Download speed measures how quickly data reaches your device. Upload speed measures how quickly data leaves it. Both are normally shown in megabits per second, or Mbps.
Download speed affects activities such as opening websites, watching streamed video, receiving files and downloading games. A higher download speed means more data can reach your home each second.
The benefit is most noticeable when several people use the connection at once or when downloading a large file.
Upload speed affects video calls, sending attachments, backing up photos, posting video and uploading work to cloud services.
It is particularly important for people who regularly send large files, use cloud backup, livestream, work from home or run internet-connected security cameras.
Mbps stands for megabits per second. It measures the rate at which data can travel across a connection.
The small “b” matters. Broadband speed is normally measured in megabits, while file sizes are often shown in megabytes, written as MB. There are eight bits in one byte, so the numbers are related but not interchangeable.
A higher speed gives your household more capacity and can shorten large downloads. It does not automatically improve every online experience.
A slow device, weak wifi, distant server or high latency can still affect performance. The best package is one that gives the household enough capacity at busy times without paying for speed it will not use.
Latency is the time taken for data to travel to a destination and back. It is commonly measured in milliseconds, or ms. A lower result generally means a more responsive connection.
Latency matters for online gaming, voice calls and video meetings. Extra Mbps does not always solve a latency problem.
Advertised package speeds and results on one device measure different things. A test can be affected by:
Follow our accurate speed-test guide before drawing conclusions from a single result.
Consider the number of simultaneous users, streaming quality, video calls, gaming, large downloads and cloud activity. Our broadband speed guide will help you match those needs to a sensible speed range.
Find the right broadband speed for you here
