# OSError: [Errno 98] Address already in use

- **ID:** `python/starlette-uvicorn-port-in-use`
- **Domain:** python
- **Category:** system_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

Another process (often a previous uvicorn run) is already bound to the target port.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.x | active | — | — |

## Workarounds

1. **** (95% success)
   ```
   lsof -i :8000 | awk 'NR>1 {print $2}' | xargs kill -9
   ```
2. **** (92% success)
   ```
   uvicorn app:app --port 8001
   ```

## Dead Ends

- **** — The old process keeps the port bound. (85% fail)
- **** — Reload does not free the port; the parent still binds it. (90% fail)