Open port checker
Find out whether a port on your IP address is reachable from the internet. Handy after setting up port forwarding on your router.
- TCP, 3 s timeout
- your own IP only
- free, no ads
- CGNAT: if your router's WAN address differs from the address above, you share a public IPv4 with other customers of your ISP and port forwarding will not help. Ask your ISP for a public IPv4.
- The site runs through Cloudflare, but we test your real address that Cloudflare passes on to us. With a VPN, proxy or Cloudflare WARP that is the VPN's address, not your home one – turn them off for the test.
- We only test TCP. Games that use UDP only (Rust 28015, Minecraft Bedrock 19132) cannot be fully verified this way.
- Only your own address can be checked, never someone else's. The limit is 20 checks per 10 minutes.
How to check an open port
Start your server (Minecraft, FiveM, SSH…) and make sure it listens on all interfaces.
On your router, forward the port to the local IP of the server computer and allow it in the firewall.
Enter the port number or click a shortcut and run the check.
An open port means you are done; for closed or filtered, follow the suggested steps below the result.
About this tool
The StormHost open port checker tests whether a port on your public IP address can be reached from the internet. Our server in Prague tries a TCP connection and within 3 seconds tells you whether the port is open, closed or filtered by a firewall.
It is handy after setting up port forwarding for a Minecraft server, FiveM, Rust or remote desktop when friends cannot connect. Only the address you open the page from can be checked, so the tool cannot be misused to scan other people's networks.
- Connects from
- StormHost · TTC Teleport, Prague
- Target
- your own IP only
- Test
- TCP connect · 3 s timeout
- Limit
- 20 checks / 10 min
Frequently asked questions
Answers to the questions people ask most about this tool.
How do I check if a port is open?
Enter the port number (e.g. 25565 for Minecraft) or click a shortcut. Our server tries to connect to your public IP address and shows whether the port is open, closed or filtered.
What is the difference between a closed and a filtered port?
A closed port refuses the connection right away: the address is reachable but nothing listens on the port. A filtered port does not answer at all: a firewall dropped the connection or the router has no forwarding rule.
My port is forwarded but still closed. Why?
Usually the server is not running, listens only on 127.0.0.1, is blocked by the computer's firewall, or your provider uses CGNAT and shares a public IPv4 with other customers. Then router port forwarding does not help.
Can I check a port on another IP address?
No. The tool only tests the address your request came from. Checking other addresses would allow scanning networks without their owners' consent.
Does the test check UDP ports?
No, we test TCP. Games that use UDP only (such as Rust's game port or Minecraft Bedrock) cannot be fully verified with this test.
Related
- Firewall inside the VPS: UFW (and nftables for advanced users)Set up the UFW firewall right inside your VPS without locking yourself out: default policy, rules for services, limiting by IP address, limit, IPv6, logs. Why Docker bypasses UFW and how to use nftables.
- Minecraft server address: our subdomain or your own domainLet players join with a clean address and no port: a subdomain from us in a minute, or your own domain with A and SRV records. Steps for Cloudflare and other DNS, checks and fixes.
- Common Minecraft server errors and how to fix themExact Minecraft server and client error messages, what causes them and how to fix them: EULA, FAILED TO BIND TO PORT, UnsupportedClassVersionError, Incompatible client, Can't keep up, plugins, mods and more.
Want your own Minecraft server? Minecraft server hosting