Latency is the total time a packet needs to travel from your device to a server and back. It is the sum of four delays: propagation (distance), transmission (pushing bits onto the wire), queuing (waiting in router buffers), and processing (routing decisions at each hop).

Latency Test

Q: What are the four components of latency?

Propagation delay set by physical distance, transmission delay set by link speed, queuing delay from packets waiting in congested buffers, and processing delay from each router inspecting and forwarding the packet.

Q: What is a good latency?

Under 20 ms is excellent and ideal for competitive gaming and live calls, 20-50 ms is good for most uses, 50-100 ms is usable, and above 100 ms produces noticeable lag in real-time applications.

Q: Which part of my latency can I actually fix?

Propagation delay is physics and cannot be reduced, but queuing delay usually can: wired connections, Smart Queue Management, closer servers, and pausing background transfers all cut the avoidable portion of your round-trip time.

Latency is the total round-trip delay between your device and a server - The sum of propagation, transmission, queuing, and processing delays. Press GO to measure yours and see which part you can actually improve.

Latency Score Reference

Propagation Delay

Time for the signal to physically cross the distance to the server. Light in fibre covers ~200 km per millisecond - This part is set by geography.

Transmission Delay

Time to push every bit of a packet onto the wire. Negligible on fast links, but significant on slow DSL uploads and congested radio channels.

Queuing Delay

Time packets spend waiting in router buffers behind other traffic. The most variable component - And the main one you can reduce.

Processing Delay

Time each router and switch needs to inspect headers and pick the next hop. Usually microseconds, but it accumulates across 10-20 hops.

What is latency?

Latency is the total round-trip delay between your device and a server - Every millisecond from the moment a request leaves your network card to the moment the reply arrives back. A ping test reports this number, but latency itself is not a single thing: it's the sum of four distinct delays that behave very differently, and knowing which one dominates tells you whether your latency can be fixed at all.

What are the four components of latency?

Every round trip is built from the same four ingredients, applied at every hop along the path:

Propagation delay - The travel time imposed by distance. Signals move through fibre at roughly two-thirds the speed of light, so a 1,000 km path costs about 10 ms round-trip no matter how fast your plan is. This is the hard physics floor.
Transmission delay - The time to serialise a packet onto the link, set by link speed. A 1,500-byte packet takes 0.012 ms on gigabit Ethernet but over 1 ms on a 10 Mbps uplink, and Wi-Fi adds contention time on top.
Queuing delay - The time packets wait in router buffers behind other traffic. On an idle line it's near zero; during a big download an oversized buffer (bufferbloat) can add hundreds of milliseconds. This is the component that makes your latency fluctuate.
Processing delay - The time each router needs to read headers, check routing tables, and forward the packet. Modern hardware does this in microseconds, but a 15-hop path multiplies it.

A practical diagnostic: your minimum sample in the widget above approximates the fixed delays (propagation + transmission + processing), while the gap between minimum and maximum approximates queuing. A large gap means congestion or bufferbloat, not distance - And that is fixable. A consistently high minimum means the path itself is long, and only a closer server will help. Run the bufferbloat test to see how much queuing delay your connection adds under load.

What is a good latency?

Latency	Rating	What it feels like
Under 20 ms	Excellent	Ideal for competitive gaming, live calls, and remote desktop work.
20–50 ms	Good	Responsive for most gaming, browsing, video calls, and streaming.
50–100 ms	Usable	Fine for browsing and streaming, but fast games may feel delayed.
100+ ms	Poor	Noticeable lag in games, calls, screen sharing, and remote control apps.

For per-application thresholds and deeper context, see the ping test page and our guide to what counts as good ping.

Which part of my latency can I actually fix?

Queuing delay is the big win: enable Smart Queue Management (SQM/FQ-CoDel/CAKE) on your router and pause bulk transfers during latency-sensitive sessions.
Transmission delay on the first hop drops when you swap Wi-Fi for Ethernet, removing radio contention from every packet.
Propagation delay only shrinks by shortening the path - Choose the nearest game, VPN, or application server.
Processing delay falls when an overloaded consumer router is replaced or rebooted, and when a VPN's extra encryption hops are removed.
Re-test at different times of day: latency that only rises in the evening points to ISP congestion, not your home network.

For deeper troubleshooting, read what latency means, how to lower ping, and how to reduce jitter.