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.

Rapport pour time.nist.gov:123

Info Ping HTTP TCP UDP MTR DNS

report.report_types.udp time.nist.gov:123

report.used_payload:

0x1b0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

Vérifié le Apr 21, 2026 00:31:41 UTC |

| Revérifier |

Emplacement	Résultat	Temps	Adresse IP
Albania, Tirana	OPEN	182.0 ms	132.163.97.4
Australia, Sydney	OPEN	167.0 ms	132.163.96.6
Bosnia and Herzegovina, Novi Travnik	OPEN	151.0 ms	132.163.97.3
Bulgaria, Sofia	OPEN	147.0 ms	132.163.96.6
Canada, Montreal	OPEN	42.0 ms	132.163.96.6
Switzerland, Bern	OPEN	131.0 ms	132.163.97.3
Chile, Santiago	OPEN	154.0 ms	132.163.97.4
China, Hohhot	OPEN	275.0 ms	132.163.96.3
Germany, Nuernberg	OPEN	135.0 ms	132.163.97.3
Germany, Frankfurt am Main	OPEN	129.0 ms	132.163.96.3
Germany, Frankfurt am Main	Timeout	-	132.163.97.2
Germany, Limburg	OPEN	131.0 ms	132.163.96.4
Germany, Frankfurt am Main	OPEN	93.0 ms	129.6.15.26
Germany, Duesseldorf	OPEN	121.0 ms	132.163.96.2
Denmark, Glostrup Municipality	OPEN	147.0 ms	132.163.97.2
Spain, Bilbao	OPEN	158.0 ms	132.163.97.1
Finland, Helsinki	OPEN	120.0 ms	129.6.15.25
Finland, Helsinki	OPEN	149.0 ms	132.163.97.1
France, Gravelines	OPEN	124.0 ms	132.163.96.2
France, Paris	OPEN	96.0 ms	129.6.15.25
United Kingdom, London	OPEN	124.0 ms	132.163.96.1
Georgia, Tbilisi	UDP checks unavailable: SOCKS5 proxy does not support UDP ASSOCIATE	-	time.nist.gov
Greece, Athens	UDP checks unavailable: SOCKS5 proxy does not support UDP ASSOCIATE	-	time.nist.gov
Hong Kong, Hong Kong	Timeout	-	132.163.97.1
Croatia, Zagreb	OPEN	148.0 ms	132.163.96.2
Hungary, Budapest	OPEN	161.0 ms	132.163.96.6
Indonesia, Jakarta	OPEN	244.0 ms	129.6.15.25
Israel, Petach Tikwa	OPEN	173.0 ms	132.163.96.1
Israel, Netanja	OPEN	180.0 ms	132.163.96.1
India, New Delhi	OPEN	252.0 ms	132.163.96.2
Iceland, Reykjavik (Miðborg)	OPEN	164.0 ms	132.163.96.1
Italy, Como	OPEN	140.0 ms	132.163.96.3
Kuwait, Kuwait City	UDP checks unavailable: SOCKS5 proxy does not support UDP ASSOCIATE	-	time.nist.gov
Lithuania, Pilaite	OPEN	175.0 ms	132.163.97.4
Latvia, Riga	OPEN	183.0 ms	132.163.96.2
Moldova, Chisinau	OPEN	197.0 ms	132.163.96.3
Netherlands, Amsterdam	OPEN	125.0 ms	132.163.97.3
Netherlands, Amsterdam	OPEN	120.0 ms	132.163.96.1
Netherlands, Amsterdam	OPEN	124.0 ms	132.163.96.1
Netherlands, Amsterdam	OPEN	120.0 ms	132.163.96.1
Norway, Oslo	OPEN	143.0 ms	132.163.97.4
Poland, Warsaw	OPEN	126.0 ms	129.6.15.25
Romania, Bacău	OPEN	161.0 ms	132.163.96.1
Romania, Bucharest	Timeout	-	132.163.97.4
Serbia, Belgrade	OPEN	195.0 ms	132.163.97.3
Russia, St Petersburg	OPEN	153.0 ms	132.163.97.3
Singapore, Singapore	OPEN	209.0 ms	132.163.97.4
Turkey, Istanbul	OPEN	168.0 ms	132.163.97.6
Taiwan, Taipei	Timeout	-	132.163.97.1
United States, Miami	Timeout	-	132.163.96.1
United States, Dallas	OPEN	44.0 ms	132.163.97.1
United States, Kansas City	OPEN	24.0 ms	132.163.97.6
United States, Dallas	OPEN	30.0 ms	132.163.97.2
South Africa, Johannesburg	OPEN	262.0 ms	132.163.96.4