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.

تقرير لـ telecom-nl.com:80

Info Ping HTTP TCP UDP MTR DNS

فحص TCP telecom-nl.com:80

تم الفحص في Jun 8, 2026 03:38:15 (UTC) |

| افحص تاني |

المكان (Location)	النتيجة	الوقت	عنوان الـ IP
Albania, Tirana	Connected	71.0 ms	77.111.243.33
Australia, Sydney	Connected	279.0 ms	77.111.243.33
Bosnia and Herzegovina, Novi Travnik	Connected	41.0 ms	77.111.243.33
Bulgaria, Sofia	Connected	40.0 ms	77.111.243.33
Canada, Montreal	Connected	105.0 ms	77.111.243.33
Switzerland, Bern	Connected	20.0 ms	77.111.243.33
Switzerland, Zurich	Connected	27.0 ms	77.111.243.33
Chile, Santiago	Connected	210.0 ms	77.111.243.33
China, Hohhot	Connected	279.0 ms	77.111.243.33
Germany, Nuernberg	Connected	20.0 ms	77.111.243.33
Germany, Frankfurt am Main	Connected	15.0 ms	77.111.243.33
Germany, Frankfurt am Main	Connected	13.0 ms	77.111.243.33
Germany, Frankfurt am Main	Connected	13.0 ms	77.111.243.33
Germany, Duesseldorf	Connected	15.0 ms	77.111.243.33
Germany, Frankfurt am Main	Connected	15.0 ms	77.111.243.33
Denmark, Glostrup Municipality	Connected	30.0 ms	77.111.243.33
Spain, Bilbao	Connected	61.0 ms	77.111.243.33
Spain, Barcelona	Connected	37.0 ms	77.111.243.33
Finland, Helsinki	ERROR	-	77.111.243.33
Finland, Helsinki	Connected	40.0 ms	77.111.243.33
France, Gravelines	Connected	22.0 ms	77.111.243.33
France, Paris	Connected	39.0 ms	77.111.243.33
United Kingdom, London	Connected	27.0 ms	77.111.243.33
Georgia, Tbilisi	Connected	300.0 ms	telecom-nl.com
Hong Kong, Hong Kong	Connected	23.0 ms	77.111.243.33
Croatia, Zagreb	Connected	29.0 ms	77.111.243.33
Hungary, Budapest	Connected	47.0 ms	77.111.243.33
Indonesia, Jakarta	Connected	250.0 ms	77.111.243.33
Israel, Petach Tikwa	Connected	67.0 ms	77.111.243.33
Israel, Netanja	Connected	71.0 ms	77.111.243.33
India, New Delhi	Connected	284.0 ms	77.111.243.33
Iceland, Reykjavik (Miðborg)	Connected	49.0 ms	77.111.243.33
Italy, Como	Connected	22.0 ms	77.111.243.33
Kazakhstan, Almaty	Connected	103.0 ms	77.111.243.33
Lithuania, Pilaite	Connected	58.0 ms	77.111.243.33
Latvia, Riga	Connected	57.0 ms	77.111.243.33
Moldova, Chisinau	Connected	96.0 ms	77.111.243.33
Netherlands, Amsterdam	Connected	13.0 ms	77.111.243.33
Netherlands, Amsterdam	Connected	14.0 ms	77.111.243.33
Netherlands, Amsterdam	Connected	12.0 ms	77.111.243.33
Netherlands, Amsterdam	Connected	12.0 ms	77.111.243.33
Netherlands, Eygelshoven	Connected	15.0 ms	77.111.243.33
Norway, Oslo	Connected	7.0 ms	77.111.243.33
Poland, Warsaw	ERROR	-	77.111.243.33
Romania, Bacău	Connected	53.0 ms	77.111.243.33
Romania, Bucharest	Connected	43.0 ms	77.111.243.33
Serbia, Belgrade	Connected	48.0 ms	77.111.243.33
Russia, Moscow	Connected	29.0 ms	77.111.243.33
Saudi Arabia, Riyadh	Connected	95.0 ms	77.111.243.33
Tor, Onion	Connected	107.0 ms	telecom-nl.com
Tor, Onion	Connected	119.0 ms	telecom-nl.com
Tor, Onion	Connected	150.0 ms	telecom-nl.com
Turkey, Istanbul	Connected	48.0 ms	77.111.243.33
Turkey, Istanbul	Connected	50.0 ms	77.111.243.33
Taiwan, Taipei	Connected	233.0 ms	77.111.243.33
Ukraine, Khmelnytskyi	Connected	49.0 ms	77.111.243.33
United States, Dallas	Connected	119.0 ms	77.111.243.33
United States, Kansas City	Connected	116.0 ms	77.111.243.33
United States, Dallas	Connected	120.0 ms	77.111.243.33
United States, Los Angeles	Connected	138.0 ms	77.111.243.33
United States, Houston	Connected	143.0 ms	77.111.243.33
United States, Miami	Connected	140.0 ms	77.111.243.33
South Africa, Johannesburg	Connected	171.0 ms	77.111.243.33