Help Centre
Getting started, common questions, known limitations, and how to reach us.
Getting started
Go to the app
Open the Portpeek app — no account, sign-up, or download needed.
Enter a hostname or IP
Type the domain name (e.g. example.com) or IP address of the server you want to test.
Select the ports you care about
Check the boxes for common service ports (80, 443, 22, 8080, 3306, 5432, 6379). Enter one custom port if you need a non-standard one.
Click "Check ports"
All selected ports are tested in parallel from outside your network. Results appear in seconds with the measured latency.
Frequently asked questions
What's the difference between "refused" and "timed out"?
This is Portpeek's core distinction, and it matters because the two causes have completely different fixes:
- Connection refused — The host answered your connection attempt with an RST (reset) packet. The server is reachable on the network, but nothing is listening on that port. Fix: check that your service is running, bound to the right interface (not just
127.0.0.1), and that no local firewall on the server itself is blocking it. - Timed out — No response at all. Something between you and the host is silently dropping the SYN packet — typically a network firewall, cloud security group rule, or NAT configuration. Fix: check your firewall rules, cloud provider security group, or router port forwarding.
- Connected — TCP handshake succeeded. The port is reachable from the internet and a service is responding.
Why can't I check port 25?
Port 25 (SMTP) is blocked on our check infrastructure. Outbound port 25 is prohibited by our hosting platform, and attempting a check would always fail misleadingly. We do not offer port 25 checks and cannot work around this restriction. If you need to verify port 25 reachability, you will need to use a different tool or a host that allows outbound SMTP traffic.
Do you store my hostnames, IPs, or results?
No. Portpeek does not store, log, or retain any data from your checks — not the hostname, not the IP address, not the selected ports, not the results. No cookies are used. The result you see on screen is the only record of the check. Once you navigate away or refresh, it's gone. There are no accounts, so there is nothing to associate a check with.
How long does a check take? What timeout do you use?
Checks are performed in parallel, so the total time is roughly the slowest single port attempt. By default, each port gets up to 5 seconds to connect. If a port is unreachable (firewall dropping traffic), it will take the full 5 seconds to time out. If a port connects or is refused, the result comes back in milliseconds. Most checks complete in under 6 seconds.
The timeout is currently fixed and cannot be changed — adjustable timeouts are planned for the Pro tier.
I opened a port in my firewall. Why is Portpeek still showing "refused"?
"Refused" means your server received the connection but nothing is listening on that port. This typically means:
- Your service is not running, or it crashed.
- Your service is listening only on
127.0.0.1(localhost) instead of0.0.0.0(all interfaces). Check your service config — many frameworks default to localhost-only. - A local firewall on the server itself (e.g.
iptables,ufw) is rejecting the connection at the host level rather than silently dropping it.
If you see "timed out" instead, that means no response arrived at all — the problem is somewhere between the internet and your server (cloud firewall, router, NAT).
Can I check multiple hostnames at the same time?
Not currently. Each check accepts a single hostname or IP address. You can run multiple checks back-to-back, but there is no batch or multi-host feature yet. This is planned for the Pro tier but not available today.
Is there an API or CLI tool?
Not yet. Portpeek is currently a web-only tool. An API with an API key is planned for the Pro tier. There is no CLI client, no cURL endpoint, and no way to automate checks programmatically at this time.
Do I need an account or to pay anything?
No. Portpeek is completely free, no account required, no sign-up, no payment. The Pro plan with additional features is planned but not yet available — the pricing page clearly marks all Pro features as "Planned" and the subscribe button as disabled.
Known limitations
Portpeek is a focused tool built to answer one question clearly. Here is what it does not do — and the things that are still being built:
Portpeek answers when you ask it — there is no notification system, no email sender, and no way to set up recurring checks. If a port goes down, you will not be told. This tool has no sender infrastructure and cannot promise otherwise.
You can only check ports you explicitly select. Portpeek does not scan ranges, enumerate open ports, or discover services. It is a reachability check, not a port scanner.
Outbound port 25 is prohibited by our hosting infrastructure. We cannot check SMTP ports. This is a hard platform limitation.
You can enter at most one custom port per check in addition to the seven predefined common ports. The predefined set is: 80, 443, 22, 3306, 5432, 6379, 8080.
API access, adjustable timeouts, multiple hostnames per check, priority support, and export results as JSON/CSV are planned for the Pro tier but are not available today. The checkout form on the pricing page is a demonstration — no real payment is taken, no account is created.
Check results live only in your browser until you navigate away. There is no history, no export, and no saved results feature. Take a screenshot if you need to keep a record.
Contact us
If a check returns incorrect or unexpected results, or the app itself fails, please describe exactly what you entered and what you saw. Include any error messages.
We read every request. Be specific — "more ports" or "faster checks" are harder to act on than "allow setting a custom timeout in seconds".
Check the Terms of Service for legal and usage policy questions. If your question isn't answered there or on this page, reach out with as much detail as possible.
Portpeek has no built-in contact form, no email system, and no ticketing platform. Support is handled directly by the service owner. Please include your question clearly — we can only help with what we can see.