URL shorteners and URL unshorteners- cut it out and see it through

URL Shorteners

URL shortening is a technique allowing to transform the URL of a page, making it shorter but still directing to the original page. This is done by redirecting the connection (HTTP Redirect) to a page having a shorter domain name, which links to the original webpage.

 Some shortening services

• Bit.ly: it's one of the most popular and allows to keep track of the shortened links you created by using bitmarks (i.e. shortened bookmarks), that can be accessed from anywhere;

•  Goo.gl: Google's official shortener, which features simple statistics and analytics to see how many clicks your links are getting;

• TinyUrl: It's very well-known and simple to use, and allows shortened customized URLs, instead of ordinary random shortened URLs. This shortener can also be activated with a click by installing a Firefox add-on;

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• Su.pr: StumbleUpon's official shortener, which allows you both to shorten links and to track traffic, retweets, clicks and more;

• ReduceLnk: This site is more than a URL shortener, because it pays you when you share your links (if you choose to insert ads to your links and they get clicked).

•  t.co: Twitter's official shortener, automatically used to shorten links (if they're expressed in a long form). It can't be used as a stand-alone URL shortening service, but being built-in to Twitter.com makes it an attractive option for many users. 

Why URL shorteners

They've grown popular on Twitter, because a tweet can't be longer than 140 characters. Over time they've become mandatory on several social platforms, because shortened URLs leave more characters available for adding comments, hashtags or retweeting.

Pros

• They can make a link more intriguing;
• They can track links;
• They can hide the original URL, when revealing it could be inappropriate for several reasons (professional, personal, etc.).

Cons

• URL shorteners can be utilized for spam or abuses, as they guarantee a certain anonymity;
• For this reason, some websites prevent shortened URLs from being posted (e.g. StumbleUpon).

URL Unshorteners

URL unshorteners do the opposite of what URL shorteners do. They utilize scripts and algorithms able to reveal what is the actual webpage hiding behind a shortened URL. They can be very useful because, as I've explained in a previous post, shortened URLs are often used by spammers and hackers to redirect you to malicious web sites to gain access to your computer or steal your personal/financial information. Shortened URLs are usually embedded in emails received through Twitter or other services and are very hard to figure out and track down because they don't supply any clue about the identity of who's behind them. They are formed by random or customized characters, not related to a domain name or a company.

Some unshortening services

• Url Unshortener: Unshortens URLs generated by Bit.ly, Goo.gl or TinyURL.

•  Check Short URL: Supports most shortening sites, supplies statistics and suggests security services (such as WOT, SiteAdvisor, Google, Sucuri, Norton or Browser Defender) to detect malicious links.

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• Unshort.me: Supports most shortening services, including fb.me (Facebook).

•  Unshorten.it: Expands the shortened URL and checks whether it's a safe or malicious page. The programmers developed a Firefox add-on, too;

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•  UnShortenEmAll: Expands URLs in Twitter and Identica when you hover over the shortened URL with your mouse.

•  vURL Online: This is a security tool, rather than a simple URL Unshortener, which "quickly and safely dissects malicious or suspect websites". It allowed me to detect a malicious link I had been emailed by one of my Twitter connections (see here for more details).

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Wrap-up

URL Shorteners are very useful to share contents on social media, especially for bloggers, but can be used for malicious purposes by spammers and hackers because they guarantee a virtual anonymity to their users.
URL Unshorteners help users check on the security level of a shortened URL and some of them can detect if the actual webpage behind it has been blacklisted as affected by malware.