localhost:4566: what runs on it and how to open it
Port 4566 is the LocalStack gateway for local AWS services. How to start it and test it.
Open this address: http://localhost:4566This opens on your own computer. It only works if the program is running.
localhost:4566 is the single address LocalStack uses for the AWS services it imitates. Point your AWS tools at it with the endpoint option.
What runs on localhost:4566
- LocalStack, a local copy of AWS services
Commands to start and test port 4566
docker run -d -p 4566:4566 localstack/localstackcurl http://localhost:4566/_localstack/healthaws --endpoint-url=http://localhost:4566 s3 lsFind what is using port 4566
Run these in a terminal on your computer. Nothing is sent to this site.
If localhost:4566 will not open
- The AWS CLI asks for credentials
- LocalStack accepts any values. Set dummy ones, for example AWS_ACCESS_KEY_ID=test and AWS_SECRET_ACCESS_KEY=test.
- Port 4566 is already in use
- Another program is on this port. Find it with the tool below and stop it, or start yours on another port.
- This site can’t be reached (ERR_CONNECTION_REFUSED)
- The program is not running. Start it and keep that terminal open. See the full checklist.
- Works on your computer, not on your phone
- Start the server on all network addresses and use your computer’s IP address. See how to open localhost from your phone.
Other ports like 4566
| Port | Usually used by |
|---|---|
| localhost:11434 | Ollama (AI models) |
| localhost:5601 | Kibana |
| localhost:11501 | Not a standard port: check what is using it |
| localhost:9200 | Elasticsearch |
| localhost:5672 | RabbitMQ |
| localhost:15672 | RabbitMQ admin page |
| localhost:9090 | Prometheus |
Questions about localhost:4566
- Does it use real AWS?
- No. It runs on your computer and does not create real AWS resources.
- Is localhost:4566 safe?
- Yes, as long as it stays on localhost. Only your own computer can reach it. It becomes reachable from other devices only if you start the program on 0.0.0.0 or your computer's IP address. Do not put development or admin tools on the public internet.
- Can I use a different port instead of 4566?
- Yes. Most programs let you choose the port with a setting or a command option. Pick a free port above 1024 and open that number instead.
- How do I check what is using port 4566?
- Use the port checker on this page. It shows the command for Windows, macOS and Linux and does not send anything to this site.
- Can I open localhost:4566 from my phone?
- Yes, if both are on the same Wi-Fi. Start the program so it listens on all addresses, then open your computer's IP address with the port on the phone. A firewall on the computer can still block it.
Free tools that help
- Common ports listSearch a list of common TCP and UDP port numbers: SSH 22, HTTP 80, HTTPS 443, MySQL 3306, PostgreSQL 5432 and more, with dev server ports.