A video call freezing just as you need to speak, pages taking ages to load, or a gaming download that never seems to finish are all reasons to check your connection. Knowing how to test broadband speed properly helps you separate a genuine broadband fault from a WiFi, device or network issue – and gives you useful evidence if you need to contact your provider.
A single speed test result is only a snapshot. Your result can change depending on where you test, which device you use, what other people are doing online and the time of day. A careful test takes only a few minutes, but it can save hours of guesswork.
What a broadband speed test actually measures
Most speed tests show three main figures: download speed, upload speed and ping. They are normally shown in Mbps, meaning megabits per second. This is not the same as MBps, or megabytes per second, which may appear when you download a file. Eight megabits equal one megabyte, so a 100 Mbps connection can theoretically download at roughly 12.5 MB per second before allowing for overheads.
Download speed affects streaming, browsing, software updates, downloading files and receiving data during video calls. Upload speed matters when you send large files, back up photos to the cloud, host video meetings or use CCTV cameras that upload footage remotely. Ping, also called latency, is the delay between your device and a server. Lower is generally better, especially for online gaming, voice calls and remote desktop work.
Some tests also show jitter, which measures how much the delay varies. A high or inconsistent jitter result can make a video call sound broken even if the download speed looks healthy.
How to test broadband speed accurately
For the clearest starting point, test with a laptop or desktop connected directly to your router using an Ethernet cable. This checks the broadband arriving at your property without WiFi signal strength getting in the way. If the wired result is good but WiFi is poor elsewhere in the building, your broadband line may be fine – the wireless network needs attention.
Before running the test, pause any large downloads, cloud backups, console updates and streaming on the device you are using. If possible, ask other users to stop heavy internet use for a few minutes. A household with several people watching 4K television, gaming and working from home can use a significant amount of available bandwidth at once.
Then follow this practical process:
- Restart the router only if it has been running unusually slowly or has lost connection. Wait until it has fully reconnected before testing.
- Close unnecessary browser tabs, applications and VPN software on the test device. A VPN can reduce speed or add latency because traffic is travelling through another server.
- Run a reputable speed test while connected by Ethernet. Record the download, upload, ping and the time of the test.
- Repeat the test two or three times, leaving a minute between each result. One unusually low reading may be a temporary issue.
- Test again over WiFi in the room where you normally work, stream or game. This comparison shows whether the issue is with the broadband service or wireless coverage.
Do not judge the connection on one test taken late in the evening. Run the same checks at different times, such as morning, afternoon and evening, particularly if the problem seems worse after work or school. Keep a simple note of the results for two or three days if speeds vary widely.
Test close to the router, then where the problem happens
A strong WiFi result beside the router does not prove that the connection is good in a bedroom, loft office or garden office. Thick walls, foil-backed insulation, mirrors, metal fittings and neighbouring wireless networks can weaken or interfere with the signal.
Test in the affected room using the same device. If the wired result is 150 Mbps, the WiFi result beside the router is 140 Mbps, but it drops to 12 Mbps in your office, the issue is coverage rather than the incoming broadband speed. Repositioning the router, changing WiFi channels, using a mesh system or installing a wired access point may be a better fix than changing broadband package.
Compare your result with the right expectation
Check the speed estimate supplied with your broadband package, but read it carefully. Providers may advertise an average download speed, while the speed guaranteed to your individual address can be lower. Fibre-to-the-property connections usually provide more consistent speeds than older copper-based services, but the available service depends on your location and installation.
Your required speed also depends on what you do. Basic email and web browsing use very little bandwidth. A home with several people streaming high-definition video, taking video calls and gaming needs more capacity. For a small business, upload speed can be just as important as download speed if staff use cloud storage, shared files, hosted phones, remote access or off-site backups.
A result slightly below the advertised headline figure is not automatically a fault. The key question is whether the connection is consistently below the estimate for your line, or whether poor performance occurs at the same time as dropouts, high ping, failed calls or unreliable WiFi.
Why your broadband speed result may be slow
Slow results have several possible causes, and changing provider is not always the answer. Start with the difference between a line problem and a local network problem.
If an Ethernet test directly from the router is much lower than expected, check whether the router is reporting connection errors or frequent dropouts. A damaged phone line, a problem with the external network, an ageing router or a fault at the provider can all affect the result. If the speed has fallen suddenly compared with previous tests, record your figures and contact the provider with the dates and times.
If Ethernet is performing well but WiFi is slow, move the router into an open, central position where practical. Avoid placing it inside a cupboard, behind a television, on the floor or beside cordless phone bases, microwaves and other electronics. The 2.4 GHz WiFi band travels further but is often busier. The 5 GHz band can offer faster speeds at shorter distances. Newer routers may also use 6 GHz, although compatible devices are required.
Older laptops, phones and tablets can be another limit. A device with an older WiFi standard may not reach the speeds available from a modern fibre connection. Likewise, a poor-quality Ethernet cable, an old network adapter or a USB hub can reduce wired performance.
Check for hidden network use
Unexpected traffic is common in busy homes and offices. Cloud photo backup, operating system updates, security camera uploads, game downloads and file synchronisation can all run quietly in the background. Review connected devices in your router settings and look for equipment you do not recognise.
If you suspect someone else is using your WiFi, change the wireless password and use a strong, unique passphrase. Make sure the router is using current security settings rather than an outdated option. For a business, separate guest WiFi from staff devices and critical equipment where possible.
When a speed test points to a wider IT issue
Broadband speed is only one part of a reliable connection. A fast test result will not resolve a laptop with malware, a badly configured VPN, an overloaded office network or poor cabling. Equally, a slow test on one computer may point to that machine rather than the router.
Try the same test on a second device. If every device is slow in the same location, focus on the broadband or WiFi setup. If only one device struggles, it may need software checks, driver updates, virus removal or hardware attention. For offices, intermittent problems can also come from network switches, access points, cabling, firewall settings or too many devices sharing inadequate equipment.
A2z Computer Solutions provides practical WiFi, broadband and network support across London for homes and businesses. An engineer can test the connection at the router, assess wireless coverage, identify device or cabling faults and help you get to the real cause without unnecessary disruption.
If your results are consistently poor on a wired connection, save the evidence and raise it with your provider. If the line is healthy but your home or office still has dead spots, dropouts or slow rooms, the right network adjustment can make the connection feel completely different where you actually use it.