How do I check if a TCP port is open online?

Enter your server's IP address or domain followed by a colon and the port number (e.g. 1.1.1.1:80 or example.com:443) and run a TCP check. The tool attempts a TCP handshake from 65+ global nodes and reports whether each connection succeeded, was refused, or timed out.

What is the difference between a port being refused versus timing out?

A refused connection (TCP RST) means the port is actively closed — the server replied to reject the connection. A timeout means no reply was received at all, which typically indicates a firewall is silently dropping packets before they reach the server or application.

Which TCP ports can I test?

Any valid TCP port from 1 to 65535. Common examples include port 80 (HTTP), 443 (HTTPS), 22 (SSH), 25 (SMTP), 3306 (MySQL), 5432 (PostgreSQL), and 3389 (RDP). No login or special permissions required — the check only verifies whether the TCP handshake completes.

My port is open locally but fails from external nodes — why?

If a port works locally but fails from external nodes, something between the internet and your server is blocking it — commonly a cloud security group, iptables rule, upstream ISP filter, or geoblocking policy. Running the check from multiple regions helps identify whether the block is global or specific to certain countries or ASNs.

Report for 1.1.1.1:80

Info Ping HTTP TCP UDP MTR DNS

Check TCP 1.1.1.1:80

Checked Oct 23, 2026 19:25:57 UTC |

| Check again |

ठिकाण	निकाल	वेळ	IP Address
Albania, Tirana	Connected	99.0 ms	1.1.1.1
Australia, Sydney	Connected	1.0 ms	1.1.1.1
Bosnia and Herzegovina, Novi Travnik	Connected	17.0 ms	1.1.1.1
Bulgaria, Sofia	Connected	31.0 ms	1.1.1.1
Canada, Montreal	Connected	8.0 ms	1.1.1.1
Switzerland, Bern	Connected	1.0 ms	1.1.1.1
Switzerland, Zurich	Connected	44.0 ms	1.1.1.1
China, Hohhot	Connected	203.0 ms	1.1.1.1
Cyprus, Larnaca	Connected	5.0 ms	1.1.1.1
Germany, Nuernberg	Connected	14.0 ms	1.1.1.1
Germany, Frankfurt am Main	Connected	2.0 ms	1.1.1.1
Germany, Frankfurt am Main	Connected	0.0 ms	1.1.1.1
Germany, Frankfurt am Main	Connected	1.0 ms	1.1.1.1
Germany, Koblenz	Connected	26.0 ms	1.1.1.1
Germany, Frankfurt am Main	Connected	5.0 ms	1.1.1.1
Denmark, Glostrup Municipality	Connected	33.0 ms	1.1.1.1
Spain, Bilbao	Connected	42.0 ms	1.1.1.1
Spain, Barcelona	Connected	19.0 ms	1.1.1.1
Finland, Helsinki	Connected	6.0 ms	1.1.1.1
Finland, Helsinki	Connected	19.0 ms	1.1.1.1
France, Gravelines	Connected	5.0 ms	1.1.1.1
France, Paris	Connected	239.0 ms	1.1.1.1
United Kingdom, London	Connected	8.0 ms	1.1.1.1
Hong Kong, Hong Kong	Connected	7.0 ms	1.1.1.1
Croatia, Zagreb	Connected	28.0 ms	1.1.1.1
Hungary, Budapest	Connected	45.0 ms	1.1.1.1
Israel, Petach Tikwa	Connected	1.0 ms	1.1.1.1
Israel, Netanja	Connected	1.0 ms	1.1.1.1
Iran, Tehran	Connected	133.0 ms	1.1.1.1
Iran, Tehran	Connected	109.0 ms	1.1.1.1
Iceland, Reykjavik (Miðborg)	Connected	6.0 ms	1.1.1.1
Italy, Como	Connected	1.0 ms	1.1.1.1
Japan, Tokyo	Connected	1.0 ms	1.1.1.1
South Korea, Seoul	Connected	2.0 ms	1.1.1.1
Kazakhstan, Almaty	Connected	2.0 ms	1.1.1.1
Lithuania, Pilaite	Connected	66.0 ms	1.1.1.1
Latvia, Riga	Connected	75.0 ms	1.1.1.1
Moldova, Chisinau	Connected	106.0 ms	1.1.1.1
Netherlands, Amsterdam	Connected	2.0 ms	1.1.1.1
Netherlands, Amsterdam	Connected	3.0 ms	1.1.1.1
Netherlands, Amsterdam	Connected	3.0 ms	1.1.1.1
Netherlands, Amsterdam	Connected	3.0 ms	1.1.1.1
Netherlands, Eygelshoven	Connected	178.0 ms	1.1.1.1
Norway, Oslo	Connected	0.0 ms	1.1.1.1
Poland, Warsaw	Connected	17.0 ms	1.1.1.1
Romania, Bacău	Connected	53.0 ms	1.1.1.1
Romania, Bucharest	Connected	9.0 ms	1.1.1.1
Serbia, Belgrade	Connected	7.0 ms	1.1.1.1
Russia, Moscow	Connected	21.0 ms	1.1.1.1
Singapore, Singapore	Connected	3.0 ms	1.1.1.1
Tor, Onion	Connected	901.0 ms	1.1.1.1
Tor, Onion	Connected	730.0 ms	1.1.1.1
Tor, Onion	Connected	857.0 ms	1.1.1.1
Turkey, Istanbul	Connected	9.0 ms	1.1.1.1
Ukraine, Khmelnytskyi	Connected	5.0 ms	1.1.1.1
United States, Dallas	Connected	1.0 ms	1.1.1.1
United States, Los Angeles	Connected	1.0 ms	1.1.1.1
United States, Houston	Connected	7.0 ms	1.1.1.1
United States, Miami	Connected	1.0 ms	1.1.1.1
South Africa, Johannesburg	Connected	2.0 ms	1.1.1.1