Out of all the major browsers, only Opera has a fully working implementation that is enabled by default. All other browsers HTTP pipelining is disabled or not implemented.
- Internet Explorer 8 does not pipeline requests, due to concerns regarding buggy proxies and head-of-line blocking.
- Mozilla browsers (such as Mozilla Firefox, SeaMonkey and Camino) support pipelining, however it is disabled by default. Pipelining is disabled by default to avoid issues with misbehaving servers.When pipelining is enabled, Mozilla browsers use some heuristics, especially to turn pipelining off for older IIS servers.
- Konqueror 2.0 supports pipelining, but it’s disabled by default.
- Google Chrome does not support pipelining in the stable release but it is currently in unstable builds and Chromium as a launch parameter.