[](https://lycheeverse.github.io) [](https://github.com/marketplace/actions/lychee-broken-link-checker)  [](https://docs.rs/lychee-lib) [](https://github.com/lycheeverse/lychee/actions/workflows/links.yml) [](https://hub.docker.com/r/lycheeverse/lychee) ⚡ A fast, async, stream-based link checker written in Rust.\ Finds broken hyperlinks and mail addresses inside Markdown, HTML, reStructuredText, or any other text file or website! Available as a command-line utility, a library and a [GitHub Action](https://github.com/lycheeverse/lychee-action).  ## Table of Contents - [Installation](#installation) - [Features](#features) - [Commandline usage](#commandline-usage) - [Library usage](#library-usage) - [GitHub Action Usage](#github-action-usage) - [Contributing to lychee](#contributing-to-lychee) - [Debugging and improving async code](#debugging-and-improving-async-code) - [Troubleshooting and Workarounds](#troubleshooting-and-workarounds) - [Users](#users) - [Credits](#credits) - [License](#license) ## Installation ### Arch Linux ```sh pacman -S lychee ``` ### macOS ```sh brew install lychee ``` ### Docker ```sh docker pull lycheeverse/lychee ``` ### NixOS ```sh nix-env -iA nixos.lychee ``` ### FreeBSD ```sh pkg install lychee ``` ### Scoop ```sh scoop install lychee ``` ### Termux ```sh pkg install lychee ``` ### Pre-built binaries We provide binaries for Linux, macOS, and Windows for every release. \ You can download them from the [releases page](https://github.com/lycheeverse/lychee/releases). ### Cargo #### Build dependencies On APT/dpkg-based Linux distros (e.g. Debian, Ubuntu, Linux Mint and Kali Linux) the following commands will install all required build dependencies, including the Rust toolchain and `cargo`: ```sh curl -sSf 'https://sh.rustup.rs' | sh apt install gcc pkg-config libc6-dev libssl-dev ``` #### Compile and install lychee ```sh cargo install lychee ``` #### Feature flags Lychee supports several feature flags: - `native-tls` enables the platform-native TLS crate [native-tls](https://crates.io/crates/native-tls). - `vendored-openssl` compiles and statically links a copy of OpenSSL. See the corresponding feature of the [openssl](https://crates.io/crates/openssl) crate. - `rustls-tls` enables the alternative TLS crate [rustls](https://crates.io/crates/rustls). - `email-check` enables checking email addresses using the [check-if-email-exists](https://crates.io/crates/check-if-email-exists) crate. This feature requires the `native-tls` feature. - `check_example_domains` allows checking example domains such as `example.com`. This feature is useful for testing. By default, `native-tls` and `email-check` are enabled. ## Features This comparison is made on a best-effort basis. Please create a PR to fix outdated information. | | lychee | [awesome_bot] | [muffet] | [broken-link-checker] | [linkinator] | [linkchecker] | [markdown-link-check] | [fink] | | -------------------- | ------- | ------------- | -------- | --------------------- | ------------ | -------------------- | --------------------- | ------ | | Language | Rust | Ruby | Go | JS | TypeScript | Python | JS | PHP | | Async/Parallel | ![yes] | ![yes] | ![yes] | ![yes] | ![yes] | ![yes] | ![yes] | ![yes] | | JSON output | ![yes] | ![no] | ![yes] | ![yes] | ![yes] | ![maybe]¹ | ![yes] | ![yes] | | Static binary | ![yes] | ![no] | ![yes] | ![no] | ![no] | ️![no] | ![no] | ![no] | | Markdown files | ![yes] | ![yes] | ![no] | ![no] | ![no] | ![yes] | ![yes] | ![no] | | HTML files | ![yes] | ![no] | ![no] | ![yes] | ![yes] | ![no] | ![yes] | ![no] | | Text files | ![yes] | ![no] | ![no] | ![no] | ![no] | ![no] | ![no] | ![no] | | Website support | ![yes] | ![no] | ![yes] | ![yes] | ![yes] | ![yes] | ![no] | ![yes] | | Chunked encodings | ![yes] | ![maybe] | ![maybe] | ![maybe] | ![maybe] | ![no] | ![yes] | ![yes] | | GZIP compression | ![yes] | ![maybe] | ![maybe] | ![yes] | ![maybe] | ![yes] | ![maybe] | ![no] | | Basic Auth | ![yes] | ![no] | ![no] | ![yes] | ![no] | ![yes] | ![no] | ![no] | | Custom user agent | ![yes] | ![no] | ![no] | ![yes] | ![no] | ![yes] | ![no] | ![no] | | Relative URLs | ![yes] | ![yes] | ![no] | ![yes] | ![yes] | ![yes] | ![yes] | ![yes] | | Anchors/Fragments | ![yes] | ![no] | ![no] | ![no] | ![no] | ![yes] | ![yes] | ![no] | | Skip relative URLs | ![yes] | ![no] | ![no] | ![maybe] | ![no] | ![no] | ![no] | ![no] | | Include patterns | ![yes]️ | ![yes] | ![no] | ![yes] | ![no] | ![no] | ![no] | ![no] | | Exclude patterns | ![yes] | ![no] | ![yes] | ![yes] | ![yes] | ![yes] | ![yes] | ![yes] | | Handle redirects | ![yes] | ![yes] | ![yes] | ![yes] | ![yes] | ![yes] | ![yes] | ![yes] | | Ignore insecure SSL | ![yes] | ![yes] | ![yes] | ![no] | ![no] | ![yes] | ![no] | ![yes] | | File globbing | ![yes] | ![yes] | ![no] | ![no] | ![yes] | ![no] | ![yes] | ![no] | | Limit scheme | ![yes] | ![no] | ![no] | ![yes] | ![no] | ![yes] | ![no] | ![no] | | [Custom headers] | ![yes] | ![no] | ![yes] | ![no] | ![no] | ![no] | ![yes] | ![yes] | | Summary | ![yes] | ![yes] | ![yes] | ![maybe] | ![yes] | ![yes] | ![no] | ![yes] | | `HEAD` requests | ![yes] | ![yes] | ![no] | ![yes] | ![yes] | ![yes] | ![no] | ![no] | | Colored output | ![yes] | ![maybe] | ![yes] | ![maybe] | ![yes] | ![yes] | ![no] | ![yes] | | [Filter status code] | ![yes] | ![yes] | ![no] | ![no] | ![no] | ![no] | ![yes] | ![no] | | Custom timeout | ![yes] | ![yes] | ![yes] | ![no] | ![yes] | ![yes] | ![no] | ![yes] | | E-mail links | ![yes] | ![no] | ![no] | ![no] | ![no] | ![yes] | ![no] | ![no] | | Progress bar | ![yes] | ![yes] | ![no] | ![no] | ![no] | ![yes] | ![yes] | ![yes] | | Retry and backoff | ![yes] | ![no] | ![no] | ![no] | ![yes] | ![no] | ![yes] | ![no] | | Skip private domains | ![yes] | ![no] | ![no] | ![no] | ![no] | ![no] | ![no] | ![no] | | [Use as library] | ![yes] | ![yes] | ![no] | ![yes] | ![yes] | ![no] | ![yes] | ![no] | | Quiet mode | ![yes] | ![no] | ![no] | ![no] | ![yes] | ![yes] | ![yes] | ![yes] | | [Config file] | ![yes] | ![no] | ![no] | ![no] | ![yes] | ![yes] | ![yes] | ![no] | | Cookies | ![yes] | ![no] | ![yes] | ![no] | ![no] | ![yes] | ![no] | ![yes] | | Recursion | ![no] | ![no] | ![yes] | ![yes] | ![yes] | ![yes] | ![yes] | ![no] | | Amazing lychee logo | ![yes] | ![no] | ![no] | ![no] | ![no] | ![no] | ![no] | ![no] | [awesome_bot]: https://github.com/dkhamsing/awesome_bot [muffet]: https://github.com/raviqqe/muffet [broken-link-checker]: https://github.com/stevenvachon/broken-link-checker [linkinator]: https://github.com/JustinBeckwith/linkinator [linkchecker]: https://github.com/linkchecker/linkchecker [markdown-link-check]: https://github.com/tcort/markdown-link-check [fink]: https://github.com/dantleech/fink [yes]: ./assets/yes.svg [no]: ./assets/no.svg [maybe]: ./assets/maybe.svg [custom headers]: https://github.com/rust-lang/crates.io/issues/788 [filter status code]: https://github.com/tcort/markdown-link-check/issues/94 [skip private domains]: https://github.com/appscodelabs/liche/blob/a5102b0bf90203b467a4f3b4597d22cd83d94f99/url_checker.go [use as library]: https://github.com/raviqqe/liche/issues/13 [config file]: https://github.com/lycheeverse/lychee/blob/master/lychee.example.toml ¹ Other machine-readable formats like CSV are supported. ## Commandline usage Recursively check all links in supported files inside the current directory ```sh lychee . ``` You can also specify various types of inputs: ```sh # check links in specific local file(s): lychee README.md lychee test.html info.txt # check links on a website: lychee https://endler.dev # check links in directory but block network requests lychee --offline path/to/directory # check links in a remote file: lychee https://raw.githubusercontent.com/lycheeverse/lychee/master/README.md # check links in local files via shell glob: lychee ~/projects/*/README.md # check links in local files (lychee supports advanced globbing and ~ expansion): lychee "~/projects/big_project/**/README.*" # ignore case when globbing and check result for each link: lychee --glob-ignore-case --verbose "~/projects/**/[r]eadme.*" # check links from epub file (requires atool: https://www.nongnu.org/atool) acat -F zip {file.epub} "*.xhtml" "*.html" | lychee - ``` lychee parses other file formats as plaintext and extracts links using [linkify](https://github.com/robinst/linkify). This generally works well if there are no format or encoding specifics, but in case you need dedicated support for a new file format, please consider creating an issue. ### Docker Usage Here's how to mount a local directory into the container and check some input with lychee. - The `--init` parameter is passed so that lychee can be stopped from the terminal. - We also pass `-it` to start an interactive terminal, which is required to show the progress bar. - The `--rm` removes not used anymore container from the host after the run (self-cleanup). - The `-w /input` points to `/input` as the default workspace - The `-v $(pwd):/input` does local volume mounting to the container for lychee access. > By default a Debian-based Docker image is used. If you want to run an Alpine-based image, use the `latest-alpine` tag. > For example, `lycheeverse/lychee:latest-alpine` #### Linux/macOS shell command ```sh docker run --init -it --rm -w /input -v $(pwd):/input lycheeverse/lychee README.md ``` #### Windows PowerShell command ```powershell docker run --init -it --rm -w /input -v ${PWD}:/input lycheeverse/lychee README.md ``` ### GitHub Token To avoid getting rate-limited while checking GitHub links, you can optionally set an environment variable with your GitHub token like so `GITHUB_TOKEN=xxxx`, or use the `--github-token` CLI option. It can also be set in the config file. [Here is an example config file][config file]. The token can be generated on your [GitHub account settings page](https://github.com/settings/tokens). A personal access token with no extra permissions is enough to be able to check public repo links. For more scalable organization-wide scenarios you can consider a [GitHub App][github-app-overview]. It has a higher rate limit than personal access tokens but requires additional configuration steps on your GitHub workflow. Please follow the [GitHub App Setup][github-app-setup] example. [github-app-overview]: https://docs.github.com/en/apps/overview [github-app-setup]: https://github.com/github/combine-prs/blob/main/docs/github-app-setup.md#github-app-setup ### Commandline Parameters There is an extensive list of command line parameters to customize the behavior. See below for a full list. ```text A fast, async link checker Finds broken URLs and mail addresses inside Markdown, HTML, `reStructuredText`, websites and more! Usage: lychee [OPTIONS] ... Arguments: ... The inputs (where to get links to check from). These can be: files (e.g. `README.md`), file globs (e.g. `"~/git/*/README.md"`), remote URLs (e.g. `https://example.com/README.md`) or standard input (`-`). NOTE: Use `--` to separate inputs from options that allow multiple arguments Options: -c, --config Configuration file to use [default: lychee.toml] -v, --verbose... Set verbosity level; more output per occurrence (e.g. `-v` or `-vv`) -q, --quiet... Less output per occurrence (e.g. `-q` or `-qq`) -n, --no-progress Do not show progress bar. This is recommended for non-interactive shells (e.g. for continuous integration) --cache Use request cache stored on disk at `.lycheecache` --max-cache-age Discard all cached requests older than this duration [default: 1d] --dump Don't perform any link checking. Instead, dump all the links extracted from inputs that would be checked --dump-inputs Don't perform any link extraction and checking. Instead, dump all input sources from which links would be collected --archive Specify the use of a specific web archive. Can be used in combination with `--suggest` [possible values: wayback] --suggest Suggest link replacements for broken links, using a web archive. The web archive can be specified with `--archive` -m, --max-redirects Maximum number of allowed redirects [default: 5] --max-retries Maximum number of retries per request [default: 3] --max-concurrency Maximum number of concurrent network requests [default: 128] -T, --threads Number of threads to utilize. Defaults to number of cores available to the system -u, --user-agent User agent [default: lychee/0.14.0] -i, --insecure Proceed for server connections considered insecure (invalid TLS) -s, --scheme Only test links with the given schemes (e.g. https). Omit to check links with any other scheme. At the moment, we support http, https, file, and mailto --offline Only check local files and block network requests --include URLs to check (supports regex). Has preference over all excludes --exclude Exclude URLs and mail addresses from checking (supports regex) --exclude-file Deprecated; use `--exclude-path` instead --exclude-path Exclude file path from getting checked -E, --exclude-all-private Exclude all private IPs from checking. Equivalent to `--exclude-private --exclude-link-local --exclude-loopback` --exclude-private Exclude private IP address ranges from checking --exclude-link-local Exclude link-local IP address range from checking --exclude-loopback Exclude loopback IP address range and localhost from checking --exclude-mail Exclude all mail addresses from checking (deprecated; excluded by default) --include-mail Also check email addresses --remap Remap URI matching pattern to different URI --header

Custom request header -a, --accept A List of accepted status codes for valid links The following accept range syntax is supported: [start]..[=]end|code. Some valid examples are: - 200..=204 - 200..204 - ..=204 - ..204 - 200 Use "lychee --accept '200..=204, 429, 500' ..." to provide a comma- separated list of accepted status codes. This example will accept 200, 201, 202, 203, 204, 429, and 500 as valid status codes. [default: 100..=103,200..=299,403..=403] --include-fragments Enable the checking of fragments in links -t, --timeout Website timeout in seconds from connect to response finished [default: 20] -r, --retry-wait-time Minimum wait time in seconds between retries of failed requests [default: 1] -X, --method Request method [default: get] -b, --base Base URL or website root directory to check relative URLs e.g. https://example.com or `/path/to/public` --basic-auth Basic authentication support. E.g. `http://example.com username:password` --github-token GitHub API token to use when checking github.com links, to avoid rate limiting [env: GITHUB_TOKEN] --skip-missing Skip missing input files (default is to error if they don't exist) --include-verbatim Find links in verbatim sections like `pre`- and `code` blocks --glob-ignore-case Ignore case when expanding filesystem path glob inputs -o, --output

Output file of status report -f, --format Output format of final status report (compact, detailed, json, markdown) [default: compact] --require-https When HTTPS is available, treat HTTP links as errors --cookie-jar Tell lychee to read cookies from the given file. Cookies will be stored in the cookie jar and sent with requests. New cookies will be stored in the cookie jar and existing cookies will be updated -h, --help Print help (see a summary with '-h') -V, --version Print version ``` ### Exit codes - `0` for success (all links checked successfully or excluded/skipped as configured) - `1` for missing inputs and any unexpected runtime failures or config errors - `2` for link check failures (if any non-excluded link failed the check) - `3` for errors in the config file ### Ignoring links You can exclude links from getting checked by specifying regex patterns with `--exclude` (e.g. `--exclude example\.(com|org)`). If a file named `.lycheeignore` exists in the current working directory, its contents are excluded as well. The file allows you to list multiple regular expressions for exclusion (one pattern per line). For excluding files/directories from being scanned use `lychee.toml` and `exclude_path`. ```toml exclude_path = ["some/path", "*/dev/*"] ``` ### Caching If the `--cache` flag is set, lychee will cache responses in a file called `.lycheecache` in the current directory. If the file exists and the flag is set, then the cache will be loaded on startup. This can greatly speed up future runs. Note that by default lychee will not store any data on disk. ## Library usage You can use lychee as a library for your own projects! Here is a "hello world" example: ```rust use lychee_lib::Result; #[tokio::main] async fn main() -> Result<()> { let response = lychee_lib::check("https://github.com/lycheeverse/lychee").await?; println!("{response}"); Ok(()) } ``` This is equivalent to the following snippet, in which we build our own client: ```rust use lychee_lib::{ClientBuilder, Result, Status}; #[tokio::main] async fn main() -> Result<()> { let client = ClientBuilder::default().client()?; let response = client.check("https://github.com/lycheeverse/lychee").await?; assert!(response.status().is_success()); Ok(()) } ``` The client builder is very customizable: ```rust, ignore let client = lychee_lib::ClientBuilder::builder() .includes(includes) .excludes(excludes) .max_redirects(cfg.max_redirects) .user_agent(cfg.user_agent) .allow_insecure(cfg.insecure) .custom_headers(headers) .method(method) .timeout(timeout) .github_token(cfg.github_token) .scheme(cfg.scheme) .accepted(accepted) .build() .client()?; ``` All options that you set will be used for all link checks. See the [builder documentation](https://docs.rs/lychee-lib/latest/lychee_lib/struct.ClientBuilder.html) for all options. For more information, check out the [examples](examples) folder. ## GitHub Action Usage A GitHub Action that uses lychee is available as a separate repository: [lycheeverse/lychee-action](https://github.com/lycheeverse/lychee-action) which includes usage instructions. ## Contributing to lychee We'd be thankful for any contribution. \ We try to keep the issue tracker up-to-date so you can quickly find a task to work on. Try one of these links to get started: - [good first issues](https://github.com/lycheeverse/lychee/issues?q=is%3Aissue+is%3Aopen+label%3A%22good+first+issue%22) - [help wanted](https://github.com/lycheeverse/lychee/issues?q=is%3Aissue+is%3Aopen+label%3A%22help+wanted%22) For more detailed instructions, head over to [`CONTRIBUTING.md`](/CONTRIBUTING.md). ## Debugging and improving async code Lychee makes heavy use of async code to be resource-friendly while still being performant. Async code can be difficult to troubleshoot with most tools, however. Therefore we provide experimental support for [tokio-console](https://github.com/tokio-rs/console). It provides a top(1)-like overview for async tasks! If you want to give it a spin, download and start the console: ```sh git clone https://github.com/tokio-rs/console cd console cargo run ``` Then run lychee with some special flags and features enabled. ```sh RUSTFLAGS="--cfg tokio_unstable" cargo run --features tokio-console -- ... ``` If you find a way to make lychee faster, please do reach out. ## Troubleshooting and Workarounds We collect a list of common workarounds for various websites in our [troubleshooting guide](./docs/TROUBLESHOOTING.md). ## Users - https://github.com/InnerSourceCommons/InnerSourcePatterns - https://github.com/opensearch-project/OpenSearch - https://github.com/ramitsurana/awesome-kubernetes - https://github.com/papers-we-love/papers-we-love - https://github.com/pingcap/docs - https://github.com/microsoft/WhatTheHack - https://github.com/Azure/ResourceModules - https://github.com/nix-community/awesome-nix - https://github.com/balena-io/docs - https://github.com/launchdarkly/LaunchDarkly-Docs - https://github.com/pawroman/links - https://github.com/analysis-tools-dev/static-analysis - https://github.com/analysis-tools-dev/dynamic-analysis - https://github.com/mre/idiomatic-rust - https://github.com/bencherdev/bencher - https://github.com/lycheeverse/lychee (yes, the lychee docs are checked with lychee 🤯) If you are using lychee for your project, **please add it here**. ## Credits The first prototype of lychee was built in [episode 10 of Hello Rust](https://hello-rust.show/10/). Thanks to all GitHub and Patreon sponsors for supporting the development since the beginning. Also, thanks to all the great contributors who have since made this project more mature. ## License lychee is licensed under either of - Apache License, Version 2.0, (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0) - MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT) at your option.

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