Internet users are distributed throughout the world using a wide variety of languages and alphabets and expect to be able to create URLs in their own local alphabets. An Internationalized Resource Identifier (IRI) is a form of URL that includes Unicode characters. All modern browsers support IRIs. The parts of the URL requiring special treatment for different alphabets are the domain name and path.
The domain name in the IRI is known as an Internationalized Domain Name (IDN). Web and Internet software automatically convert the domain name into punycode usable by the Domain Name System; for example, the Chinese URL //例子.卷筒纸 becomes //xn--fsqu00a.xn--3lr804guic/. The indicates that the character was not originally ASCII.
The URL path name can also be specified by the user in the local writing system. If not already encoded, it is converted to UTF-8, and any characters not part of the basic URL character set are escaped as hexadecimal using percent-encoding; for example, the Japanese URL //example.com/引き割り.html becomes //example.com/%E5%BC%95%E3%81%8D%E5%89%B2%E3%82%8A.html. The target computer decodes the address and displays the page.
A redirect service is an information management system, which provides an internet link that redirects users to the desired content. The typical benefit to the user is the use of a memorable domain name, and a reduction in the length of the URL or web address. A redirecting link can also be used as a permanent address for content that frequently changes hosts, similarly to the Domain Name System. Hyperlinks involving URL redirection services are frequently used in spam messages directed at blogs and wikis. Thus, one way to reduce spam is to reject all edits and comments containing hyperlinks to known URL redirection services; however, this will also remove legitimate edits and comments and may not be an effective method to reduce spam. Recently, URL redirection services have taken to using AJAX as an efficient, user friendly method for creating shortened URLs. A major drawback of some URL redirection services is the use of delay pages, or frame based advertising, to generate revenue.
A few well-known websites have set up their own URL shortening services for their own use – for example, Twitter with t.co, Google with g.co, and GoDaddy with x.co.
Some websites create short links to make sharing links via instant messaging easier, and to make it cheaper to send them via SMS. This can be done online, at the web pages of a URL shortening service; to do it in batch or on demand may require the use of an API.
A Uniform Resource Locator (URL), colloquially termed a web address, is a reference to a web resource that specifies its location on a computer network and a mechanism for retrieving it. A URL is a specific type of Uniform Resource Identifier (URI), although many people use the two terms interchangeably. URLs occur most commonly to reference web pages (http), but are also used for file transfer (ftp), email (mailto), database access (JDBC), and many other applications.
Most web browsers display the URL of a web page above the page in an address bar. A typical URL could have the form //www.example.com/index.html, which indicates a protocol , a hostname , and a file name.
A web browser will usually dereference a URL by performing an HTTP request to the specified host, by default on port number 80. URLs using the scheme require that requests and responses be made over a secure connection to the website.
Every HTTP URL conforms to the syntax of a generic URI.
There was only a URL builder module in this category. Pipes needed to have URLs of RSS to get the content. This URL builder enabled users to create URLs instead of typing the URL address. It used a base URL and query parameters to generate other URLs.
A URL will often comprise a path, script name, and query string. The query string parameters dictate the content to show on the page, and frequently include information opaque or irrelevant to users—such as internal numeric identifiers for values in a database, illegibly-encoded data, session IDs, implementation details, and so on. Clean URLs, by contrast, contain only the path of a resource, in a hierarchy that reflects some logical structure that users can easily interpret and manipulate.
There are several techniques to implement a URL shortening. Keys can be generated in base 36, assuming 26 letters and 10 numbers. In this case, each character in the sequence will be 0, 1, 2, ..., 9, a, b, c, ..., y, z. Alternatively, if uppercase and lowercase letters are differentiated, then each character can represent a single digit within a number of base 62 (26 + 26 + 10). In order to form the key, a hash function can be made, or a random number generated so that key sequence is not predictable. Or users may propose their own custom keys. For example, can be shortened to.
Short URLs often circumvent the intended use of top-level domains for indicating the country of origin; domain registration in many countries requires proof of physical presence within that country, although a redirected URL has no such guarantee.
URL redirection, also called URL forwarding, is a World Wide Web technique for making a web page available under more than one URL address. When a web browser attempts to open a URL that has been redirected, a page with a different URL is opened. Similarly, domain redirection or domain forwarding is when all pages in a URL domain are redirected to a different domain, as when wikipedia.com and wikipedia.net are automatically redirected to wikipedia.org.
Netscape introduced the meta refresh feature which refreshes a page after a certain amount of time. This can specify a new URL to replace one page with another. This is supported by most web browsers. A timeout of zero seconds effects an immediate redirect. This is treated like a 301 permanent redirect by Google, allowing transfer of PageRank to the target page.
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. On 30 March 2018 Google announced that it is "turning down support for goo.gl over the coming weeks and replacing it with Firebase Dynamic Links" (although existing goo.gl links will continue to function).
A major crime associated with Spoofed URLs is identity theft. The thief will make a Spoofed URL website that is similar to the website the user is trying to go to, and when taken to the webpage, it will look nearly identical. Then, if the user is shopping and enters all of their information to pay for the items, they inadvertently give the thief their credit card and identity information. The websites will post products at “too good to be true” prices, and lure those who are new to the internet and looking for a good deal. Crimes like these happen quite often, and most frequently occur during the heaviest trafficked online shopping period of the year, between the holidays of Thanksgiving and Christmas. Another crime associated with Spoofed URL’s is setting up a fake anti-malware software. An example of this would be Ransomware, a fake anti-malware software that locks up important files for the computer to run, and forces the user to pay a ransom to get the files back. If the user refuses to pay, after a certain period of time, the Ransomware will delete the files off of the computer, essentially causing the computer to crash. These programs usually come up in ads on the side of popular websites, such as dating websites and even social media like Twitter and Facebook. Also, these can come up as attachments in emails tied to phishing. Phishing scams are also another major way that users can get tricked into scams (see below).
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.
Nginx has an integrated http rewrite module, which can be used to perform advanced URL processing and even web-page generation (with the return directive). A showing example of such advanced use of the rewrite module is mdoc.su, which implements a deterministic URL shortening service entirely with the help of nginx configuration language alone.