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.

Relatório para cloudflare.com:80

Info Ping HTTP TCP UDP MTR DNS

Verificar TCP cloudflare.com:80

Verificado em Oct 23, 2026 12:29:17 UTC |

| Verificar novamente |

Local	Resultado	Tempo	Endereço IP
Albania, Tirana	Connected	114.0 ms	104.16.132.229
Australia, Sydney	Connected	1.0 ms	104.16.133.229
Bosnia and Herzegovina, Novi Travnik	Connected	17.0 ms	104.16.132.229
Bulgaria, Sofia	Connected	1.0 ms	104.16.133.229
Canada, Montreal	Connected	8.0 ms	104.16.133.229
Switzerland, Bern	Connected	1.0 ms	104.16.132.229
Switzerland, Zurich	Connected	26.0 ms	104.16.132.229
China, Hohhot	Connected	279.0 ms	104.16.133.229
Cyprus, Larnaca	Connected	2.0 ms	104.16.133.229
Germany, Nuernberg	Connected	14.0 ms	104.16.133.229
Germany, Frankfurt am Main	Connected	1.0 ms	104.16.132.229
Germany, Frankfurt am Main	Connected	1.0 ms	104.16.133.229
Germany, Frankfurt am Main	Connected	2.0 ms	104.16.133.229
Germany, Koblenz	Connected	23.0 ms	104.16.132.229
Germany, Frankfurt am Main	Connected	5.0 ms	104.16.132.229
Denmark, Glostrup Municipality	Connected	58.0 ms	104.16.133.229
Spain, Bilbao	Connected	60.0 ms	104.16.132.229
Spain, Barcelona	Connected	18.0 ms	104.16.133.229
Finland, Helsinki	Connected	6.0 ms	104.16.133.229
Finland, Helsinki	Connected	20.0 ms	104.16.132.229
France, Gravelines	Connected	5.0 ms	104.16.133.229
France, Paris	Connected	64.0 ms	104.16.133.229
United Kingdom, London	Connected	9.0 ms	104.16.132.229
Hong Kong, Hong Kong	Connected	7.0 ms	104.16.132.229
Croatia, Zagreb	Connected	44.0 ms	104.16.132.229
Hungary, Budapest	Connected	67.0 ms	104.16.133.229
Israel, Petach Tikwa	Connected	1.0 ms	104.16.133.229
Israel, Netanja	Connected	1.0 ms	104.16.132.229
Iran, Tehran	Connected	84.0 ms	104.16.132.229
Iran, Tehran	Connected	86.0 ms	104.16.133.229
Iceland, Reykjavik (Miðborg)	Connected	2.0 ms	104.16.132.229
Italy, Como	Connected	1.0 ms	104.16.133.229
Japan, Tokyo	Connected	1.0 ms	104.16.132.229
South Korea, Seoul	Connected	2.0 ms	104.16.132.229
Kazakhstan, Almaty	Connected	1.0 ms	104.16.132.229
Lithuania, Pilaite	Connected	97.0 ms	104.16.133.229
Latvia, Riga	Connected	107.0 ms	104.16.132.229
Moldova, Chisinau	Connected	132.0 ms	104.16.133.229
Netherlands, Amsterdam	Connected	2.0 ms	104.16.132.229
Netherlands, Amsterdam	Connected	3.0 ms	104.16.132.229
Netherlands, Amsterdam	Connected	1.0 ms	104.16.132.229
Netherlands, Amsterdam	Connected	1.0 ms	104.16.133.229
Netherlands, Eygelshoven	Connected	4.0 ms	104.16.132.229
Norway, Oslo	Connected	0.0 ms	104.16.132.229
Poland, Warsaw	Connected	16.0 ms	104.16.132.229
Romania, Bacău	Connected	38.0 ms	104.16.132.229
Romania, Bucharest	Connected	8.0 ms	104.16.133.229
Serbia, Belgrade	Connected	7.0 ms	104.16.132.229
Russia, Moscow	Connected	24.0 ms	104.16.132.229
Singapore, Singapore	Connected	2.0 ms	104.16.133.229
Turkey, Istanbul	Connected	9.0 ms	104.16.133.229
Ukraine, Khmelnytskyi	Connected	5.0 ms	104.16.133.229
United States, Dallas	Connected	1.0 ms	104.16.132.229
United States, Los Angeles	Connected	2.0 ms	104.16.133.229
United States, Houston	Connected	7.0 ms	104.16.132.229
United States, Miami	Connected	1.0 ms	104.16.133.229
South Africa, Johannesburg	Connected	2.0 ms	104.16.133.229