What’s new in Tornado 6.5.2

Aug 8, 2025

Bug fixes

  • Fixed a bug that resulted in WebSocket pings not being sent at the configured interval.

  • Improved logging for invalid Host headers. This was previously logged as an uncaught exception with a stack trace, now it is simply a 400 response (logged as a warning in the access log).

  • Restored the host argument to HTTPServerRequest. This argument is deprecated and will be removed in the future, but its removal with no warning in 6.5.0 was a mistake.

  • Removed a debugging print statement that was left in the code.

  • Improved type hints for gen.multi.