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  5. Compare
Semantic diff, not just text diff

Compare Two JSON FilesSide by Side

Intelligent JSON comparison that understands structure, not just text. See exactly what was added, removed, or changed with color-coded highlighting and JSONPath navigation.

Added
Removed
Changed
Type Changed
Moved
Start Comparing
Compare Mode - Paste JSON in both panels
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Smart Comparison Features

Our JSON comparison tool goes beyond simple text diff to understand JSON structure and provide meaningful, actionable differences.

🎯

Semantic Diff

Understands JSON structure, not just text. Object key order doesn't matter, but array order does.

🔀

Array Move Detection

Detects when array elements are reordered, showing 'moved from index X to index Y' context.

📍

JSONPath Navigation

Each difference shows its JSONPath location for easy identification in large files.

🎨

Color-Coded Highlighting

Green for added, red for removed, amber for changed, purple for type changes.

📊

Comparison Statistics

Summary of total additions, removals, changes, and type changes at a glance.

⌨️

Keyboard Navigation

Use arrow keys to quickly navigate between differences in the diff list.

Understanding Diff Types

The comparison tool categorizes every difference into one of four types, making it easy to understand exactly what changed.

Added

New keys or values present in the modified JSON but not in the original

Example:

Modified has "newField": true that original doesn't have

Removed

Keys or values present in the original JSON but missing from the modified

Example:

Original has "oldField": false that modified doesn't have

Changed

Same key exists in both but with a different value

Example:

"count": 5 in original → "count": 10 in modified

Type Changed

Same key exists in both but the value type is different

Example:

"id": "123" (string) → "id": 123 (number)

Moved

Array element exists in both but at a different position (array order matters)

Example:

"a": [1,2,3] → "a": [2,1,3] shows 1 moved from [0] to [1]

When to Use JSON Comparison

JSON comparison is essential for many development and debugging workflows.

🔧

API Response Debugging

Compare API responses before and after changes to verify data is correct

⚙️

Configuration Management

Track changes between config file versions across environments

🔄

Data Migration Verification

Ensure data was migrated correctly by comparing source and destination

📋

Code Review

Review JSON schema or fixture changes in pull requests

🐛

Bug Investigation

Compare expected vs actual output to identify where things went wrong

📦

Package.json Changes

See exactly what dependencies were added, removed, or updated

Frequently Asked Questions

Everything you need to know about comparing JSON files online.

What is semantic JSON diff?

Semantic JSON diff understands JSON structure instead of just comparing text line-by-line. This means reordered keys in objects won't show as changes, array modifications are tracked intelligently, and you see meaningful differences like 'value changed from X to Y' rather than just 'line removed, line added'.

How does the JSON comparison tool handle arrays?

Our tool understands that array order matters in JSON. When elements are reordered, it detects this and shows them as 'moved' with the exact position change (e.g., 'moved from index 0 to index 2'). When an element is deleted, only that deletion is shown - not every subsequent element as 'moved'.

Does object key order matter when comparing JSON?

No, object key order doesn't matter in JSON comparison. {"a": 1, "b": 2} is semantically equal to {"b": 2, "a": 1}, so our tool treats them as identical. However, array element order DOES matter - [1, 2] is different from [2, 1], and we show exactly which elements moved.

Is my JSON data safe when comparing files?

Yes, completely. All comparison processing happens in your browser using JavaScript. Neither of your JSON files is ever uploaded to any server. This makes it safe for comparing configuration files containing API keys, secrets, or sensitive data.

What types of differences can the tool detect?

The tool detects five types of differences: Added (new keys/values), Removed (deleted keys/values), Changed (same key, different value), Type Changed (e.g., string to number), and Moved (array elements that changed position with exact from/to indices).

Can I navigate between differences quickly?

Yes! The diff list shows all differences and you can click any item to jump directly to it. You can also use keyboard shortcuts (arrow up/down) to navigate between differences. The current difference is highlighted in both panels.

How do I compare two JSON files online?

Simply paste your original JSON in the left panel and your modified JSON in the right panel, then click 'Compare'. The tool will analyze both files and show you all differences with color-coded highlighting: green for added, red for removed, amber for changed.

Can I compare large JSON files?

Yes! Since all processing happens in your browser, there's no upload size limit. The tool uses efficient algorithms (LCS for line alignment, similarity matching for arrays) to handle large files quickly. Performance depends on your device's memory and processing power.

How JSON Comparison Works

Our intelligent algorithm uses multiple techniques to give you accurate, meaningful diffs.

1

Parse & Validate

Both JSON files are parsed and validated. Invalid JSON is highlighted with error messages so you can fix it before comparing.

2

Deep Comparison

The tool recursively compares objects and arrays. Object keys are compared regardless of order. Array elements are matched using the LCS algorithm.

3

Diff Classification

Each difference is classified as Added, Removed, Changed, Type Changed, or Moved. Results are displayed with JSONPath for easy navigation.

Algorithm Details

LCS (Longest Common Subsequence)

For arrays, we use LCS to find elements that maintained their relative order. This prevents showing every element as "moved" when you just delete one item.

Similarity Matching

When objects in arrays are modified, we use similarity scores to match them correctly. This lets us show what changed inside the object rather than "removed + added".

Compare Confidential Data Safely

Both JSON files are compared entirely in your browser. Neither file is ever uploaded to any server. This makes it safe for comparing config files with secrets, API responses with user data, or any other sensitive information.

Both files processed locally
No server-side comparison
Safe for secrets and credentials
Works offline after page load

Related JSON Tools

✨

JSON Formatter

Format and beautify JSON with customizable indentation. Minify for production use.

🔧

JSON Auto-Fix

Automatically repair invalid JSON. Fix trailing commas, quotes, and more.

📖

Full Documentation

Complete guide to all JSON tools including transform, encode/decode, and more.