How do I check if a UDP port is open online?

Enter a host and UDP port (e.g. 8.8.8.8:53) in the UDP checker. The tool sends protocol-appropriate payloads from 65+ global nodes — for example, a real DNS query to port 53 or an NTP request to port 123 — and reports whether a valid response was received from each location.

Why does UDP port testing require a payload?

Unlike TCP, UDP has no handshake. An empty packet sent to most UDP services produces no response because the application is waiting for meaningful data before replying. The tool automatically injects the correct payload for known ports (DNS/53, NTP/123, SNMP/161, game servers/27015) to get a real, meaningful response.

How do I test if my VPN UDP port is reachable?

Enter your VPN server IP and port (typically UDP 1194 for OpenVPN or UDP 51820 for WireGuard) and run the UDP check. Results from multiple global nodes will show whether your VPN port is accessible worldwide or blocked by specific ISPs or regional networks.

Can I test game server ports with this UDP checker?

Yes. For Source Engine game servers (CS:GO, TF2, Rust) on port 27015, the tool automatically sends a valid Source Engine query packet. For other game servers, you can enter a custom hex payload in the advanced options. Results show which global regions can reach your game server.

Report for https:80 - Check-Host

Name: Check-Host https:80 UDP 端口可达性检测
Author: Check-Host

Location	Result	Time	IP Address
Albania, Tirana	DNS Error: No valid public IP found for https	-	-
Australia, Sydney	DNS Error: No valid public IP found for https	-	-
Bosnia and Herzegovina, Novi Travnik	DNS Error: No valid public IP found for https	-	-
Bulgaria, Sofia	DNS Error: No valid public IP found for https	-	-
Canada, Montreal	Node overloaded	-	-
Switzerland, Bern	DNS Error: No valid public IP found for https	-	-
Switzerland, Zurich	DNS Error: No valid public IP found for https	-	-
China, Hohhot	DNS Error: No valid public IP found for https	-	-
Cyprus, Larnaca	DNS Error: No valid public IP found for https	-	-
Germany, Nuernberg	DNS Error: No valid public IP found for https	-	-
Germany, Frankfurt am Main	DNS Error: No valid public IP found for https	-	-
Germany, Frankfurt am Main	DNS Error: No valid public IP found for https	-	-
Germany, Frankfurt am Main	DNS Error: No valid public IP found for https	-	-
Germany, Koblenz	DNS Error: No valid public IP found for https	-	-
Germany, Frankfurt am Main	DNS Error: No valid public IP found for https	-	-
Denmark, Glostrup Municipality	DNS Error: No valid public IP found for https	-	-
Spain, Bilbao	DNS Error: No valid public IP found for https	-	-
Spain, Barcelona	DNS Error: No valid public IP found for https	-	-
Finland, Helsinki	DNS Error: No valid public IP found for https	-	-
Finland, Helsinki	DNS Error: No valid public IP found for https	-	-
France, Gravelines	DNS Error: No valid public IP found for https	-	-
France, Paris	DNS Error: No valid public IP found for https	-	-
United Kingdom, London	DNS Error: No valid public IP found for https	-	-
Hong Kong, Hong Kong	DNS Error: No valid public IP found for https	-	-
Croatia, Zagreb	DNS Error: No valid public IP found for https	-	-
Hungary, Budapest	DNS Error: No valid public IP found for https	-	-
Israel, Petach Tikwa	DNS Error: No valid public IP found for https	-	-
Israel, Netanja	DNS Error: No valid public IP found for https	-	-
Iran, Tehran	DNS Error: No valid public IP found for https	-	-
Iran, Tehran	DNS Error: No valid public IP found for https	-	-
Iceland, Reykjavik (Miðborg)	DNS Error: No valid public IP found for https	-	-
Italy, Como	DNS Error: No valid public IP found for https	-	-
Japan, Tokyo	DNS Error: No valid public IP found for https	-	-
South Korea, Seoul	DNS Error: No valid public IP found for https	-	-
Kazakhstan, Almaty	DNS Error: No valid public IP found for https	-	-
Lithuania, Pilaite	DNS Error: No valid public IP found for https	-	-
Latvia, Riga	DNS Error: No valid public IP found for https	-	-
Moldova, Chisinau	DNS Error: No valid public IP found for https	-	-
Netherlands, Amsterdam	DNS Error: No valid public IP found for https	-	-
Netherlands, Amsterdam	DNS Error: No valid public IP found for https	-	-
Netherlands, Amsterdam	DNS Error: No valid public IP found for https	-	-
Netherlands, Amsterdam	DNS Error: No valid public IP found for https	-	-
Netherlands, Eygelshoven	DNS Error: No valid public IP found for https	-	-
Norway, Oslo	DNS Error: No valid public IP found for https	-	-
Poland, Warsaw	DNS Error: No valid public IP found for https	-	-
Romania, Bacău	DNS Error: No valid public IP found for https	-	-
Romania, Bucharest	DNS Error: No valid public IP found for https	-	-
Serbia, Belgrade	DNS Error: No valid public IP found for https	-	-
Russia, Moscow	DNS Error: No valid public IP found for https	-	-
Singapore, Singapore	DNS Error: No valid public IP found for https	-	-
Tor, Onion	UDP checks unavailable: SOCKS5 proxy does not support UDP ASSOCIATE	-	https
Tor, Onion	UDP checks unavailable: SOCKS5 proxy does not support UDP ASSOCIATE	-	https
Tor, Onion	UDP checks unavailable: SOCKS5 proxy does not support UDP ASSOCIATE	-	https
Turkey, Istanbul	DNS Error: No valid public IP found for https	-	-
Ukraine, Khmelnytskyi	DNS Error: No valid public IP found for https	-	-
United States, Dallas	DNS Error: No valid public IP found for https	-	-
United States, Los Angeles	DNS Error: No valid public IP found for https	-	-
United States, Houston	DNS Error: No valid public IP found for https	-	-
United States, Miami	DNS Error: No valid public IP found for https	-	-
South Africa, Johannesburg	DNS Error: No valid public IP found for https	-	-

Albania, Tirana

DNS Error: No valid public IP found for https

-

Australia, Sydney

DNS Error: No valid public IP found for https

-

Bosnia and Herzegovina, Novi Travnik

DNS Error: No valid public IP found for https

-

Bulgaria, Sofia

DNS Error: No valid public IP found for https

-

Canada, Montreal

Node overloaded

-

Switzerland, Bern

DNS Error: No valid public IP found for https

-

Switzerland, Zurich

DNS Error: No valid public IP found for https

-

China, Hohhot

DNS Error: No valid public IP found for https

-

Cyprus, Larnaca

DNS Error: No valid public IP found for https

-

Germany, Nuernberg

DNS Error: No valid public IP found for https

-

Germany, Frankfurt am Main

DNS Error: No valid public IP found for https

-

Germany, Frankfurt am Main

DNS Error: No valid public IP found for https

-

Germany, Frankfurt am Main

DNS Error: No valid public IP found for https

-

Germany, Koblenz

DNS Error: No valid public IP found for https

-

Germany, Frankfurt am Main

DNS Error: No valid public IP found for https

-

Denmark, Glostrup Municipality

DNS Error: No valid public IP found for https

-

Spain, Bilbao

DNS Error: No valid public IP found for https

-

Spain, Barcelona

DNS Error: No valid public IP found for https

-

Finland, Helsinki

DNS Error: No valid public IP found for https

-

Finland, Helsinki

DNS Error: No valid public IP found for https

-

France, Gravelines

DNS Error: No valid public IP found for https

-

France, Paris

DNS Error: No valid public IP found for https

-

United Kingdom, London

DNS Error: No valid public IP found for https

-

Hong Kong, Hong Kong

DNS Error: No valid public IP found for https

-

Croatia, Zagreb

DNS Error: No valid public IP found for https

-

Hungary, Budapest

DNS Error: No valid public IP found for https

-

Israel, Petach Tikwa

DNS Error: No valid public IP found for https

-

Israel, Netanja

DNS Error: No valid public IP found for https

-

Iran, Tehran

DNS Error: No valid public IP found for https

-

Iran, Tehran

DNS Error: No valid public IP found for https

-

Iceland, Reykjavik (Miðborg)

DNS Error: No valid public IP found for https

-

Italy, Como

DNS Error: No valid public IP found for https

-

Japan, Tokyo

DNS Error: No valid public IP found for https

-

South Korea, Seoul

DNS Error: No valid public IP found for https

-

Kazakhstan, Almaty

DNS Error: No valid public IP found for https

-

Lithuania, Pilaite

DNS Error: No valid public IP found for https

-

Latvia, Riga

DNS Error: No valid public IP found for https

-

Moldova, Chisinau

DNS Error: No valid public IP found for https

-

Netherlands, Amsterdam

DNS Error: No valid public IP found for https

-

Netherlands, Amsterdam

DNS Error: No valid public IP found for https

-

Netherlands, Amsterdam

DNS Error: No valid public IP found for https

-

Netherlands, Amsterdam

DNS Error: No valid public IP found for https

-

Netherlands, Eygelshoven

DNS Error: No valid public IP found for https

-

Norway, Oslo

DNS Error: No valid public IP found for https

-

Poland, Warsaw

DNS Error: No valid public IP found for https

-

Romania, Bacău

DNS Error: No valid public IP found for https

-

Romania, Bucharest

DNS Error: No valid public IP found for https

-

Serbia, Belgrade

DNS Error: No valid public IP found for https

-

Russia, Moscow

DNS Error: No valid public IP found for https

-

Singapore, Singapore

DNS Error: No valid public IP found for https

-

Tor, Onion

UDP checks unavailable: SOCKS5 proxy does not support UDP ASSOCIATE

-

https

Tor, Onion

UDP checks unavailable: SOCKS5 proxy does not support UDP ASSOCIATE

-

https

Tor, Onion

UDP checks unavailable: SOCKS5 proxy does not support UDP ASSOCIATE

-

https

Turkey, Istanbul

DNS Error: No valid public IP found for https

-

Ukraine, Khmelnytskyi

DNS Error: No valid public IP found for https

-

United States, Dallas

DNS Error: No valid public IP found for https

-

United States, Los Angeles

DNS Error: No valid public IP found for https

-

United States, Houston

DNS Error: No valid public IP found for https

-

United States, Miami

DNS Error: No valid public IP found for https

-

South Africa, Johannesburg

DNS Error: No valid public IP found for https

-

report.report_types.udp https:80