A fully browser-based text and file diff tool. No server. No uploads. No accounts. Your data never leaves your machine.
https://tahametin.github.io/DiffTool/
Most online diff tools send your text to a remote server for processing. That's a problem when you're comparing source code, configuration files, contracts, API keys, internal documents, or anything else you'd rather keep private.
DiffTool was built with one goal: give you a professional-grade diff experience that works entirely on your own device. Everything runs in your browser using vanilla JavaScript — no backend, no telemetry, no data collection of any kind.
- Text & File modes — paste text directly or drag & drop any file (TXT, JS, PY, HTML, JSON, XML, CSV, MD, and more)
- Advanced Diff Engine — high-performance comparison using the Myers Diff Algorithm with prefix/suffix stripping optimizations
- Syntax Highlighting — professional code highlighting for JavaScript, Python, HTML, CSS, C-like, and more (via Prism.js)
- Interactive Minimap — high-level overview of changes with draggable viewport for quick navigation
- Action History — locally stored history of your previous comparisons to quickly jump back to work
- Word-level diff — highlights exactly which words changed within a modified line
- Side-by-side & Unified views — switch between layouts depending on your preference
- Fullscreen Mode — distraction-free comparison with zoom controls and synchronized navigation
- Bilingual Support — fully localized UI in both Turkish and English
- Statistics — added, deleted, modified, and unchanged line counts at a glance
- Export — download results as HTML or plain text, or copy to clipboard
- Keyboard shortcuts —
F7/Shift+F7for navigation,Ctrl+Enterto compare instantly
No installation. No dependencies. No build step.
- Download
index.html - Open it in your browser
- Start comparing
That's it. The file is fully self-contained — one HTML file with all CSS and JavaScript included.
- Local Processing — All diffing and rendering happen locally in your browser.
- Zero Data Leakage — Nothing is ever sent to a server.
- Action History — Stored exclusively in your browser's
localStorage. You can clear it at any time. - Security First — Inputs are rigorously escaped to prevent XSS (Cross-Site Scripting) attacks.
- Zero Tracking Cookies — No analytics, no tracking, no third-party scripts.
- Offline Ready — Works completely offline after the initial load.
/
└── index.html # The entire application — open this in your browser
└── README.md
MIT — do whatever you want with it.