Network latency is the time delay between sending a request and receiving a response. It is measured in milliseconds (ms) and affects how fast and responsive websites feel, regardless of your connection's bandwidth. You can see your current latency to Cloudflare's nearest edge node on whatsmy.fyi.
What Is RTT (Round-Trip Time)?
RTT (Round-Trip Time) is the time it takes for a packet to travel from your device to a server and back to your device. It is the most common way to measure latency.
When you send an HTTP request to a website, the browser waits for the server to acknowledge receipt before it can start sending data. Every RTT adds a waiting period. For a typical page load with multiple resources, multiple RTTs accumulate β which is one reason high-latency connections feel slow even on fast internet plans.
RTT is also called ping time in gaming and network diagnostics. Theping command measures RTT to a given host.
Latency vs. Bandwidth: What Is the Difference?
These two concepts are often confused:
- Bandwidth: How much data can flow through your connection per second (e.g., 1 Gbps). Think of it as the width of a pipe.
- Latency: How long it takes for data to start flowing after a request is sent. Think of it as the length of the pipe.
A high-bandwidth, high-latency connection (e.g., satellite internet: 100 Mbps but 600ms RTT) feels sluggish for web browsing, video calling, and gaming β even though it can transfer large files quickly. A low-bandwidth, low-latency connection (e.g., a 5 Mbps DSL with 10ms RTT) feels much more responsive for interactive tasks.
What Causes High Latency?
- Physical distance: Data travels at approximately 200,000 km/s through fibre optic cables (about 2/3 the speed of light). A server on the other side of the world is simply far away.
- Network congestion: Overloaded routers and switches introduce queuing delays.
- Satellite internet: Geostationary satellites orbit at ~35,000 km altitude, adding at least 240ms to every RTT. Low-earth orbit satellites (Starlink) reduce this to 20β50ms.
- VPN routing: VPNs add latency by routing traffic through an additional server. A VPN server on another continent can add 100ms+ to every request.
- Wireless interference: Wi-Fi and mobile connections add variable latency due to wireless medium contention and interference.
How Cloudflare Edge Nodes Reduce Latency
Cloudflare operates one of the world's largest CDN (Content Delivery Network) networks, with edge nodes in over 300 cities. Instead of routing your request to a server in one country, Cloudflare processes it at the nearest edge location.
The "Latency & Datacenter" card on whatsmy.fyi shows the Cloudflare edge node that processed your request and your RTT to that node. The whatsmy.fyi API runs on Cloudflare Workers β so it executes at the edge, in the same data center that received your request, with no additional network hop to a distant origin server.
This architecture delivers sub-50ms TTFB (Time to First Byte) for almost all users worldwide.
Latency and HTTP/3
One of the key advantages of HTTP/3 (QUIC) is reduced latency. QUIC combines the TCP and TLS handshakes into a single 1-RTT exchange (or even 0-RTT for repeated connections), cutting the time to first byte. For high-latency connections, this can make a noticeable difference.
Frequently Asked Questions
What is a good ping for web browsing?
For web browsing, latency under 100ms is generally imperceptible. Under 30ms feels instant. For online gaming, under 50ms is ideal. For video calling, under 150ms is acceptable.
What is the RTT shown on whatsmy.fyi?
It is the TCP RTT (Round-Trip Time) from your device to the Cloudflare edge node that processed your request, as measured by Cloudflare at the server level. It is typically very close to, but not identical to, the ping latency you would measure yourself.
Why does my latency spike sometimes?
Latency spikes (jitter) are usually caused by network congestion, background traffic on your connection, or Wi-Fi interference. A spike does not mean your connection is broken β it is normal variability. Consistent high latency is more concerning than occasional spikes.
