Lychee is a link checker written in Rust that finds broken URLs and email addresses in Markdown, HTML, reStructuredText, websites, and other file formats.
The tool solves the problem of identifying dead links and invalid email addresses across documentation and web content. It uses an async, stream-based architecture to check links efficiently, processing multiple targets concurrently. The checker works across diverse input formats and can validate both hyperlinks and email addresses, making it suitable for comprehensive link validation workflows.
Lychee suits projects that need automated link verification as part of their documentation or build pipeline. It is available in three forms: a command-line utility for direct use, a library for integration into other Rust applications, and a GitHub Action for CI/CD workflows. The tool supports multiple installation methods including package managers for Linux and macOS, Docker images, Nix, and pre-built binaries for major operating systems. Optional feature flags allow enabling email address checking and validation of example domains for testing purposes.
The project maintains active development with regular updates and contributions. The codebase is built with Rust and Cargo, with Nix flake support for development environments. Documentation is comprehensive, covering command-line usage, library integration, and pre-commit hook setup. The project provides multiple distribution channels and maintains Docker images including nightly builds from the development branch.
