Free Port Checker
Check if a TCP port is open on any host in seconds — open, closed, or filtered, with the service and connection time. No telnet, netcat, or nmap required.
Free · no sign-up · opens a live TCP connection from our servers.
What you get
What this port checker tells you
Enter a host and a port and Uptura opens a real TCP connection, then reports exactly what it found.
Open, closed, or filtered
A clear verdict on the port: open means something is listening and accepting connections; closed means the host is reachable but nothing is on that port; filtered means a firewall is silently dropping the connection.
The service on the port
For well-known ports we name the service that normally runs there — 443 is HTTPS, 22 is SSH, 3306 is MySQL, 5432 is PostgreSQL — so you can confirm the right thing is (or isn't) exposed.
Connection time
How many milliseconds the TCP connection took to establish, measured from our servers, so an open port that's slow to accept connections stands out.
Why it matters
Why check whether a port is open
A port check tells you what the outside world can actually reach on your server — the service you want up, or the one you meant to keep private.
Confirm a service is actually reachable
A service can be running on the server yet unreachable from the outside because a firewall, security group, or port-forwarding rule is blocking it. Checking the port from our end tells you what the rest of the internet actually sees.
Catch a port that shouldn't be open
An exposed database or admin port (3306, 5432, 6379, 3389) is a serious risk. A quick check tells you whether a port you meant to keep private is answering the public internet.
A check is a snapshot
This tells you the port's status this second. Whether your site is still answering on 443 at 3am on a Sunday is a different question — that's what continuous monitoring is for.
From checker to monitor
Know the moment your site stops responding
A port check is a snapshot. Uptura runs a real request against your site on 80/443 around the clock — and watches its SSL and DNS too — so you hear about an outage the instant it happens.
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Add your site
Point Uptura at the sites and endpoints that need to stay reachable. Free during our public beta — no credit card.
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We check that they answer, around the clock
Uptura connects to your site on 80/443 on a schedule — a real request, not just a ping — and watches its SSL certificate and DNS records at the same time.
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You get alerted the moment it stops responding
The instant your site stops answering — confirmed across consecutive checks to avoid false alarms — we notify you over email, Slack, or Discord, and again when it recovers.
Free during our public beta, no credit card required. Prefer to read more first? See how uptime monitoring works.
FAQ
Port checks, answered
How do I check if a port is open?
Enter a host (like example.com or an IP address) and a port number above, then run the check. Uptura opens a real TCP connection to that host and port from our servers and reports the result: open means a service accepted the connection, closed means the host answered but nothing is listening on that port, and filtered means there was no response at all — usually a firewall silently dropping the connection.
What's the difference between open, closed, and filtered?
Open means the connection was accepted — a service is listening and reachable. Closed means the host actively refused the connection (it sent a reset), so the machine is up but nothing is running on that port. Filtered means we got no answer before the timeout, which almost always means a firewall or security group is dropping the packets, so we can't tell whether the port is open or closed behind it.
How do I ping a specific port?
Ping itself uses ICMP and doesn't have a port, so "pinging a port" really means checking whether a TCP connection to that port succeeds. That's exactly what this tool does: give it a host and a port number and it attempts a TCP connection and tells you whether the port responds, without you needing telnet, netcat, or nmap installed.
What are the most common ports to check?
Web servers listen on 80 (HTTP) and 443 (HTTPS); SSH is 22; email uses 25, 465, 587, 993, and 995; and databases commonly use 3306 (MySQL), 5432 (PostgreSQL), 6379 (Redis), and 27017 (MongoDB). Remote desktop (RDP) is 3389. It's worth confirming your database and admin ports are NOT open to the public internet.
Why does a port show as filtered?
Filtered means our connection attempt got no response at all before timing out. That's the signature of a firewall, cloud security group, or router rule silently dropping the traffic rather than refusing it. If you expected the port to be open, check that the firewall or security-group rule allows inbound connections on that port from the public internet.
Is this port checker free?
Yes — the port checker is completely free and needs no sign-up. Check as many hosts and ports as you like. If you want to know the moment your site stops responding rather than checking by hand, you can set up free uptime, SSL, and DNS monitoring during our public beta and get alerted automatically.
Never be the last to know your site is down
Add your sites and let Uptura watch them around the clock — free during our public beta, no credit card required.
Free during beta · no credit card required