# ConnectionRefusedError: [Errno 111] Connection refused

**Code:** `ConnectionRefusedError` · **Category:** Python · **Seen on:** Python

Nothing is listening on the host/port Python tried to connect to.

## Meaning

The target service (database, Redis, API) is down, on another port, or — in Docker — you’re connecting to localhost inside a container.

## Common causes

- Target service not running
- Wrong port
- localhost inside Docker
- Service listening only on 127.0.0.1 while connecting remotely

## Quick fix

1. Start the service and check its port
2. Use the compose service name as host
3. Bind the service to 0.0.0.0 when accessed remotely

## Detailed fix by platform

### Python

1. Retry with backoff on startup while dependencies come up

## How to diagnose

1. **Target** — host:port in the traceback
2. **Service** — Running?

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Source: [WhatIsMyError](https://whatismyerror.com/errors/python/connectionrefusederror)