A fast, async, resource-friendly link checker written in Rust. \ For GitHub links, it can optionally use a GITHUB_TOKEN to avoid getting blocked by the rate limiter.

Lychee demo

Features

This comparison is made on a best-effort basis. Please create a PR to fix outdated information. use | | 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] | | 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] | | Recursion | ![no] | ![no] | ![no] | ![yes] | ![yes] | ![yes] | ![yes] | ![no] | | Amazing lychee logo | ![yes] | ![no] | ![no] | ![no] | ![no] | ![no] | ![no] | ![no] |

¹ Other machine-readable formats like CSV are supported.

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:

Using the Commandline Client

You can run lychee directly from the commandline.

Installation

Using cargo

cargo install lychee

Using the official Docker image

docker pull lycheeverse/lychee

Using pre-built binaries

We provide binaries for Linux, macOS, and Windows for every release. \ You can download them from the releases page.

Commandline usage

Run it inside a repository with a README.md:

lychee

You can also specify various types of inputs:

```

check links on a website:

lychee https://endler.dev/

check links in a remote file:

lychee https://raw.githubusercontent.com/lycheeverse/lychee/master/README.md

check links in local file(s):

lychee README.md lychee test.html info.txt

check links in local files (by 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, displaying progress and check result for each link:

lychee --glob-ignore-case --progress --verbose "~/projects/*/[r]eadme." ```

GitHub token

Optionally, to avoid getting rate-limited while checking GitHub links, you can 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.

The token can be generated in your GitHub account settings page. A personal token with no extra permissions is enough to be able to check public repos links.

Commandline Parameters

There is an extensive list of commandline parameters to customize the behavior, see below for a full list.

``` USAGE: lychee [FLAGS] [OPTIONS] [--] [inputs]...

FLAGS: -E, --exclude-all-private Exclude all private IPs from checking. Equivalent to --exclude-private --exclude-link- local --exclude-loopback --exclude-link-local Exclude link-local IP address range from checking --exclude-loopback Exclude loopback IP address range from checking --exclude-private Exclude private IP address ranges from checking --glob-ignore-case Ignore case when expanding filesystem path glob inputs --help Prints help information -i, --insecure Proceed for server connections considered insecure (invalid TLS) -p, --progress Show progress --skip-missing Skip missing input files (default is to error if they don't exist) -V, --version Prints version information -v, --verbose Verbose program output

OPTIONS: -a, --accept Comma-separated list of accepted status codes for valid links -b, --base-url Base URL to check relative URLs --basic-auth Basic authentication support. E.g. username:password -c, --config Configuration file to use [default: ./lychee.toml] --exclude ... Exclude URLs from checking (supports regex) -f, --format Output file format of status report [default: string] --github-token GitHub API token to use when checking github.com links, to avoid rate limiting [env: GITHUB_TOKEN=] -h, --headers ... Custom request headers --include ... URLs to check (supports regex). Has preference over all excludes --max-concurrency Maximum number of concurrent network requests [default: 128] -m, --max-redirects Maximum number of allowed redirects [default: 10] -X, --method Request method [default: get] -o, --output Output file of status report -s, --scheme Only test links with the given scheme (e.g. https) -T, --threads Number of threads to utilize. Defaults to number of cores available to the system -t, --timeout Website timeout from connect to response finished [default: 20] -u, --user-agent User agent [default: lychee/0.5.0]

ARGS: ... 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 (-). Prefix with -- to separate inputs from options that allow multiple arguments [default: README.md] ```

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)

Library usage

You can use lychee as a library for your own projects. Simply add it as a dependency and build your client:

```rust use http::StatusCode

let client = lychee::ClientBuilder::default().build()?; let url = Url::parse("https://github.com/lycheeverse/lychee")?; let response = client.check(Website(url)).await?; assert!(matches!(response.status, Status::Ok(_))); ```

The client is very customizable, e.g.

rust let client = lychee::ClientBuilder::default() .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) .verbose(cfg.verbose) .github_token(cfg.github_token) .scheme(cfg.scheme) .accepted(accepted) .build()?;

See the builder documentation for all options.

Troubleshooting and workarounds

We collect a list of common workarounds for various websites in our troubleshooting guide.

Users

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/lycheeverse/lychee (yes, the lychee docs are checked with lychee 🤯)

If you are using lychee for your project, we'd be delighted to hear about it.

License

lychee is licensed under either of

Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Credits

The first prototype of lychee was built in episode 10 of Hello Rust. 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.