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.

Report for 1.1.1.1:80

Location	Result	Time	IP Address
Albania, Tirana	Connected	223.0 ms	1.1.1.1
Australia, Sydney	Connected	1.0 ms	1.1.1.1
Bosnia and Herzegovina, Novi Travnik	Connected	18.0 ms	1.1.1.1
Bulgaria, Sofia	Connected	32.0 ms	1.1.1.1
Canada, Montreal	Connected	11.0 ms	1.1.1.1
Switzerland, Bern	Connected	1.0 ms	1.1.1.1
Switzerland, Zurich	Connected	19.0 ms	1.1.1.1
China, Hohhot	Connected	336.0 ms	1.1.1.1
Cyprus, Larnaca	Connected	2.0 ms	1.1.1.1
Germany, Nuernberg	Connected	15.0 ms	1.1.1.1
Germany, Frankfurt am Main	Connected	0.0 ms	1.1.1.1
Germany, Frankfurt am Main	Connected	1.0 ms	1.1.1.1
Germany, Frankfurt am Main	Connected	2.0 ms	1.1.1.1
Germany, Koblenz	Connected	20.0 ms	1.1.1.1
Germany, Frankfurt am Main	Connected	5.0 ms	1.1.1.1
Denmark, Glostrup Municipality	Connected	25.0 ms	1.1.1.1
Spain, Bilbao	Connected	42.0 ms	1.1.1.1
Spain, Barcelona	Connected	18.0 ms	1.1.1.1
Finland, Helsinki	Connected	5.0 ms	1.1.1.1
Finland, Helsinki	Connected	19.0 ms	1.1.1.1
France, Gravelines	Connected	5.0 ms	1.1.1.1
France, Paris	Connected	10.0 ms	1.1.1.1
United Kingdom, London	Connected	8.0 ms	1.1.1.1
Hong Kong, Hong Kong	Connected	6.0 ms	1.1.1.1
Croatia, Zagreb	Connected	30.0 ms	1.1.1.1
Hungary, Budapest	Connected	14.0 ms	1.1.1.1
Israel, Petach Tikwa	Connected	1.0 ms	1.1.1.1
Israel, Netanja	Connected	1.0 ms	1.1.1.1
Iran, Tehran	Connected	1.0 ms	1.1.1.1
Iran, Tehran	Connected	1.0 ms	1.1.1.1
Iceland, Reykjavik (Miðborg)	Connected	2.0 ms	1.1.1.1
Italy, Como	Connected	1.0 ms	1.1.1.1
Japan, Tokyo	Connected	1.0 ms	1.1.1.1
South Korea, Seoul	Connected	2.0 ms	1.1.1.1
Kazakhstan, Almaty	Connected	2.0 ms	1.1.1.1
Lithuania, Pilaite	Connected	73.0 ms	1.1.1.1
Latvia, Riga	Connected	31.0 ms	1.1.1.1
Moldova, Chisinau	Connected	70.0 ms	1.1.1.1
Netherlands, Amsterdam	Connected	1.0 ms	1.1.1.1
Netherlands, Amsterdam	Connected	3.0 ms	1.1.1.1
Netherlands, Amsterdam	Connected	1.0 ms	1.1.1.1
Netherlands, Amsterdam	Connected	1.0 ms	1.1.1.1
Netherlands, Eygelshoven	Connected	4.0 ms	1.1.1.1
Norway, Oslo	Connected	1.0 ms	1.1.1.1
Poland, Warsaw	Connected	16.0 ms	1.1.1.1
Romania, Bacău	Connected	53.0 ms	1.1.1.1
Romania, Bucharest	Connected	8.0 ms	1.1.1.1
Serbia, Belgrade	Connected	7.0 ms	1.1.1.1
Russia, Moscow	Connected	25.0 ms	1.1.1.1
Singapore, Singapore	Connected	2.0 ms	1.1.1.1
Tor, Onion	ERROR	-	1.1.1.1
Tor, Onion	ERROR	-	1.1.1.1
Tor, Onion	ERROR	-	1.1.1.1
Turkey, Istanbul	Connected	9.0 ms	1.1.1.1
Ukraine, Khmelnytskyi	Connected	6.0 ms	1.1.1.1
United States, Dallas	Connected	2.0 ms	1.1.1.1
United States, Los Angeles	Connected	1.0 ms	1.1.1.1
United States, Houston	Connected	7.0 ms	1.1.1.1
United States, Miami	Connected	1.0 ms	1.1.1.1
South Africa, Johannesburg	Connected	2.0 ms	1.1.1.1

Albania, Tirana

Connected

223.0 ms

1.1.1.1

Australia, Sydney

Connected

1.0 ms

1.1.1.1

Bosnia and Herzegovina, Novi Travnik

Connected

18.0 ms

1.1.1.1

Bulgaria, Sofia

Connected

32.0 ms

1.1.1.1

Canada, Montreal

Connected

11.0 ms

1.1.1.1

Switzerland, Bern

Connected

1.0 ms

1.1.1.1

Switzerland, Zurich

Connected

19.0 ms

1.1.1.1

China, Hohhot

Connected

336.0 ms

1.1.1.1

Cyprus, Larnaca

Connected

2.0 ms

1.1.1.1

Germany, Nuernberg

Connected

15.0 ms

1.1.1.1

Germany, Frankfurt am Main

Connected

0.0 ms

1.1.1.1

Germany, Frankfurt am Main

Connected

1.0 ms

1.1.1.1

Germany, Frankfurt am Main

Connected

2.0 ms

1.1.1.1

Germany, Koblenz

Connected

20.0 ms

1.1.1.1

Germany, Frankfurt am Main

Connected

5.0 ms

1.1.1.1

Denmark, Glostrup Municipality

Connected

25.0 ms

1.1.1.1

Spain, Bilbao

Connected

42.0 ms

1.1.1.1

Spain, Barcelona

Connected

18.0 ms

1.1.1.1

Finland, Helsinki

Connected

5.0 ms

1.1.1.1

Finland, Helsinki

Connected

19.0 ms

1.1.1.1

France, Gravelines

Connected

5.0 ms

1.1.1.1

France, Paris

Connected

10.0 ms

1.1.1.1

United Kingdom, London

Connected

8.0 ms

1.1.1.1

Hong Kong, Hong Kong

Connected

6.0 ms

1.1.1.1

Croatia, Zagreb

Connected

30.0 ms

1.1.1.1

Hungary, Budapest

Connected

14.0 ms

1.1.1.1

Israel, Petach Tikwa

Connected

1.0 ms

1.1.1.1

Israel, Netanja

Connected

1.0 ms

1.1.1.1

Iran, Tehran

Connected

1.0 ms

1.1.1.1

Iran, Tehran

Connected

1.0 ms

1.1.1.1

Iceland, Reykjavik (Miðborg)

Connected

2.0 ms

1.1.1.1

Italy, Como

Connected

1.0 ms

1.1.1.1

Japan, Tokyo

Connected

1.0 ms

1.1.1.1

South Korea, Seoul

Connected

2.0 ms

1.1.1.1

Kazakhstan, Almaty

Connected

2.0 ms

1.1.1.1

Lithuania, Pilaite

Connected

73.0 ms

1.1.1.1

Latvia, Riga

Connected

31.0 ms

1.1.1.1

Moldova, Chisinau

Connected

70.0 ms

1.1.1.1

Netherlands, Amsterdam

Connected

1.0 ms

1.1.1.1

Netherlands, Amsterdam

Connected

3.0 ms

1.1.1.1

Netherlands, Amsterdam

Connected

1.0 ms

1.1.1.1

Netherlands, Amsterdam

Connected

1.0 ms

1.1.1.1

Netherlands, Eygelshoven

Connected

4.0 ms

1.1.1.1

Norway, Oslo

Connected

1.0 ms

1.1.1.1

Poland, Warsaw

Connected

16.0 ms

1.1.1.1

Romania, Bacău

Connected

53.0 ms

1.1.1.1

Romania, Bucharest

Connected

8.0 ms

1.1.1.1

Serbia, Belgrade

Connected

7.0 ms

1.1.1.1

Russia, Moscow

Connected

25.0 ms

1.1.1.1

Singapore, Singapore

Connected

2.0 ms

1.1.1.1

Tor, Onion

ERROR

-

1.1.1.1

Tor, Onion

ERROR

-

1.1.1.1

Tor, Onion

ERROR

-

1.1.1.1

Turkey, Istanbul

Connected

9.0 ms

1.1.1.1

Ukraine, Khmelnytskyi

Connected

6.0 ms

1.1.1.1

United States, Dallas

Connected

2.0 ms

1.1.1.1

United States, Los Angeles

Connected

1.0 ms

1.1.1.1

United States, Houston

Connected

7.0 ms

1.1.1.1

United States, Miami

Connected

1.0 ms

1.1.1.1

South Africa, Johannesburg

Connected

2.0 ms

1.1.1.1

Check TCP 1.1.1.1:80