A URL shortener is basically a way to make a long URL (Uniform Resource Locator) shorter. URL shortening services are Web tools (or services) that allow you to provide a long URL to a specific webpage and obtain a much shorter URL from the service provider.
One of the most common reasons why people want a short URL is to save character space when typing messages on Twitter and other microblogging sites. These sites limit the number of characters you can use in an update and a long URL means less space for a message.
Another good reason to use a URL shortener is when you have a lengthy and unattractive URL on an ISP or free Web hosting service. In some cases you can use a shortener to have a more pleasing Web address. Short URLs are also useful when sharing an extremely long URL over instant messaging or in email where there is a chance the long link could be broken during message transmission.
Others may want to use a short URL to hide the originating domain name when posting a URL. This can be for legitimate reasons, but unfortunately this is a feature of short URLs that is frequently abused by spammers.
A URL shortener works because of a Web server function called a “Redirect” (URL redirection). Basically the new URL (the short URL) will redirect users to the old URL (your long URL). When you enter a URL a browser, this actually sends an HTTP command to the Web server directing it to fetch and transmit the requested Web page. There are a series of redirect HTTP response codes that a server can return, including the following:
- 301: (permanent) Returns a permanent redirect status indicating that the resource has moved permanently.
- 302: (temp) Returns a temporary redirect status.
- 303: (see other) Returns a "See Other" status indicating that the resource has been replaced.
Webopedia's Twitter Dictionary page has a lengthy URL. If we want to post a link to this page on Twitter we would use a URL shortener to decrease the length of characters in the URL. Using the Bit.ly service you simply enter in the page URL you want to make short and click the "Shorten" button on the Bit.ly homepage.
In this case the resulting short URL is: http://bit.ly/3wMIVa. When a person clicks the http://bit.ly/3wMIVa hyperlink, bit.ly uses a 301 redirect and sends users to the "permanent URL” at http://www.webopedia.com/quick_ref/Twitter_Dictionary_Guide.asp.
While short URLs make it easier to access pages at a long URL, there are a number of things you should consider before using these services, especially when promoting and relying on the short URLs for your Internet business or website.
If the URL shortening service is shut down or goes offline then your short URLs will not work . Service interruptions can happen but you can avoid disruptions by choosing a URL shorten service that has been around for a while and has a good reputation for actively monitoring its service for spam links.
Different URL shortening services use different HTTP redirects. The type of redirect is being used determines where the credit for the URL is given, and you want search engines to credit the short link to your site not the URL shortening site. The services that use a 301 permanent redirect are the best choice.
Short URLs can be used for malicious reasons; for example, to cloak the URL of a pornography website or to hide malicious spyware and downloads. Savvy Internet users simply might not click a short URL. In terms of security, remember that you have no control over the URL shortener service and should they fall victim to malicious hacking so will your short URLs.
Since short URLs can be used for directing users to malicious or spam sites some ISPs and Web sites will block short URLs so these are not seen by users.
Short URLs consist of “meaningless” characters. Users and search engines do not see useful words (keywords) in a short URL. For example our short URL http://bit.ly/3wMIVa tells you nothing about the page you will land on when you click the link. Look for a short URL that you can customize with a keyword.
On the positive side, a URL shortener is useful and commonplace online today. It has disadvantages but it also has many advantages over using a long URL, especially for microblogging. Ultimately, just having a short URL to access your Web page tops the list of advantages, but it can also help with keeping links intact in email or text messages and it can be useful for SEO (search engine optimization) when you use a short URL service that allows you to choose keywords in the short URL.
Another positive note is that most URL shortener services provide detailed tracking and analytics for each shortened URL. This is useful to track how popular the short URL is and to see when it is published on social media sites.
Source : https://www.webopedia.com