A
dead link (also called a
broken link or
dangling link) is a link on the
World Wide WebThe World Wide Web is a system of interlinked hypertext documents accessed via the Internet. With a web browser, one can view Web pages that may contain text, images, videos, and other multimedia and navigate between them using hyperlinks...
that points to a
web pageA webpage or web page is a document or resource of information that is suitable for the World Wide Web and can be accessed through a web browser and displayed on a computer screen....
or
serverA server is an application running on a computer that delivers a service. For example, a web server will deliver web pages when requested by a browser . The way a server and a client dialogs is called a protocol...
that is permanently unavailable. The most common result of a dead link is a 404 error, which indicates that the web server responded, but the specific page could not be found. The browser may also return a
DNSThe Domain Name System is a hierarchical naming system for computers, services, or any resource connected to the Internet or a private network. It associates various information with domain names assigned to each of the participants...
error indicating that a web server could not be found at that
domain nameA domain name is an identification label that defines a realm of administrative autonomy, authority, or control in the Internet, based on the Domain Name System ....
.
A
dead link (also called a
broken link or
dangling link) is a link on the
World Wide WebThe World Wide Web is a system of interlinked hypertext documents accessed via the Internet. With a web browser, one can view Web pages that may contain text, images, videos, and other multimedia and navigate between them using hyperlinks...
that points to a
web pageA webpage or web page is a document or resource of information that is suitable for the World Wide Web and can be accessed through a web browser and displayed on a computer screen....
or
serverA server is an application running on a computer that delivers a service. For example, a web server will deliver web pages when requested by a browser . The way a server and a client dialogs is called a protocol...
that is permanently unavailable. The most common result of a dead link is a 404 error, which indicates that the web server responded, but the specific page could not be found. The browser may also return a
DNSThe Domain Name System is a hierarchical naming system for computers, services, or any resource connected to the Internet or a private network. It associates various information with domain names assigned to each of the participants...
error indicating that a web server could not be found at that
domain nameA domain name is an identification label that defines a realm of administrative autonomy, authority, or control in the Internet, based on the Domain Name System ....
. A link might also be dead because of some form of blocking such as content filters or
firewallsA firewall is a part of a computer system or network that is designed to block unauthorized access while permitting authorized communications...
.
Another type of dead link is a
URLIn computing, a Uniform Resource Locator is a subset of the Uniform Resource Identifier that specifies where an identified resource is available and the mechanism for retrieving it. In popular usage and in many technical documents and verbal discussions it is often incorrectly used as a synonym...
that points to a site unrelated to the content sought. This can sometimes occur when a
domain nameA domain name is an identification label that defines a realm of administrative autonomy, authority, or control in the Internet, based on the Domain Name System ....
is allowed to lapse, and is subsequently reregistered by another party. Domain names acquired in this manner are attractive to those who wish to take advantage of the stream of unsuspecting surfers that will inflate hit counters and
PageRankPageRank is a link analysis algorithm, named after Larry Page, used by the Google Internet search engine that assigns a numerical weighting to each element of a hyperlinked set of documents, such as the World Wide Web, with the purpose of "measuring" its relative importance within the set...
ing.
Link rotLink rot is the process by which links on a website gradually become irrelevant or broken as time goes on, because websites that they link to disappear, change their content, or move to new locations....
is the process by which links on a website gradually become irrelevant or broken over time as sites they link to disappear, change content, or redirect to new locations.
Links specially crafted to not resolve, as a type of
memeA meme is a postulated unit or element of cultural ideas, symbols or practices, and is transmitted from one mind to another through speech, gestures, rituals, or other imitable phenomena...
, are known as
Zangelding, which roughly translated from German means
tangle thing. A
zangelding is basically a list of self referencing broken links.
Dead links commonplace on the
InternetThe Internet is a global system of interconnected computer networks that use the standardized Internet Protocol Suite to serve billions of users worldwide...
can also occur on the authoring side, when website content is assembled, copied, or deployed without properly verifying the targets, or simply not kept up to date. Because broken links are to some very annoying, generally disruptive to the user experience, and can live on for many years, sites containing them are regarded as unprofessional.
Solutions to broken links
Due to the unprofessional image that dead links bring to both sites linking and linked to, there are multiple solutions that are available to tackle them - some working to prevent them in the first place, and others trying to resolve then when they have occurred.
- The most obvious form of link management, is employing link checking software that test each link on a website for its validity. An example of, and one of the most widely used link checkers is Xenu's Link Sleuth
Xenu, or Xenu's Link Sleuth, is a computer program that checks websites for broken hyperlinks. It is written by Tilman Hausherr and is proprietary software available at no charge. The program is named after Xenu, the Galactic Ruler from Scientology scripture.-Format:Link Sleuth runs on Microsoft...
.
- Content Managment Systems
A web-content-management system is content management system software, implemented as a Web application, for creating and managing HTML content. It is used to manage and control a large, dynamic collection of Web material...
often offer inbuilt solutions to the management of links, eg. links are updated when content is changed or moved on the site.
- Permalinking
A permalink, or permanent link, is a URL that points to a specific blog or forum entry after it has passed from the front page to the archives. Because a permalink remains unchanged indefinitely, it is less susceptible to link rot. Most modern weblogging and content-syndication software systems...
stops broken links by guaranteeing that the content will never move. Another form of permalinking is linking to a permalink that then redirects to the actual content, ensuring that even though the real content may be moved etc..., links pointing to the resources stay intact.
- The Wayback Machine, operated by the Internet Archive
The Internet Archive is a nonprofit organization dedicated to building and maintaining a free and openly accessible online digital library, including an archive of the World Wide Web....
, keeps historical snapshotsIn computer file systems, a snapshot is a copy of a set of files and directories as they were at a particular point in the past. The term was coined as an analogy to that in photography.- Rationale :...
of websites. If a dead link is found, a search for the webpage on the Wayback Machine may yield a past version, which may be used to replace the dead link with an archived version.
When a broken link remains however, as is very common on the internet (especially between websites due to the difficulty of updating other websites linking to one's own), the visitor that clicks the dead link will get an
HTTP 404The 404 or Not Found error message is a HTTP standard response code indicating that the client was able to communicate with the server but the server could not find what was requested. 404 errors should not be confused with "server not found" or similar errors, in which a connection to the...
error, indicating the resource could not be found. The following tools try to rectify this error:
- The Linkgraph widget get the URL of the correct page based upon the old broken URL by using historical location information.
- The Google 404 Widget employs Google technology to 'guess' the correct URL, and also provides the user a Google search box to find the correct page.
- DeadURL.com gathers and ranks alternate urls for a broken link using Google Cache, the Internet Archive, and user submissions. Typing deadurl.com/ left of a broken link in the browser's address bar and pressing enter loads a ranked list of alternate urls, or (depending on user preference) immediately forwards to the best one.
See also
- Link rot
Link rot is the process by which links on a website gradually become irrelevant or broken as time goes on, because websites that they link to disappear, change their content, or move to new locations....
- Permalink
A permalink, or permanent link, is a URL that points to a specific blog or forum entry after it has passed from the front page to the archives. Because a permalink remains unchanged indefinitely, it is less susceptible to link rot. Most modern weblogging and content-syndication software systems...
- Internet Archive
The Internet Archive is a nonprofit organization dedicated to building and maintaining a free and openly accessible online digital library, including an archive of the World Wide Web....
- WebCite
WebCite is a service that archives web pages on demand. Authors can subsequently cite the archived web pages through WebCite, in addition to citing the original URL of the web page. Readers are able to retrieve the archived web pages indefinitely, without regard to whether the original web page is...
- Slashdot effect
The Slashdot effect, also known as slashdotting, occurs when a popular website links to a smaller site, causing a massive increase in traffic. This overloads the smaller site, causing it to slow down or even temporarily close. The name stems from the huge influx of web traffic that results from...
External links