JSON Diff

Compare two JSON objects side-by-side and see exactly what changed. Highlighted additions, removals, and modifications. 100% client-side.

Original JSON

Modified

About JSON Diff & Comparator

JSON Diff & Comparator is a free online tool that helps developers, QA engineers, and data analysts compare two JSON objects side-by-side and instantly identify differences. All processing happens entirely in your browser — no data is ever sent to a server, ensuring complete privacy and security. The tool highlights additions, removals, and modifications with color-coded visual indicators, making it easy to spot changes at a glance.

Features

Side-by-Side Comparison — Paste two JSON objects and see differences instantly
Color-Coded Highlights — Added (green), Removed (red), and Modified (yellow) fields
Deep Object Comparison — Recursively compares nested objects and arrays
Type-Aware Detection — Identifies when values change type (e.g., string to number)
Clear & Reset — One-click buttons to clear inputs or start a fresh comparison
Copy Results — Copy the diff output to clipboard for sharing or documentation
Error Detection — Validates JSON syntax and reports parse errors with clear messages
Visual Indicators — Clear labels and icons for Added, Removed, Modified, and Unchanged fields
Large JSON Support — Handles complex, deeply nested JSON objects efficiently
100% Client-Side — No server uploads, your data stays private and secure

How to Use

Paste your original JSON into the left textarea (Original JSON)
Paste your modified JSON into the right textarea (Modified JSON)
Click the "Compare JSON" button to run the comparison
Review the diff results showing Added, Removed, and Modified fields
Use "Copy Result" to copy the diff output to your clipboard
Click "Clear Both" to reset and start a new comparison

Common Use Cases

Verify API response changes between development and production environments
Review configuration file changes during code reviews and deployments
Compare database export snapshots to track schema or data changes
Debug JSON parsing issues by comparing expected vs actual outputs
Track changes in translation files, settings, or feature flag configurations
Validate data migration results by comparing source and target JSON datasets

Frequently Asked Questions

Is my JSON data safe when using this tool?

Yes, absolutely. All comparison processing happens entirely in your browser using JavaScript. Your JSON data is never sent to any server, ensuring complete privacy and security.

What types of differences does the tool detect?

The tool detects three main types of differences: Added (fields present in the modified JSON but not in the original), Removed (fields present in the original but not in the modified), and Modified (fields present in both but with different values).

Does the tool handle nested objects and arrays?

Yes, the tool recursively compares nested objects and arrays. It traverses the entire JSON structure to find differences at any depth level.

Can I compare large JSON files?

Yes, the tool is designed to handle large and complex JSON objects. However, extremely large files (megabytes) may cause browser performance issues. For most practical use cases, it works instantly.

What if my JSON is invalid?

The tool validates both JSON inputs before comparison. If either input contains invalid JSON, an error message will be displayed indicating which field has the issue.

Can I copy the diff results?

Yes, click the "Copy Result" button to copy the formatted diff output to your clipboard. You can then paste it into documentation, emails, or issue trackers.

Does the tool show unchanged fields?

The primary view focuses on differences (Added, Removed, Modified). Unchanged fields are typically hidden to reduce noise, but the underlying comparison engine tracks all fields.

Can I compare JSON arrays?

Yes, the tool handles JSON arrays and objects. It compares array elements by index and reports additions, removals, and modifications within arrays.