A scroll wheel is a computer mouse feature that allows users to quickly move up or down a computer window. Most commonly, it’s made of a rubber-coated plastic disc that’s placed between the left and right mouse buttons so it can be easily accessed by the user’s index finger. Sometimes, the scroll wheel is a metal component with magnetic clicking capabilities that enhance the user experience.
The scroll wheel was first popularized by Microsoft with the release of the Intellimouse device in 1996. As more people began using computers to make spreadsheets, type documents, and browse the Internet, they needed a way to easily navigate large files and pages.
After the success of the Intellimouse, nearly all computer mouse manufacturers began including a scroll wheel — or a similar feature that served the same purpose — in their devices. Some companies have introduced innovations to the scroll wheel hardware, but the majority of computer mice on the market today include some form of a scroll wheel. The placement of the scroll wheel has also changed over time to create more ergonomic devices, but the placement between mouse buttons is the most accessible option for both right- and left-handed users.
Scroll wheels have also appeared on some early mobile devices like Blackberry mobile phones, as well as keyboard models from Logitech and Microsoft. However, these features have largely been replaced by trackballs or touchpads.
A scroll wheel’s basic function is to navigate a document, web page, or application vertically in either direction by rotating the wheel with the finger. Pressing down on the top of a scroll wheel will usually engage a third mouse button that can be customized to execute a specific command, like opening a link in a new window.
A small number of computer mice have two scroll wheels that can each be configured for specialized functions. These kinds of mice are most popular in the PC gaming market because a user can have separate controls for navigating forward and backward as well as zooming in and out from a single view. These more complex gaming mice are highly configurable based on the user’s needs.
Engineers, architects, and designers also use a scroll wheel to navigate their workspace in computer-aided design (CAD) applications. Aside from scrolling up and down and zooming in and out, the scroll wheel can allow the user’s viewpoint to orbit around the object on the screen, or change the active tool.
Advancements in input device technology have made way for numerous scroll wheel alternatives. These include: