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.

Report for cloudflare.com:80

Info Ping HTTP TCP UDP MTR DNS

report.report_types.udp cloudflare.com:80

Checked Apr 22, 2026 08:47:00 UTC |

| Check again |

Location	Result	Time	IP Address
Albania, Tirana	Timeout	-	104.16.133.229
Australia, Sydney	Timeout	-	104.16.132.229
Bosnia and Herzegovina, Novi Travnik	Timeout	-	104.16.132.229
Bulgaria, Sofia	Timeout	-	104.16.133.229
Canada, Montreal	Timeout	-	104.16.132.229
Switzerland, Bern	Timeout	-	104.16.133.229
Chile, Santiago	Timeout	-	104.16.132.229
China, Hohhot	Timeout	-	104.16.132.229
Germany, Nuernberg	Timeout	-	104.16.132.229
Germany, Frankfurt am Main	Timeout	-	104.16.132.229
Germany, Frankfurt am Main	Timeout	-	104.16.132.229
Germany, Limburg	Timeout	-	104.16.132.229
Germany, Frankfurt am Main	Timeout	-	104.16.132.229
Germany, Duesseldorf	Timeout	-	104.16.133.229
Denmark, Glostrup Municipality	Timeout	-	104.16.132.229
Spain, Bilbao	Timeout	-	104.16.133.229
Finland, Helsinki	Timeout	-	104.16.132.229
Finland, Helsinki	Timeout	-	104.16.132.229
France, Gravelines	Timeout	-	104.16.132.229
France, Paris	Timeout	-	104.16.132.229
United Kingdom, London	Timeout	-	104.16.132.229
Georgia, Tbilisi	UDP checks unavailable: SOCKS5 proxy does not support UDP ASSOCIATE	-	cloudflare.com
Greece, Athens	UDP checks unavailable: SOCKS5 proxy does not support UDP ASSOCIATE	-	cloudflare.com
Hong Kong, Hong Kong	Timeout	-	104.16.133.229
Croatia, Zagreb	Timeout	-	104.16.132.229
Hungary, Budapest	Timeout	-	104.16.132.229
Indonesia, Jakarta	Timeout	-	104.16.132.229
Israel, Petach Tikwa	Timeout	-	104.16.132.229
Israel, Netanja	Timeout	-	104.16.132.229
India, New Delhi	Timeout	-	104.16.133.229
Iceland, Reykjavik (Miðborg)	Timeout	-	104.16.133.229
Italy, Como	Timeout	-	104.16.132.229
Kuwait, Kuwait City	UDP checks unavailable: SOCKS5 proxy does not support UDP ASSOCIATE	-	cloudflare.com
Lithuania, Pilaite	Timeout	-	104.16.132.229
Latvia, Riga	Timeout	-	104.16.132.229
Moldova, Chisinau	Timeout	-	104.16.132.229
Netherlands, Amsterdam	Timeout	-	104.16.132.229
Netherlands, Amsterdam	Timeout	-	104.16.133.229
Netherlands, Amsterdam	Timeout	-	104.16.133.229
Netherlands, Amsterdam	Timeout	-	104.16.132.229
Norway, Oslo	Timeout	-	104.16.133.229
Poland, Warsaw	Timeout	-	104.16.133.229
Romania, Bacău	Timeout	-	104.16.133.229
Romania, Bucharest	Timeout	-	104.16.132.229
Serbia, Belgrade	Timeout	-	104.16.133.229
Russia, St Petersburg	Timeout	-	104.16.133.229
Singapore, Singapore	Timeout	-	104.16.132.229
Turkey, Istanbul	Timeout	-	104.16.133.229
Taiwan, Taipei	Timeout	-	104.16.133.229
United States, Miami	Timeout	-	104.16.132.229
United States, Dallas	Timeout	-	104.16.133.229
United States, Kansas City	Timeout	-	104.16.133.229
United States, Dallas	Timeout	-	104.16.133.229
South Africa, Johannesburg	Timeout	-	104.16.133.229