diff2html is a JavaScript library that converts git diff or unified diff output into formatted HTML with syntax highlighting and visual styling.
The tool solves the problem of presenting code diffs in a human-readable format by parsing diff text and rendering it as styled HTML. It supports both line-by-line and side-by-side comparison views, displays line numbers for both old and new versions, and applies syntax highlighting to the code. The library includes line similarity matching to help identify related changes across insertions and removals.
Developers should choose this tool when building applications that need to display diffs to users, such as code review interfaces, documentation sites, or development tools. It works well for projects that consume git or unified diff output and want to present it with GitHub-like visual styling without building a diff renderer from scratch. The tool is available as both a browser library and an NPM package for Node.js environments, making it suitable for frontend applications, backend services, or full-stack implementations.
The project maintains active development with regular updates addressing performance concerns and expanding functionality. The codebase is written in TypeScript, providing type safety for integrations. The tool includes comprehensive configuration options for customizing output behavior and appearance. Documentation covers multiple usage patterns including direct API calls and UI wrapper components, with troubleshooting guidance for handling large diffs that may cause performance issues.
