Lychee

Lychee

Fast link checker written in Rust. Finds broken URLs and mail addresses in Markdown, HTML, and other text formats.

Basic Usage

Check an entire project:

lychee .                          # Recursively check all supported files
                                  # Exit 0 = all OK, non-zero = failures found

Check a single file or URL:

lychee README.md                  # Single file
lychee 'docs/**/*.md'             # Glob (quote to prevent shell expansion)
lychee https://example.com        # Website URL

CI-Friendly Output

Disable the progress bar for scripts and CI:

lychee --no-progress .

Configuration Options

Include mail addresses and fragment anchors:

lychee --include-mail --include-fragments .

Exclude URLs or paths (regex patterns, repeatable):

lychee --exclude '^https://github\.com/' \
       --exclude-path 'node_modules' \
       .

Remap URL patterns:

lychee --remap 'https://old.com https://new.com' README.md

Debugging

• lychee --dump README.md — list extracted links without checking them
• lychee -vvv — verbose retry details
• --suggest — propose replacements via web archive

Rules

• Set GITHUB_TOKEN env var to avoid GitHub rate limits
• Use --exclude-all-private to skip private IPs and loopback
• Create lychee.toml for persistent project settings
• Use --cache . for faster repeated checks
• Use -f json or -f markdown for structured output