Speed test Guides
Updated 23 September 2026
Speed test results are full of technical words. Here is what each one means, in plain English, and why it matters for what you actually do online.
The unit used for internet speeds. It is what your provider advertises and what the test displays.
The unit your browser shows while downloading. One byte is 8 bits, so:
| Advertised speed | Download speed |
|---|---|
| 8 Mbps | about 1 MB/s |
| 100 Mbps | about 12.5 MB/s |
| 500 Mbps | about 62.5 MB/s |
| 1 Gbps | about 125 MB/s |
This is the number one source of confusion: a file coming down at 12 MB/s on a 100 Mbps line is not a problem, it is the same thing expressed differently.
1 Gbps = 1,000 Mbps.
What you receive: web pages, video, downloads, updates. It is the figure providers put on the poster.
What you send: your image in a video call, photos, an online backup, a shared screen. On many cable and copper plans it is far lower than download.
Latency is how long data takes to make the round trip to a server. Ping is the everyday name for that measurement. It is counted in milliseconds: lower means a more responsive connection.
How much latency varies from one packet to the next. A decent average with heavy variation gives you a choppy video call or a stuttering game.
The share of data that never arrives and has to be resent. Above 1% consistently, calls drop out and games become hard work.
The shortest round trip observed during the test. Volt uses it for the ping figure because it shows the link's latency without one-off slowdowns.
Fibre carries light. FTTH means fibre all the way into the home: the best case. FTTB stops at the building and FTTC at the street cabinet, with the last stretch running over copper or coaxial cable, and that stretch's performance.
Internet over the copper phone line. Speed falls as the line to the exchange gets longer.
Internet over the cable television network. High download, more limited upload, bandwidth shared with the neighbourhood.
The generations of Wi-Fi. Each raises theoretical speed and the ability to handle many devices. Wi-Fi never improves the line itself; it can only cap it.
The Wi-Fi frequencies. 2.4 GHz reaches further and gets through walls better, but is crowded and slower. 5 GHz is faster at short range.
Queues building up in your router when something saturates the upload. Latency shoots up while speed still looks fine.
The theoretical maximum capacity of the link. Speed is what you actually get.
A router setting that prioritises certain devices or uses, such as the games console, when the line is busy.
Providers advertise a maximum, "up to". Real speed depends on your equipment, your setup and the time of day. There is always a gap; what matters is how big it is.
Because those are different units: one byte is 8 bits. 100 Mbps is about 12.5 MB/s, so your line is working normally.
Bandwidth is the link's theoretical maximum capacity; speed is what actually flows through at a given moment, limited by the network path and your own setup.
It depends on the use. For gaming and video calls, latency and its stability matter more. For downloading or watching in 4K, speed comes first.