commits before merging pull requests.

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FAQ

Is this JSON diff tool free?

Yes — completely free, no sign-up required. All comparison happens in your browser for privacy.

Does it handle nested JSON objects?

Yes — the diff engine recursively walks nested objects and arrays, reporting changes at every level with full dot-notation paths like user.address.city.

What types of changes does it detect?

Three types: added (new field in right), removed (field missing from right), and changed (same field, different value). Arrays are compared element-by-element.

Does it upload my JSON data?

No. Both JSON inputs stay on your device. All parsing and comparison is done client-side with zero network requests.

Can I compare large JSON files?

Yes, but performance depends on your device. Files up to a few hundred KB with moderate nesting should compare instantly. Extremely deep nesting (50+ levels) may be slower.

What's the difference between JSON Diff and JSON Formatter?

JSON Diff compares two JSON objects to find differences — use it for reviewing API changes or config updates. JSON Formatter beautifies or minifies a single JSON input for readability.

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