python system_error ai_generated true

OSError: [Errno 98] Address already in use

ID: python/starlette-uvicorn-address-already-in-use

Also available as: JSON · Markdown · 中文
80%Fix Rate
90%Confidence
0Evidence
2024-01-15First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
0.30+ active — — —

Root Cause

A previous server process is still bound to the port (e.g., uvicorn --reload left a zombie, or another app holds 8000).

generic

中文

之前的服务器进程仍占用该端口（如 uvicorn --reload 遗留僵尸进程，或其他应用占用 8000）。

Workarounds

  1. 97% success 
    lsof -i :8000 | awk 'NR>1{print $2}' | xargs kill -9
# Windows:
netstat -ano | findstr :8000
  2. 95% success 
    uvicorn main:app --port 8001

Dead Ends

Common approaches that don't work:

  1. 60% fail

    Zombie process survives terminal close.

  2. 90% fail

    uvicorn already sets it; a live listener still blocks.