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.

Bericht für tarnkappe.info:80

Info Ping HTTP TCP UDP MTR DNS

TCP prüfen tarnkappe.info:80

Geprüft am Oct 23, 2026 09:17:19 UTC |

| Erneut prüfen |

Standort	Ergebnis	Zeit	IP-Adresse
Australia, Sydney	Connected	1.0 ms	34.120.87.59
Bosnia and Herzegovina, Novi Travnik	Connected	37.0 ms	34.120.87.59
Bulgaria, Sofia	Connected	22.0 ms	34.120.87.59
Canada, Montreal	Connected	1.0 ms	34.120.87.59
Switzerland, Bern	Connected	6.0 ms	34.120.87.59
Switzerland, Zurich	Connected	28.0 ms	34.120.87.59
China, Hohhot	Connected	151.0 ms	34.120.87.59
Cyprus, Larnaca	Connected	9.0 ms	34.120.87.59
Germany, Nuernberg	Connected	5.0 ms	34.120.87.59
Germany, Frankfurt am Main	Connected	1.0 ms	34.120.87.59
Germany, Frankfurt am Main	Connected	1.0 ms	34.120.87.59
Germany, Frankfurt am Main	Connected	1.0 ms	34.120.87.59
Germany, Koblenz	Connected	19.0 ms	34.120.87.59
Germany, Frankfurt am Main	Connected	5.0 ms	34.120.87.59
Denmark, Glostrup Municipality	Connected	29.0 ms	34.120.87.59
Spain, Bilbao	Connected	43.0 ms	34.120.87.59
Spain, Barcelona	Connected	22.0 ms	34.120.87.59
Finland, Helsinki	Connected	7.0 ms	34.120.87.59
Finland, Helsinki	Connected	12.0 ms	34.120.87.59
France, Gravelines	Connected	5.0 ms	34.120.87.59
France, Paris	Connected	15.0 ms	34.120.87.59
United Kingdom, London	Connected	8.0 ms	34.120.87.59
Hong Kong, Hong Kong	Connected	5.0 ms	34.120.87.59
Croatia, Zagreb	Connected	24.0 ms	34.120.87.59
Hungary, Budapest	Connected	29.0 ms	34.120.87.59
Israel, Petach Tikwa	Connected	2.0 ms	34.120.87.59
Israel, Netanja	Connected	3.0 ms	34.120.87.59
Iran, Tehran	Connected	83.0 ms	34.120.87.59
Iran, Tehran	Connected	83.0 ms	34.120.87.59
Iceland, Reykjavik (Miðborg)	Connected	23.0 ms	34.120.87.59
Italy, Como	Connected	2.0 ms	34.120.87.59
Japan, Tokyo	Connected	1.0 ms	34.120.87.59
South Korea, Seoul	Connected	37.0 ms	34.120.87.59
Kazakhstan, Almaty	Connected	91.0 ms	34.120.87.59
Lithuania, Pilaite	Connected	38.0 ms	34.120.87.59
Latvia, Riga	Connected	74.0 ms	34.120.87.59
Netherlands, Amsterdam	Connected	5.0 ms	34.120.87.59
Netherlands, Amsterdam	Connected	7.0 ms	34.120.87.59
Netherlands, Amsterdam	Connected	5.0 ms	34.120.87.59
Netherlands, Amsterdam	Connected	5.0 ms	34.120.87.59
Netherlands, Eygelshoven	Connected	8.0 ms	34.120.87.59
Norway, Oslo	Connected	12.0 ms	34.120.87.59
Poland, Warsaw	Connected	17.0 ms	34.120.87.59
Romania, Bacău	Connected	38.0 ms	34.120.87.59
Romania, Bucharest	Connected	32.0 ms	34.120.87.59
Serbia, Belgrade	Connected	31.0 ms	34.120.87.59
Russia, Moscow	Connected	27.0 ms	34.120.87.59
Singapore, Singapore	Connected	4.0 ms	34.120.87.59
Tor, Onion	Connected	336.0 ms	tarnkappe.info
Tor, Onion	Connected	46.0 ms	tarnkappe.info
Tor, Onion	Connected	68.0 ms	tarnkappe.info
Turkey, Istanbul	Connected	31.0 ms	34.120.87.59
Ukraine, Khmelnytskyi	Connected	38.0 ms	34.120.87.59
United States, Dallas	Connected	1.0 ms	34.120.87.59
United States, Los Angeles	Connected	35.0 ms	34.120.87.59
United States, Houston	Connected	7.0 ms	34.120.87.59
United States, Miami	Connected	28.0 ms	34.120.87.59
South Africa, Johannesburg	Connected	2.0 ms	34.120.87.59