uvicorn 0.53.0

Version 0.53.0

on Python PyPI

🌐 Opt-in HTTP/2 support

uvicorn 0.53.0 adds experimental HTTP/2 through zttp, alongside a new zuvloop integration and connection-handling improvements.

uv add uvicorn==0.53.0

• Serve HTTP/1.1 and HTTP/2 with zttp (#2982, #3101). Install zttp, then enable HTTP/2 with --http zttp --http2. Uvicorn negotiates HTTP/2 over TLS with ALPN and supports cleartext prior knowledge.
• HTTP/2 remains experimental. Upgrade-based h2c and WebSockets over HTTP/2 are not supported.

⚙️ More event loop choice

• Run Uvicorn with zuvloop (#3104). Install zuvloop separately and select it explicitly with --loop zuvloop on CPython 3.14 or newer.

🛡️ More reliable connections and proxies

• Honor Connection: close token lists (#3103). Uvicorn now parses comma-separated tokens case-insensitively across HTTP implementations.
• Trust IPv6 loopback proxies by default (#3119). The default FORWARDED_ALLOW_IPS value now includes ::1.
• Keep upgraded WebSockets alive (#3107). Uvicorn cancels the HTTP keep-alive timer when the connection becomes a WebSocket.

Full changelog: 0.52.4...0.53.0