Compare Text & Code Instantly

Diff two files, code snippets, or documents side by side — right in your browser. No uploads, no accounts, fully offline.

Add to Chrome — It's Free

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Everything you need to compare smarter

Side-by-Side & Unified Diff

View changes in split or inline mode. Color-coded additions, deletions, and modifications with line numbers.

20+ Languages with Syntax Highlighting

Compare JavaScript, Python, HTML, CSS, JSON, and more with automatic language detection and Prism-powered highlighting.

AI-Powered Change Summaries

Connect your OpenAI API key for concise explanations of what changed. Full-text or diff-only analysis modes.

Office Document Support

Compare DOCX and XLSX files converted to text right in the browser. No server uploads required.

Smart Formatting & Normalization

One-click code formatting, sort object keys, normalize whitespace, and reorder CSS properties before comparing.

100% Private & Offline

All comparisons run locally in your browser. No data leaves your machine. No tracking, no analytics, no accounts.

See It in Action

Side-by-side text comparison with color-coded additions and deletions
Paste two texts and click Compare Code diff view with syntax highlighting Compare source code of two open browser tabs

How It Works

Start comparing in under a minute.

1

Install the Extension

Add Diff Checker to Chrome in one click. Free and lightweight.

2

Paste or Upload Content

Paste two texts, upload files (code, DOCX, XLSX), or load source from open tabs.

3

See the Difference

Instantly view additions, deletions, and changes with color-coded highlighting.