# URLCanonicalize
URLCanonicalize is a Ruby gem that finds the canonical version of a URL. It
provides `canonicalize` methods for the String, URI::HTTP, URI::HTTPS and
Addressable::URI classes.
## Installation
Add this line to your application's Gemfile:
```ruby
gem 'url_canonicalize'
```
## Usage
```ruby
'http://www.twitter.com'.canonicalize # => 'https://twitter.com/'
URI('http://www.twitter.com').canonicalize # => #
Addressable::URI.canonicalize('http://www.twitter.com') # => #
```
## More Information
URLCanonical follows HTTP redirects and also looks for `rel="canonical"` hints
in both the HTTP headers and the `` section of the response HTML. The URL
it returns will be both normalized and canonical. The intention is that
whatever variant of a URL is supplied the result will always be the same. The
intended use case is for applications that need to dedupe a list of URLs, for
instance to check if a new URL is already present in a list. If the list is
built from canonicalized URLs then the resulting set will have fewer URLs that
point to the same ultimate resource.