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JSON Diff

The most advanced visual JSON comparison platform. Instantly understand what changed, where it changed, why it changed, and how much changed. Features side-by-side and inline comparison modes, a collapsible tree view, human-readable change explanations, a change statistics dashboard, ignore options, and exportable diff reports — all running entirely in your browser with zero server uploads.

JSON A
Ln 1Col 00 charsUTF-8JSON
JSON B
Ln 1Col 00 charsUTF-8JSON

Ready to Compare JSON

Paste JSON in both panels above or load examples to see the diff engine in action.

Side by Side
Tree View
Smart Explanations

Examples

Click an example to load both JSON panels with sample data.

API Response Change

{
  "status": "ok",
  "code": 200,
  "data": {
    "id": 1,
    "name": "Widget ...

Configuration File

{
  "server": {
    "host": "localhost",
    "port": 3000,
    "ssl": false
  },...

Package.json Update

{
  "name": "forgeplug",
  "version": "2.0.0",
  "dependencies": {
    "react": ...

User Profile Edit

{
  "id": "usr_12345",
  "profile": {
    "name": "Alice Johnson",
    "email": ...

Settings Migration

{
  "display": {
    "brightness": 70,
    "fontSize": 14,
    "reducedMotion": ...

Nested Arrays

{
  "project": "ForgePlug",
  "sprints": [
    {
      "id": 1,
      "name": "S...

Frequently Asked Questions

Is my JSON data sent to a server?
No. All comparison processing happens entirely in your browser. Your JSON data never leaves your device. This is a core privacy feature of ForgePlug — everything is client-side.
How does the diff algorithm work?
The diff algorithm performs a deep structural comparison of both JSON values. It recursively traverses objects and arrays, comparing keys and values at every level. It detects added keys, removed keys, modified values, type changes, and array element changes. The result is a tree of changes that powers all visualization modes.
What is the difference between Side-by-Side and Inline view?
Side-by-side view shows both JSONs next to each other with synchronized scrolling. Lines are color-coded: green for additions, red for deletions, yellow for modifications. This is similar to GitHub's diff view. Inline view merges both versions into a single editor showing additions (green), deletions (red strikethrough), and modifications side by side.
What does the Tree View show?
The Tree View displays the structure of differences as a collapsible tree. Each node shows whether a key was added, removed, or modified. You can expand/collapse nodes, filter by change type, and click to jump to specific differences. This is the best view for understanding the hierarchical nature of changes.
Can I export the diff results?
Yes. You can download the diff report as a JSON file, a Markdown summary, a plain text report, or a CSV file. You can also copy the diff summary to your clipboard with one click. All export options include the change statistics and human-readable explanations.
What are Ignore Options?
Ignore options let you exclude certain types of differences from the comparison. You can ignore whitespace, formatting differences, key order, array order, case sensitivity, null values, and empty strings. This is useful when comparing JSON from different sources that may have formatting or structural differences that aren't semantically important.
What does 'Smart Explanation' mean?
Smart Explanations translate raw diff results into human-readable sentences. Instead of just showing 'age changed', we display 'The value of "age" changed from 24 to 25.' This makes it immediately clear what changed without manually inspecting the values.
Can I compare large JSON files?
Yes. The diff engine is optimized for performance and can handle large JSON structures. For very large files (1000+ keys), we recommend using the Tree View for easier navigation. Performance metrics are displayed in the sidebar showing processing time.
What file formats can I upload?
You can upload .json files or any text file containing valid JSON. Simply click the Upload button on either editor or drag and drop a file onto the editor area. Both files are processed entirely in your browser.

Keyboard Shortcuts

CompareCtrl+Enter
Swap A/BCtrl+Shift+S
View modesCtrl+1 / 2 / 3
Ignore optionsCtrl+I
Toggle sidebarCtrl+B
Clear allCtrl+L
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Frequently Asked Questions

Everything you need to know about comparing JSON files

Is my JSON data sent to a server?
No. All comparison processing happens entirely in your browser. Your JSON data never leaves your device. This is a core privacy feature of ForgePlug — everything is client-side.
How does the diff algorithm work?
The diff algorithm performs a deep structural comparison of both JSON values. It recursively traverses objects and arrays, comparing keys and values at every level. It detects added keys, removed keys, modified values, type changes, and array element changes. The result is a tree of changes that powers all visualization modes.
What is the difference between Side-by-Side and Inline view?
Side-by-side view shows both JSONs next to each other with synchronized scrolling. Lines are color-coded: green for additions, red for deletions, yellow for modifications. This is similar to GitHub's diff view. Inline view merges both versions into a single editor showing additions (green), deletions (red strikethrough), and modifications side by side.
What does the Tree View show?
The Tree View displays the structure of differences as a collapsible tree. Each node shows whether a key was added, removed, or modified. You can expand/collapse nodes, filter by change type, and click to jump to specific differences. This is the best view for understanding the hierarchical nature of changes.
Can I export the diff results?
Yes. You can download the diff report as a JSON file, a Markdown summary, a plain text report, or a CSV file. You can also copy the diff summary to your clipboard with one click. All export options include the change statistics and human-readable explanations.
What are Ignore Options?
Ignore options let you exclude certain types of differences from the comparison. You can ignore whitespace, formatting differences, key order, array order, case sensitivity, null values, and empty strings. This is useful when comparing JSON from different sources that may have formatting or structural differences that aren't semantically important.
What does 'Smart Explanation' mean?
Smart Explanations translate raw diff results into human-readable sentences. Instead of just showing 'age changed', we display 'The value of "age" changed from 24 to 25.' This makes it immediately clear what changed without manually inspecting the values.
Can I compare large JSON files?
Yes. The diff engine is optimized for performance and can handle large JSON structures. For very large files (1000+ keys), we recommend using the Tree View for easier navigation. Performance metrics are displayed in the sidebar showing processing time.
What file formats can I upload?
You can upload .json files or any text file containing valid JSON. Simply click the Upload button on either editor or drag and drop a file onto the editor area. Both files are processed entirely in your browser.

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