Glossary

Plain-language answers to "what does Mbps mean?", "what's the difference between ping and jitter?", and other common speed test questions.

Download speed

How fast data moves from a server to your device — the number that matters most for streaming, browsing, and downloading files. Measured in megabits per second (Mbps).

Upload speed

How fast data moves from your device out to the internet. Matters for video calls, sending large files, and live streaming. Most home connections are built to upload slower than they download.

Ping (latency)

The round-trip time for a small signal to reach a server and come back, measured in milliseconds (ms). Lower is better — it's what makes a connection feel "responsive," and matters most for gaming and video calls.

Jitter

How much your ping varies from one moment to the next. Low jitter means a steady, predictable connection; high jitter can cause stuttering in calls or games even if your average ping looks fine.

Packet loss

The percentage of data that never arrives at all during a transfer. Even small amounts of packet loss can cause choppy video calls or dropped connections in games, regardless of how fast your download speed is.

Mbps

Megabits per second — the standard unit for internet speed. Not the same as MB/s (megabytes per second): a megabyte is 8 megabits, so a connection showing "100 Mbps" is roughly "12.5 MB/s" for actual file transfers.

MB/s

Megabytes per second — how file transfer speed is usually shown by your operating system or download manager. To convert from Mbps, divide by 8.