URL shortening is a technique on the World Wide Web in which a Uniform Resource Locator (URL) may be made substantially shorter in length and still direct to the required page. This is achieved by using a redirect on a domain name that is short, which links to the web page that has a long URL. This is especially convenient for messaging technologies that limit the number of characters that may be used in a message, such as Twitter, and for reducing the amount of typing required if the reader is copying a URL from a print source. In November 2009, the shortened links of the URL shortening service Bitly were accessed 2.1 billion times.
Other uses of URL shortening are to "beautify" a link, track clicks, or disguise the underlying address. Although disguising of the underlying address may be desired for legitimate business or personal reasons, it is open to abuse and for this reason, some URL shortening service providers have found themselves on spam blacklists, because of the use of their redirect services by sites trying to bypass those very same blacklists. Some websites, such as is.gd, prevent short, redirected URLs from being posted.
Other uses of URL shortening are to "beautify" a link, track clicks, or disguise the underlying address. Although disguising of the underlying address may be desired for legitimate business or personal reasons, it is open to abuse and for this reason, some URL shortening service providers have found themselves on spam blacklists, because of the use of their redirect services by sites trying to bypass those very same blacklists. Some websites, such as is.gd, prevent short, redirected URLs from being posted.
History:
a system, method and computer program product for providing links to remotely located information in a network of remotely connected computers. A uniform resource locator (URL) is registered with a server. A shorthand link is associated with the registered URL. The associated shorthand link and URL are logged in a registry database. When a request is received for a shorthand link, the registry database is searched for an associated URL. If the shorthand link is found to be associated with a URL, the URL is fetched, otherwise an error message is returned.
The patent was filed in September 2000; while the patent was issued in 2005, patent applications are made public within 18 months of filing.
Another reference to URL shortening was in 2001.The first notable URL shortening service, TinyURL, was launched in 2002. Its popularity influenced the creation of at least 100 similar websites,although most are simply domain alternatives. Initially Twitter automatically translated long URLs using TinyURL, although it began using bit.ly in 2009.
On 14 August 2009 WordPress announced the wp.me URL shortener for use when referring to any WordPress.com blog post. In November 2009, shortened links on bit.ly were accessed 2.1 billion times. Around that time, bit.ly and TinyURL were the most widely used URL-shortening services.
One service, tr.im, stopped generating short URLs in 2009, blaming a lack of revenue-generating mechanisms to cover costs and Twitter's default use of the bit.ly shortener, and questioning whether other shortening services could be profitable from URL shortening in the longer term. It resumed for a time,then closed.
The shortest possible long-term URLs were generated by NanoURL from December 2009 until about 2011, associated with the top-level .to (Tonga) domain, in the form http://to./xxxx, where xxxx represents a sequence of random numbers and letters.
On 14 December 2009 Google announced a service called Google URL Shortener at goo.gl, which originally was only available for use through Google products (such as Google Toolbar and FeedBurner) and extensions for Google Chrome.On 21 December 2009, Google introduced a YouTube URL Shortener, youtu.be.From September 2010 Google URL Shortener became available via a direct interface. The goo.gl service provides analytics details and a QR code generator.
Advantages:
The main advantage of a short link is that it is, in fact, short, and
can be easily communicated and entered without error. To a very limited
extent it may obscure the destination of the URL, though easily
discoverable; this may be advantageous, disadvantageous, or irrelevant. A
short link which expires, or can be terminated, has some security
advantages.
Abuse:
URL shortening may be utilized by spammers or for illicit internet
activities. As a result, many have been removed from online registries
or shut down by web hosts or internet service providers.
According to Tonic Corporation, the registry for .to domains, it is "very serious about keeping domains spam free" and may remove URL shortening services from their registry if the service is abused.
In addition, "u.nu" made the following announcement upon closing operations:
According to Tonic Corporation, the registry for .to domains, it is "very serious about keeping domains spam free" and may remove URL shortening services from their registry if the service is abused.
In addition, "u.nu" made the following announcement upon closing operations:
The last straw came on September 3, 2010, when the server was disconnected without notice by our hosting provider in response to reports of a number of links to child pornography sites. The disconnection of the server caused us serious problems, and to be honest, the level and nature of the abuse has become quite demoralizing. Given the choice between spending time and money to find a different home, or just giving up, the latter won out.
Linkrot:
The convenience offered by URL shortening also introduces potential
problems, which have led to criticism of the use of these services.
Short URLs, for example, will be subject to linkrot
if the shortening service stops working; all URLs related to the
service will become broken. It is a legitimate concern that many
existing URL shortening services may not have a sustainable business
model in the long term. This worry was highlighted by a statement from
tr.im in August 2009 (see above).In late 2009, the Internet Archive started the "301 Works" projects, together with twenty collaborating companies (initially), whose short URLs will be preserved by the project. The URL shortening service ur1.ca provides its entire database as a
file download, so if its website stops working, other websites may be
able to provide ways to correct broken links to URLs shortened with its
service. A circumvention could be that a website provided its own
shortlinks instead of relying on a shortening service – but this is not
common.
Transnational law:
Shortened internet links typically use foreign country domain names, and are therefore under the jurisdiction of that nation. Libya,
for instance, exercised its control over the .ly domain in October 2010
to shut down vb.ly for violating Libyan pornography laws. Failure to
predict such problems with URL shorteners and investment in URL
shortening companies may reflect a lack of due diligence
Blocking:
Some websites prevent short, redirected URLs from being posted.
In 2009, the Twitter network replaced TinyURL with Bit.ly as its default shortener of links longer than twenty-six characters.In April 2009, TinyURL was reported to be blocked in Saudi Arabia.Yahoo! Answers blocks postings that contain TinyURLs,and Wikipedia does not accept links by any URL shortening services in its articles.
In 2009, the Twitter network replaced TinyURL with Bit.ly as its default shortener of links longer than twenty-six characters.In April 2009, TinyURL was reported to be blocked in Saudi Arabia.Yahoo! Answers blocks postings that contain TinyURLs,and Wikipedia does not accept links by any URL shortening services in its articles.
Advertising:
Sites such as Adf.ly use a number of interstitial advertising techniques to generate revenue. This may deter readers.
Privacy and security:
Users may be exposed to privacy issues through a URL shortening
service's ability to track a user's behavior across many domains.
A short URL obscures the target address and can be used to redirect to an unexpected site. Examples of this are rickrolling, redirecting to shock sites, or to affiliate websites. The short URL can allow blacklisted URLs to be accessed, bypassing blocks; this facilitates redirection of a user to blacklisted scam pages or pages containing malware or XSS attacks. TinyURL tries to disable spam-related links from redirecting. ZoneAlarm, however, has warned its users: "TinyURL may be unsafe. This website has been known to distribute spyware." TinyURL countered this problem by offering an option to view a link's destination before using a shortened URL. This ability is installed on the browser via the TinyURL website and requires the use of cookies. A destination preview may also be obtained by prefixing the word "preview" to the TinyURL URL; for example, the destination of http://tinyurl.com/8kmfp is revealed by entering http://preview.tinyurl.com/8kmfp. Other URL shortening services provide a similar destination display. Security professionals suggest that users check a short URL's destination before accessing it, following an instance where shortening service cli.gs was compromised, exposing millions of users to security uncertainties. There are several web applications that can display the destination of a shortened URL.
Some URL shortening services filter their links through bad-site screening services such as Google Safe Browsing. Many sites that accept user-submitted content block links, however, to certain domains in order to cut down on spam and for this reason, known URL redirection services are often themselves added to spam blacklists.
A short URL obscures the target address and can be used to redirect to an unexpected site. Examples of this are rickrolling, redirecting to shock sites, or to affiliate websites. The short URL can allow blacklisted URLs to be accessed, bypassing blocks; this facilitates redirection of a user to blacklisted scam pages or pages containing malware or XSS attacks. TinyURL tries to disable spam-related links from redirecting. ZoneAlarm, however, has warned its users: "TinyURL may be unsafe. This website has been known to distribute spyware." TinyURL countered this problem by offering an option to view a link's destination before using a shortened URL. This ability is installed on the browser via the TinyURL website and requires the use of cookies. A destination preview may also be obtained by prefixing the word "preview" to the TinyURL URL; for example, the destination of http://tinyurl.com/8kmfp is revealed by entering http://preview.tinyurl.com/8kmfp. Other URL shortening services provide a similar destination display. Security professionals suggest that users check a short URL's destination before accessing it, following an instance where shortening service cli.gs was compromised, exposing millions of users to security uncertainties. There are several web applications that can display the destination of a shortened URL.
Some URL shortening services filter their links through bad-site screening services such as Google Safe Browsing. Many sites that accept user-submitted content block links, however, to certain domains in order to cut down on spam and for this reason, known URL redirection services are often themselves added to spam blacklists.
