Compare essays, articles, emails, contracts — any plain text
How to Use This Tool
Compare AI-Generated Code
Paste your original code in Version A, then paste the AI output in Version B. See exactly which lines were dropped, changed, or added — nothing gets lost silently.
Compare Document Versions
Paste two drafts of an essay, contract, or report. Every changed sentence, added paragraph, or deleted word is highlighted instantly.
Spot Missing Functions
Find functions, imports, or logic the AI accidentally omitted. Character-level highlighting catches even single-character differences inside a line.
Any Language or Format
Works with JavaScript, Python, PHP, HTML, CSS, SQL, Java, TypeScript, JSON, XML, Markdown — any plain text format. No file upload, no setup needed.
Frequently Asked Questions
Is there a character limit?▼
Each text box accepts up to 200,000 characters — about 4,000–5,000 lines of typical code — which covers virtually all real files. The counter turns orange as you approach the limit.
Does this work offline?▼
Yes. After the page loads, this tool works completely offline. Your text never leaves your browser — all processing is done in JavaScript on your device.
What languages does syntax highlighting support?▼
The highlighter recognizes keywords from JavaScript, TypeScript, Python, PHP, Java, Rust, Go, C, C++, SQL, and most scripting languages. It uses a universal token-based approach.
How is the similarity percentage calculated?▼
The similarity score is the percentage of identical lines compared to the total line count. 100% means both texts are exactly the same; 0% means no lines are shared.
Can I compare JSON or XML?▼
Yes — paste JSON or XML as plain text. The diff will highlight added, removed, and changed key-value pairs line by line with no special setup required.
100% Private. All comparison happens in your browser. Your code and text are never sent to any server. Works offline after page load.