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 50+ 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 google.com:80

Info Ping HTTP TCP UDP MTR DNS

Check TCP google.com:80

Checked Apr 21, 2026 12:16:14 UTC |

| Check again |

ठिकाण	निकाल	वेळ	IP Address
Albania, Tirana	Connected	107.0 ms	172.217.22.238
Australia, Sydney	Connected	0.0 ms	142.251.222.238
Bosnia and Herzegovina, Novi Travnik	Connected	48.0 ms	142.251.140.78
Bulgaria, Sofia	Connected	1.0 ms	192.178.25.238
Canada, Montreal	Connected	2.0 ms	64.233.178.102
Switzerland, Bern	Connected	2.0 ms	74.125.29.138
Chile, Santiago	Connected	1.0 ms	142.251.0.100
China, Hohhot	ERROR	-	142.250.73.110
Germany, Nuernberg	Connected	4.0 ms	142.250.154.113
Germany, Frankfurt am Main	Connected	1.0 ms	142.251.20.113
Germany, Frankfurt am Main	Connected	1.0 ms	142.251.20.100
Germany, Limburg	Connected	2.0 ms	142.251.110.100
Germany, Frankfurt am Main	Connected	0.0 ms	142.250.186.78
Germany, Duesseldorf	Connected	4.0 ms	172.217.23.238
Denmark, Glostrup Municipality	Connected	25.0 ms	192.178.25.14
Spain, Bilbao	Connected	37.0 ms	142.251.13.113
Finland, Helsinki	Connected	19.0 ms	142.251.38.78
Finland, Helsinki	Connected	16.0 ms	142.251.38.78
France, Gravelines	Connected	11.0 ms	142.251.14.138
France, Paris	Connected	9.0 ms	142.251.39.110
United Kingdom, London	Connected	6.0 ms	142.251.29.113
Georgia, Tbilisi	ERROR	-	google.com
Greece, Athens	ERROR	-	google.com
Hong Kong, Hong Kong	Connected	3.0 ms	216.58.198.14
Croatia, Zagreb	Connected	36.0 ms	142.251.20.100
Hungary, Budapest	ERROR	-	-
Indonesia, Jakarta	Connected	1.0 ms	142.251.12.139
Israel, Petach Tikwa	Connected	1.0 ms	142.250.75.110
Israel, Netanja	Connected	3.0 ms	142.250.75.206
India, New Delhi	Connected	1.0 ms	172.217.24.78
Iceland, Reykjavik (Miðborg)	Connected	36.0 ms	142.250.180.14
Italy, Como	Connected	32.0 ms	192.178.204.100
Kuwait, Kuwait City	ERROR	-	google.com
Lithuania, Pilaite	Connected	77.0 ms	172.217.19.238
Latvia, Riga	Connected	99.0 ms	142.250.102.100
Moldova, Chisinau	Connected	119.0 ms	192.178.24.174
Netherlands, Amsterdam	Connected	1.0 ms	142.251.142.206
Netherlands, Amsterdam	Connected	3.0 ms	172.217.23.238
Netherlands, Amsterdam	Connected	1.0 ms	172.217.23.238
Netherlands, Amsterdam	Connected	1.0 ms	172.217.23.238
Norway, Oslo	Connected	33.0 ms	209.85.203.138
Poland, Warsaw	Connected	15.0 ms	142.251.98.113
Romania, Bacău	Connected	34.0 ms	142.250.201.78
Romania, Bucharest	Connected	10.0 ms	192.178.24.14
Serbia, Belgrade	Connected	121.0 ms	142.251.20.138
Russia, St Petersburg	Connected	5.0 ms	108.177.14.138
Singapore, Singapore	Connected	1.0 ms	142.250.4.139
Turkey, Istanbul	Connected	12.0 ms	172.217.21.238
Taiwan, Taipei	Connected	1.0 ms	142.250.198.78
United States, Miami	Connected	60.0 ms	142.251.215.46
United States, Dallas	Connected	18.0 ms	142.251.116.102
United States, Kansas City	Connected	37.0 ms	172.217.214.138
United States, Dallas	Connected	2.0 ms	142.251.116.102
South Africa, Johannesburg	Connected	0.0 ms	142.251.47.142