Port 5683: CoAP
Port 5683 is CoAP, the Constrained Application Protocol designed for small, low-power IoT devices that cannot afford the overhead of full HTTP. It mirrors HTTP's request and response model but runs over UDP with a much lighter binary format.
| Port number | 5683 |
|---|---|
| Service | Constrained Application Protocol |
| Protocol | UDP |
| Category | IoT & automation |
| Default encryption | No |
Frequently asked questions
What is port 5683 used for?
Port 5683 is CoAP, the Constrained Application Protocol designed for small, low-power IoT devices that cannot afford the overhead of full HTTP. It mirrors HTTP's request and response model but runs over UDP with a much lighter binary format.
Is port 5683 TCP or UDP?
Port 5683 (CoAP) uses UDP.
Is port 5683 secure?
Port 5683 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.
Should I open port 5683 on my firewall?
Only if you specifically need CoAP. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.