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 50+ 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.

t1-tor-2.check-host.eu:80 の UDP ポートチェック

Name: Check-Host t1-tor-2.check-host.eu:80 UDP ポート到達性チェック
Author: Check-Host

詳細設定

世界地図を表示

詳細設定（カスタムペイロード）

空欄の場合は既知のポート（DNS、NTP、SNMP 等）のプローブを自動検出します。

Info Ping HTTP TCP UDP MTR DNS

UDP チェック t1-tor-2.check-host.eu:80

パーマリンク |

拠点	結果	応答時間	IP アドレス
Albania, Tirana
Australia, Sydney
Bosnia and Herzegovina, Novi Travnik
Bulgaria, Sofia
Canada, Montreal
Switzerland, Bern
Chile, Santiago
China, Hohhot
Germany, Nuernberg
Germany, Frankfurt am Main
Germany, Frankfurt am Main
Germany, Limburg
Germany, Frankfurt am Main
Germany, Duesseldorf
Denmark, Glostrup Municipality
Spain, Bilbao
Finland, Helsinki
Finland, Helsinki
France, Gravelines
France, Paris
United Kingdom, London
Georgia, Tbilisi
Hong Kong, Hong Kong
Croatia, Zagreb
Hungary, Budapest
Indonesia, Jakarta
Israel, Petach Tikwa
Israel, Netanja
India, New Delhi
Iceland, Reykjavik (Miðborg)
Italy, Como
Lithuania, Pilaite
Latvia, Riga
Moldova, Chisinau
Netherlands, Amsterdam
Netherlands, Amsterdam
Netherlands, Amsterdam
Netherlands, Amsterdam
Norway, Oslo
Poland, Warsaw
Romania, Bacău
Romania, Bucharest
Serbia, Belgrade
Russia, Moscow
Saudi Arabia, Riyadh
Singapore, Singapore
Tor, Onion
Tor, Onion
Tor, Onion
Turkey, Istanbul
Taiwan, Taipei
United States, Miami
United States, Dallas
United States, Kansas City
United States, Dallas
South Africa, Johannesburg