HTTP/0.9 is the predecessor to HTTP/1.x. One big difference between HTTP/0.9 and HTTP/1.x is that HTTP/0.9 lacks any response headers. So when we send an HTTP/1.x request, if the server responds with a message that doesn't look like HTTP/1.x, we just assume it's an HTTP/0.9 response and treat the entire response is the response body, with no headers. We're removing this behavior except on default ports, and plan to further reduce support in the future.


Established standard

Status in Chromium


Removed (tracking bug) in:

  • Chrome for desktop release 55
  • Chrome for Android release 55
  • Chrome for iOS release 55
  • Android WebView release 55

Consensus & Standardization

After a feature ships in Chrome, the values listed here are not guaranteed to be up to date.

  • No signal
  • No signal
  • Shipped/Shipping
  • No signals


Last updated on 2020-11-09