Because I had so much trouble finding a good autolinking implementation out in the wild, I decided to roll my own. It seemed that everything I found out there was either an implementation that didn't cover every case, or was just limited in one way or another.

So, this utility attempts to handle everything. It:

• Autolinks URLs, whether or not they start with the protocol (i.e. 'http://'). In other words, it will automatically link the text "google.com", as well as "http://google.com".
• Will properly handle URLs with special characters
• Will properly handle URLs with query parameters or a named anchor (i.e. hash)
• Will autolink email addresses.
• Will autolink Twitter handles.
• Will properly handle HTML input. The utility will not change the href attribute inside anchor (<a>) tags (or any other tag/attribute for that matter), and will not accidentally wrap the inner text of an anchor tag with a new one (which would cause doubly-nested anchor tags).

Hope that this utility helps you as well!

Simply clone or download the zip of the project, and link to either dist/Autolinker.js or dist/Autolinker.min.js with a script tag:

<script src="path/to/Autolinker.min.js"></script>

Can also download via Bower:

bower install Autolinker.js --save

var linkedText = Autolinker.link( textToAutolink[, options] );

Example:

var linkedText = Autolinker.link( "Check out google.com" );
// Produces: "Check out <a href="http://google.com" target="_blank">google.com</a>"

There are options which may be specified for the linking. These are specified by providing an Object as the second parameter to Autolinker.link(). Options include:

• newWindow : Boolean
  true to have the links should open in a new window when clicked, false otherwise. Defaults to true.
• stripPrefix : Boolean
  true to have the 'http://' or 'https://' and/or the 'www.' stripped from the beginning of links, false otherwise. Defaults to true.
• truncate : Number
  A number for how many characters long URLs/emails/twitter handles should be truncated to inside the text of a link. If the URL/email/twitter is over the number of characters, it will be truncated to this length by replacing the end of the string with a two period ellipsis ('..'). Ex: a url like 'http://www.yahoo.com/some/long/path/to/a/file' truncated to 25 characters may look like this: 'yahoo.com/some/long/pat..'
• urls : Boolean
  true to have URLs auto-linked, false to skip auto-linking of URLs. Defaults to true.
• email : Boolean
  true to have email addresses auto-linked, false to skip auto-linking of email addresses. Defaults to true.
• twitter : Boolean
  true to have Twitter handles auto-linked, false to skip auto-linking of Twitter handles. Defaults to true.

For example, if you wanted to disable links from opening in new windows, you could do:

var linkedText = Autolinker.link( "Check out google.com", { newWindow: false } );
// Produces: "Check out <a href="http://google.com">google.com</a>"

And if you wanted to truncate the length of URLs (while also not opening in a new window), you could do:

var linkedText = Autolinker.link( "http://www.yahoo.com/some/long/path/to/a/file", { truncate: 25, newWindow: false } );
// Produces: "<a href="http://www.yahoo.com/some/long/path/to/a/file">yahoo.com/some/long/pat..</a>"

One could update an entire DOM element that has unlinked text to auto-link them as such:

var myTextEl = document.getElementById( 'text' );
myTextEl.innerHTML = Autolinker.link( myTextEl.innerHTML );

• Added options for granular control of which types are linked (urls, email addresses, and/or twitter handles). (thanks @aziraphale)

• Simplified the path / query string / hash processing into a single regular expression instead of 3 separate ones.
• Added support for parenthesis in URLs, such as: en.wikipedia.org/wiki/IANA_(disambiguation) (thanks @dandv)
• Add all known top-level domains (TLDs) (thanks @wouter0100)

Merged pull requests from @afeld:

• strip protocol and 'www.' by default - fixes #1
• truncate URLs from the end
• make simpler regex for detecting prefix
• remove trailing slashes from URLs, and handle periods at the end of paths
• re-use domain+TLD regexes for email matching
• add .me and .io to list of TLDs

Thanks Aidan :)

• Fixed an issue with handling nested HTML tags within anchor tags.

• Implemented the truncate option.

• Implemented autolinking Twitter handles.

• Initial implementation, which autolinks URLs and email addresses. Working on linking Twitter handles.