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	405.0 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	31.0 ms	1.1.1.1
Canada, Montreal	Connected	8.0 ms	1.1.1.1
Switzerland, Bern	Connected	1.0 ms	1.1.1.1
Switzerland, Zurich	Connected	26.0 ms	1.1.1.1
China, Hohhot	Connected	315.0 ms	1.1.1.1
Cyprus, Larnaca	Connected	2.0 ms	1.1.1.1
Germany, Nuernberg	Connected	20.0 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	1.0 ms	1.1.1.1
Germany, Koblenz	Connected	16.0 ms	1.1.1.1
Germany, Frankfurt am Main	Connected	4.0 ms	1.1.1.1
Denmark, Glostrup Municipality	Connected	31.0 ms	1.1.1.1
Spain, Bilbao	Connected	42.0 ms	1.1.1.1
Spain, Barcelona	Connected	17.0 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	50.0 ms	1.1.1.1
United Kingdom, London	Connected	8.0 ms	1.1.1.1
Hong Kong, Hong Kong	Connected	7.0 ms	1.1.1.1
Croatia, Zagreb	Connected	28.0 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	2.0 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	1.0 ms	1.1.1.1
Kazakhstan, Almaty	Connected	2.0 ms	1.1.1.1
Lithuania, Pilaite	Connected	95.0 ms	1.1.1.1
Latvia, Riga	Connected	129.0 ms	1.1.1.1
Moldova, Chisinau	Connected	145.0 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	0.0 ms	1.1.1.1
Poland, Warsaw	Connected	17.0 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	5.0 ms	1.1.1.1
Russia, Moscow	Connected	21.0 ms	1.1.1.1
Singapore, Singapore	Connected	245.0 ms	1.1.1.1
Tor, Onion	Connected	92.0 ms	1.1.1.1
Tor, Onion	Connected	326.0 ms	1.1.1.1
Tor, Onion	Connected	249.0 ms	1.1.1.1
Turkey, Istanbul	Connected	9.0 ms	1.1.1.1
Ukraine, Khmelnytskyi	Connected	5.0 ms	1.1.1.1
United States, Dallas	Connected	1.0 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

405.0 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

31.0 ms

1.1.1.1

Canada, Montreal

Connected

8.0 ms

1.1.1.1

Switzerland, Bern

Connected

1.0 ms

1.1.1.1

Switzerland, Zurich

Connected

26.0 ms

1.1.1.1

China, Hohhot

Connected

315.0 ms

1.1.1.1

Cyprus, Larnaca

Connected

2.0 ms

1.1.1.1

Germany, Nuernberg

Connected

20.0 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

1.0 ms

1.1.1.1

Germany, Koblenz

Connected

16.0 ms

1.1.1.1

Germany, Frankfurt am Main

Connected

4.0 ms

1.1.1.1

Denmark, Glostrup Municipality

Connected

31.0 ms

1.1.1.1

Spain, Bilbao

Connected

42.0 ms

1.1.1.1

Spain, Barcelona

Connected

17.0 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

50.0 ms

1.1.1.1

United Kingdom, London

Connected

8.0 ms

1.1.1.1

Hong Kong, Hong Kong

Connected

7.0 ms

1.1.1.1

Croatia, Zagreb

Connected

28.0 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

2.0 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

1.0 ms

1.1.1.1

Kazakhstan, Almaty

Connected

2.0 ms

1.1.1.1

Lithuania, Pilaite

Connected

95.0 ms

1.1.1.1

Latvia, Riga

Connected

129.0 ms

1.1.1.1

Moldova, Chisinau

Connected

145.0 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

0.0 ms

1.1.1.1

Poland, Warsaw

Connected

17.0 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

5.0 ms

1.1.1.1

Russia, Moscow

Connected

21.0 ms

1.1.1.1

Singapore, Singapore

Connected

245.0 ms

1.1.1.1

Tor, Onion

Connected

92.0 ms

1.1.1.1

Tor, Onion

Connected

326.0 ms

1.1.1.1

Tor, Onion

Connected

249.0 ms

1.1.1.1

Turkey, Istanbul

Connected

9.0 ms

1.1.1.1

Ukraine, Khmelnytskyi

Connected

5.0 ms

1.1.1.1

United States, Dallas

Connected

1.0 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