Online latency checker
Measure HTTP reachability and rough latency from the browser before you ship or debug a site.
Note: This tool measures HTTP reachability with the Fetch API, not a real ICMP ping. The timing includes DNS, TCP, TLS, and server response time, which makes it a practical browser-side approximation of how a visitor experiences your site.
Recent checks
Latency basics
Low latency
Under 100 ms: great for interactive apps, live previews, and calls.
100-200 ms: usually still smooth for everyday browsing.
High latency
Over 300 ms: users begin to feel noticeable lag.
Over 500 ms: pages often feel slow and need investigation.
Frequently asked questions
Why is the latency higher than I expected?
Latency rises when the server is far away, the network is congested, the connection is unstable, or the origin itself is slow. The browser measurement also includes connection setup and server processing time.
What is TTFB?
Time to First Byte measures how long it takes for the browser to receive the first byte of the response. It is a useful indicator of both network conditions and backend responsiveness.