About RTT.ICU

RTT.ICU is a free toolkit for diagnosing network connectivity, latency, routing, and service availability from anywhere in the world. The aim is to give network engineers, developers, and site operators a single place to answer the question “is it down, is it slow, or is it just me?” without installing any software.

The tools run your tests from a distributed set of remote regions, so the results reflect what real users in those regions would experience, not just what a single server in one datacenter sees. You can test ping, traceroute, MTR, DNS lookups, HTTP reachability, IP lookups, and HTTP header inspection, all from the same interface.

Everything here is free and open-source. There are no accounts to create, no quotas behind a login, and no tracking of your test activity beyond the minimal server logs needed to keep the service running. We believe basic network observability should be accessible to everyone.

Each test is also available as a JSON API, so automated agents and scripts can query the same measurement engine directly. See llms.txt for the endpoints and guidance on how to call them.