Animated graphic to indicate background action is being performed
A throbber, also known as a loading icon, is an animatedgraphical control element used to show that a computer program is performing an action in the background (such as downloading content, conducting intensive calculations or communicating with an external device).[1][2][3] In contrast to a progress bar, a throbber does not indicate how much of the action has been completed.
History
An early use of a throbber occurred in the NCSA Mosaic web browser of the early 1990s, which featured an NCSA logo that animated while Mosaic downloaded a web page. As the user could still interact with the program, the pointer remained normal (and not a busy symbol, such as an hourglass); therefore, the throbber provided a visual indication that the program was performing an action.
The Netscape web browser also featured a throbber. In version 1.0 of Netscape, this took the form of a big blue "N" (Netscape's logo at the time). The animation depicted the "N" expanding and contracting – hence the name "throbber".[4]
The IBM WebExplorer offered a webpage the opportunity to change the look and the animation of the throbber by using proprietary HTML code.[5]
Throbbers also appear in client side applications (such as Ajaxweb apps) where an application within the web browser would wait for some operation to complete. Most of these throbbers appear as a "spinning wheel", which typically consist of 8, 10, or 12 part-radial lines or discs arranged in a circle, as if on a clock face, highlighted in turn as if a wave is moving clockwise around the circle.
In text user interfaces and command lines, the spinning wheel is commonly replaced by a fixed-width character which is cycled through discrete states, such as "|", "/", "-" and "\", which act as the frames of a looping animation-like effect. Unlike graphical activity indicators, this style of throbber is commonly paired with a progress display like a bar, since the lower effective resolution of character-based progress bars can benefit from a separate indication of activity. Often, the spinner is displayed at or near the position of the typing cursor, then called a "spinning cursor" or "rotating cursor". This style of throbber dates from versions of UNIX appearing in the latter 1970s, and DR-DOS utilities in the 1980s, since it requires at least a character-cell addressable display—i.e. one which can be updated quickly to make precise changes to already displayed text—but given that is otherwise simple to program.
^Branwyn, Gareth (May 1997). Jargon Watch: A Pocket Dictionary for the Jitterati. San Francisco: Hardwired. ISBN978-1-888869-06-4. LCCN97174475. OCLC37029057. OL774188M. Retrieved 15 January 2025 – via Internet Archive. p. 149: Animated icons that are used to replace the "meteor shower" icon in Netscape Navigator. Taken from the nickname given to the original Netscape logo, which appeared to throb during document transfers. New icons, such as the J. R. "Bob" Dobbs throbber, are currently traded over the Net.
^Kowalski, Steve (2 September 2022). "Spinning Wheel". khtheat.com. Archived from the original on 3 August 2024. Retrieved 14 January 2025. Netscape, which soon overtook Mosaic as the market-leading web browser, featured a throbber. In version 1.0 of Netscape, this took the form of a big blue "N" (Netscape's logo at the time). The animation depicted the "N" expanding and contracting – hence the name "throbber" (now you know!!). When Netscape unveiled its new logo (a different "N" on top of a hill), they held a competition to find an animation for it. The winning design (featuring the new-look "N" in a meteor shower) became very well-known and almost became an unofficial symbol of the World Wide Web Later. Internet Explorer's blue "e" enjoyed similar status, though it only functioned as a throbber in early versions of the browser.