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.

ideal.nl:80 için Rapor

Info Ping HTTP TCP UDP MTR DNS

TCP Kontrol ideal.nl:80

Jun 13, 2026 10:49:58 UTC tarihinde kontrol edildi |

| Tekrar kontrol et |

Konum	Sonuç	Süre	IP Adresi
Albania, Tirana	Connected	66.0 ms	3.127.1.83
Australia, Sydney	Connected	252.0 ms	3.127.1.83
Bosnia and Herzegovina, Novi Travnik	Connected	26.0 ms	3.127.1.83
Bulgaria, Sofia	Connected	27.0 ms	3.127.1.83
Canada, Montreal	Connected	90.0 ms	3.127.1.83
Switzerland, Bern	ERROR	-	3.127.1.83
Switzerland, Zurich	Connected	15.0 ms	3.127.1.83
Chile, Santiago	Connected	199.0 ms	3.127.1.83
China, Hohhot	Connected	210.0 ms	3.127.1.83
Germany, Nuernberg	Connected	5.0 ms	3.127.1.83
Germany, Frankfurt am Main	Connected	2.0 ms	3.127.1.83
Germany, Frankfurt am Main	Connected	2.0 ms	3.127.1.83
Germany, Limburg	Connected	3.0 ms	3.127.1.83
Germany, Frankfurt am Main	Connected	2.0 ms	3.127.1.83
Germany, Duesseldorf	Connected	6.0 ms	3.127.1.83
Germany, Frankfurt am Main	Connected	2.0 ms	3.127.1.83
Denmark, Glostrup Municipality	Connected	26.0 ms	3.127.1.83
Spain, Barcelona	Connected	27.0 ms	3.127.1.83
Finland, Helsinki	ERROR	-	3.127.1.83
Finland, Helsinki	Connected	51.0 ms	3.127.1.83
France, Gravelines	Connected	13.0 ms	3.127.1.83
France, Paris	Connected	18.0 ms	3.127.1.83
United Kingdom, London	Connected	18.0 ms	3.127.1.83
Georgia, Tbilisi	Connected	306.0 ms	ideal.nl
Croatia, Zagreb	Connected	27.0 ms	3.127.1.83
Hungary, Budapest	Connected	30.0 ms	3.127.1.83
Indonesia, Jakarta	Connected	241.0 ms	3.127.1.83
Israel, Petach Tikwa	Connected	59.0 ms	3.127.1.83
Israel, Netanja	Connected	59.0 ms	3.127.1.83
India, New Delhi	Connected	269.0 ms	3.127.1.83
Iceland, Reykjavik (Miðborg)	Connected	43.0 ms	3.127.1.83
Italy, Como	Connected	14.0 ms	3.127.1.83
Kazakhstan, Almaty	Connected	85.0 ms	3.127.1.83
Lithuania, Pilaite	Connected	56.0 ms	3.127.1.83
Latvia, Riga	Connected	66.0 ms	3.127.1.83
Moldova, Chisinau	Connected	77.0 ms	3.127.1.83
Netherlands, Amsterdam	Connected	7.0 ms	3.127.1.83
Netherlands, Amsterdam	Connected	25.0 ms	3.127.1.83
Netherlands, Amsterdam	Connected	8.0 ms	3.127.1.83
Netherlands, Amsterdam	Connected	8.0 ms	3.127.1.83
Netherlands, Eygelshoven	Connected	11.0 ms	3.127.1.83
Norway, Oslo	Connected	45.0 ms	3.127.1.83
Poland, Warsaw	Connected	42.0 ms	3.127.1.83
Romania, Bacău	Connected	40.0 ms	3.127.1.83
Romania, Bucharest	Connected	43.0 ms	3.127.1.83
Serbia, Belgrade	Connected	24.0 ms	3.127.1.83
Russia, Moscow	Connected	44.0 ms	3.127.1.83
Saudi Arabia, Riyadh	Connected	86.0 ms	3.127.1.83
Tor, Onion	Connected	120.0 ms	ideal.nl
Tor, Onion	Connected	51.0 ms	ideal.nl
Tor, Onion	Connected	129.0 ms	ideal.nl
Turkey, Istanbul	Connected	42.0 ms	3.127.1.83
Turkey, Istanbul	Connected	42.0 ms	3.127.1.83
Taiwan, Taipei	Connected	288.0 ms	3.127.1.83
Ukraine, Khmelnytskyi	Connected	37.0 ms	3.127.1.83
United States, Dallas	Connected	122.0 ms	3.127.1.83
United States, Kansas City	Connected	156.0 ms	3.127.1.83
United States, Dallas	Connected	122.0 ms	3.127.1.83
United States, Los Angeles	Connected	153.0 ms	3.127.1.83
United States, Houston	Connected	136.0 ms	3.127.1.83
United States, Miami	Connected	130.0 ms	3.127.1.83
South Africa, Johannesburg	Connected	243.0 ms	3.127.1.83