The Google URL Shortener at goo.gl is a service that takes long URLs and squeezes them into fewer characters to make a link easier to share, tweet, or email to friends. For example, the short URL http://goo.gl/l6MS is a convenient shorthand representation for the long URL http://googleblog.blogspot.com/2009/12/making-urls-shorter-for-google-toolbar.html.

After reading this article, if you still have questions about the Google URL Shortener and want to learn more, or would like to give us your feedback, see the Google URL shortener discussion group.

How do I use the Google URL Shortener?
Go to goo.gl and paste the long URL you wish to shorten into the input box at the top of the page. Click "Shorten" and to the right of the box you?ll see a short goo.gl URL that can be copied and pasted anywhere you?d like to share it.

If you?d like to track the analytics of your shortened URL, please sign in to your Google Account before shortening your URL. Your shortened URL will automatically be added to your goo.gl history.

Why use the Google URL Shortener?
People share a lot of links online. This is particularly true as microblogging services such as Twitter and Google Buzz have grown in popularity. With character limits in tweets, status updates, and other modes of short form publishing, a shorter URL leaves more room to say what's on your mind.

Our primary goal in making this service publicly available to all users is to harness Google?s global production infrastructure to provide users with the following benefits:

?Stability - reliable service with good uptime
?Security - warning message if the short URL points to a suspected malware, phishing, or spam website
?Speed - fast resolution of short URLs (in a few milliseconds)

Features
Goo.gl short URLs are randomly generated, and the mappings of short URLs to long URLs are publicly accessible. Additionally, the short URL to long URL mappings are:

?Immutable - once created by you, no one else can change them
?Irrevocable - once created, they do not expire. Note, however, that Google reserves the right to remove any goo.gl short URL, for example for spam, security or legal reasons
Learn more
To learn more about the details on the Google URL Shortener, click one of the links below.

Why do multiple goo.gl short URLs point to the same long URL?
 
People share lots of links and frequently share the same content multiple times, often to measure their viral impact across various platforms like Twitter, Google Buzz, etc. In such cases, people may prefer to share a different short URL each time for easier tracking.
The Google URL Shortener provides different functionality based on whether or not you are signed in:
?If you are signed in to goo.gl using a Google Account, a unique short URL is generated each time a long URL is shortened.?If you are not signed in to goo.gl, the same short URL is reused each time a long URL is shortened, across multiple users.
Where can I view the short URLs created by me?
 
If you are signed in to goo.gl using a Google Account, the short URL to long URL mappings you create are stored in your goo.gl short URL history.
All goo.gl short URLs in your history can subsequently be viewed (sorted by time) on the goo.gl home page if you are signed in.
The short URL history is not publicly accessible and requires appropriate authentication using a Google Account.

How can goo.gl short URLs be tracked for analytics?
 
The Google URL Shortener provides analytics tracking for all short URLs. To access your short URL?s analytics, just add ".info" after any short URL. For example, detailed analytics for http://goo.gl/l6MS is available at http://goo.gl/l6MS.info.
The Google URL Shortener currently reports short URL click analytics across various categories. The different analytics categories currently available include the raw click counts, and their distribution across referrers, browsers, platforms, and geographical locations. Additionally, you can slice this data across different time periods.
Analytics for all goo.gl short URLs are publicly visible to all users.

What are the privacy implications of using the Google URL Shortener?
 
The Google URL Shortener provides the following safeguards to address user privacy concerns:
?The goo.gl short URLs do not publicly reveal the identity of the user who created that URL mapping.?The goo.gl short URL history for a user is accessible only when signed in using that Google Account.?The analytics for all goo.gl short URLs are displayed in aggregate.

http://goo.gl/5PmqV