🔍 JSON Compare
Compare two JSON objects side by side. Find added, removed, and changed keys instantly.
📋 When to Use the JSON Compare
The JSON Compare is ideal when you need to spot differences between two JSON objects quickly — whether you're debugging API response changes, reviewing configuration file updates between deployments, or validating that a refactored data model hasn't introduced regressions. Use it during code reviews to check JSON payload changes, when migrating data schemas between service versions, or when collaborating on shared data structures where you need to track what's been added, removed, or modified. Everything processes in your browser for maximum privacy — no data is uploaded.
⚙️ How the JSON Compare Works
The JSON Compare processes both inputs entirely in your browser using JavaScript. When you paste two JSON objects, the tool parses each one and compares their top-level keys. For each key, it determines whether the value was added (exists in right but not left), removed (exists in left but not right), or changed (same key, different value). A key whose nested value differs is flagged as changed, and both full values are shown (via JSON.stringify) so you can see the before and after — the tool does not report which nested path changed or compare arrays element-by-element. The entire diff pipeline — parse, compare, render — stays on your device; no data is ever sent to a server.
How to Use JSON Compare
- Paste JSON in both panels — put the original/old JSON on the left and the new/modified JSON on the right. The tool comes pre-filled with sample data.
- View the diff instantly — the output shows added keys (🟢 green), removed keys (🔴 red), and changed values (🟡 yellow for modified) with clear visual indicators.
- Drill into nested changes — the comparison walks top-level keys only, so a key with a changed nested value is flagged as changed and both full values are shown; it does not pinpoint which nested path differs or diff arrays element-by-element.
- Copy and iterate — use the diff to understand what changed between API response versions, config files, or data exports.
Frequently Asked Questions
How does JSON Compare handle arrays?
The tool does not compare arrays element-by-element. Arrays only participate in the comparison when they are the value of a top-level key: if that whole array differs (by its JSON.stringify string), the key is flagged as changed and both full arrays are shown side by side. It does not match items by index or by value, so for element-level or reordered-array diffs, use a dedicated JSON diff tool.
Can I compare deeply nested objects?
Not with a per-level diff. The tool only walks top-level keys, so it does not recurse into nested objects to report which inner field changed. If a top-level key holds a nested object or array whose contents differ, that key is flagged as changed and both full values are shown (via JSON.stringify) so you can compare them by eye. For a path-level breakdown of deep changes, use a dedicated recursive JSON diff tool.
What if my JSON has syntax errors?
The tool will show an error message if either input isn't valid JSON. Use the JSON Formatter first to validate and fix syntax issues, then come back to compare.
Is this suitable for comparing large configuration files?
Yes, for files up to a few megabytes. For very large JSON files (100MB+), browser memory may become a limitation. For enterprise-scale comparisons, consider command-line tools like jq with diff.