UDP has no handshake, so failures are easy to miss. Send a probe string to your UDP service and verify the reply to know it is really alive.
UDP is used for DNS, VoIP, streaming, VPNs and games precisely because it is fast and connectionless. The catch: nothing tells you when a UDP service is down unless you ask it something and wait for an answer.
A UDP monitor sends a string you define and checks the reply, which is the only reliable way to prove a UDP service is responding.
Every check is stored in a full log, so you can see exactly when and how something changed.
Define what to send and what a healthy reply contains.
DNS 53, WireGuard, game servers, custom services.
Track latency of the reply.
Verify reachability from several regions.
From sign-up to your first alert in a few minutes.
Choose the UDP service.
A string to send and one to expect back.
Be told when the reply stops arriving.
Sensible defaults get you started; every option below can be tuned per monitor.
| Setting | What it does |
|---|---|
| Domain / IP | The server to monitor. |
| Port | The UDP port. |
| String to send | Data to send to the server. |
| String to expect | Text the reply must contain. |
| Frequency | How often the check runs: 1 to 120 minutes. The Free plan checks from every 15 minutes; Premium from every minute. |
| Locations | Run the check from one or several of 9 locations: Spain, France, United Kingdom, USA (New York, Los Angeles), Australia, Singapore, Japan and Germany. |
| Notifications | Pick any of your pre-configured alert channels: e-mail, SMS, Telegram, Slack, Messenger, voice call, webhooks and more. |
| Status page | Make the statistics of this monitor public or private. |
| Tags | Group monitors with tags to keep large accounts tidy. |
| IP version | Force IPv4, IPv6, or let Upzilla use whichever is available. |
Check your own resolvers and authoritative servers.
Watch WireGuard or OpenVPN over UDP.
Keep SIP and media endpoints healthy.
Confirm players can reach the server.
Create as many notification methods as you like, even on the free plan.
With no connection there is no handshake to confirm. You have to send a probe and wait for a reply.
Then a reply-based check is not possible. Consider a TCP or ping check on the same host.
DNS 53, NTP 123, SNMP 161, WireGuard 51820. See the port numbers list for more.
Yes, choose any of the 9 locations.
No card required. 10 monitors of any type, free.