Tiny, fast & funny HTTP server

Thin is a Ruby web server that glues together 3 of the best Ruby libraries in web history:

  • the Mongrel parser: the root of Mongrel speed and security

  • Event Machine: a network I/O library with extremely high scalability, performance and stability

  • Rack: a minimal interface between webservers and Ruby frameworks

Which makes it, with all humility, the most secure, stable, fast and extensible Ruby web server bundled in an easy to use gem for your own pleasure.

Site: Group: Bugs: Code: IRC: #thin on freenode


For the latest stable version:

sudo gem install thin

Or from source:

git clone git://
cd thin
rake install


A thin script offers an easy way to start your Rails application:

cd to/your/rails/app
thin start

But Thin is also usable with a Rack config file. You need to setup a file and pass it to the thin script:

app = proc do |env|
     'Content-Type' => 'text/html',
     'Content-Length' => '2'

run app

thin start -R

See example directory for more samples and run 'thin -h' for usage.


Ruby License,


The parser was stolen from Mongrel by Zed Shaw. Mongrel Web Server (Mongrel) is copyrighted free software by Zed A. Shaw <zedshaw at zedshaw dot com> You can redistribute it and/or modify it under either the terms of the GPL.

Thin is copyright Marc-Andre Cournoyer <[email protected]>

Get help at Report bugs at and major security issues directly to a team member (see COMMITTERS)