What is slug?
Some systems define a slug as the part of a URL that identifies a page in human-readable keywords. It is usually the end part of the URL, which can be interpreted as the name of the resource, similar to the basename in a filename or the title of a page. The name is based on the use of the word slug in the news media to indicate a short name given to an article for internal use.
Slugs are typically generated automatically from a page title but can also be entered or altered manually, so that while the page title remains designed for display and human readability, its slug may be optimized for brevity or for consumption by search engines, as well as providing recipients of a shared bare URL with the rough idea of the page’s topic. Long page titles may also be truncated to keep the final URL to a reasonable length.
Slugs may be entirely lowercase, with accented characters replaced by letters from the Latin script and whitespace characters replaced by a hyphen or an underscore to avoid being encoded. Punctuation marks are generally removed, and some also remove short, common words such as conjunctions. For example, the title This, That, and the Other! An Outré Collection could have a generated slug of
Another benefit of URL slugs is the facilitated ability to find a desired page out of a long list of URLs without page titles, such as a minimal list of opened tabs exported using a browser extension, and the ability to preview the approximate title of a target page in the browser if hyperlinked to without title.
Web sites that make use of slugs include Stack Exchange Network with question title after slash, and Instagram with
?taken-by=username URL parameter.
The documentation uses material from the Wikipedia article “Clean URL”, which are released under the Creative Commons Attribution-Share-Alike License 3.0.