Software bloat is a process whereby successive versions of a computer program include an increasing proportion of unnecessary features that are not used by end users, or generally use more system resources than necessary, while offering little or no benefit to its users.

Software developers involved in the industry during the 1970s had severe limitations on disk space and memory. Every byte and clock cycle counted, and much work went into fitting the programs into available resources. Achieving this efficiency was one of the highest values of computer programmers, and the best programs were often called "elegant"—seen as a form of high art.

This situation has now reversed. Resources are perceived as cheap, and rapidity of coding and headline features for marketing are seen as priorities.^[when?] In part, this is because technological advances have since increased processing capacity and storage density by orders of magnitude, while reducing the relative costs by similar orders of magnitude (see Moore's Law). Additionally, the spread of computers through all levels of business and home life has produced a software industry many times larger than it was in the 1970s. Programs are now usually churned out by teams, directed by committees in software factories where each programmer works on only a part of the whole, on one or more subroutine. Thus today; the highest value is often the adherence to a predetermined structure that makes it compliant, with subroutines as interchangeable as piston rods. Inelegant, even sloppy code is to some degree hidden from the end users by the increasing brute force and speed of modern computers. (There is little payoff to say, increasing the speed of a sloppy five-millisecond subroutine, even by a factor of 100.)