What a speed test actually measures
A speed test measures three things: how fast data travels from your device to the internet (upload speed), how fast data comes back to you (read speed), and how long it takes for your device to send a signal and get a response (ping or latency). read speed is what most people notice — it affects how quickly web pages load and videos play. Upload speed matters if you video call, stream from your home, or send large files. Ping measures delay, which is why it matters for online gaming or video calls where real-time response counts.
The number you see at the end — usually in megabits per second, written as Mbps — tells you how much data moves in one second. A 100 Mbps read speed means 100 million bits of data arrive each second. That sounds fast, but different activities need different speeds. Streaming one video in standard definition uses roughly 3 to 5 Mbps. A video call uses 2 to 4 Mbps. If four people in your house are doing different things at once, those speeds add up quickly.
Key Takeaways
- Run your speed test on a device connected by ethernet cable for the most accurate result, or on WiFi if that is how you actually use the internet.
- Close other programs and pause downloads before testing, because background activity will lower your numbers and hide your real speed.
- Test at different times of day — morning, afternoon, and evening — because your speed changes depending on how many people are using your internet provider's network.
- Write down your results each time you test so you can spot patterns and know whether a slow day is normal variation or a sign something is wrong.
- Compare your results to what your internet provider promised you in your contract, not to what other people get, because speeds vary by location and plan.
How to run a speed test on your own device
The easiest way is to visit Speedtest.net or Fast.com in a web browser on the device you want to test. Both are free and require no account. Speedtest.net is run by Ookla, a company that has been measuring internet speed for years. Fast.com is run by Netflix. Both work the same way: you click a button, wait 30 to 60 seconds while the test runs, and see your read speed, upload speed, and ping displayed on the screen.
For the most honest result, use an ethernet cable plugged directly into your router if your device has an ethernet port. WiFi speed is almost always slower than what the cable can do, partly because WiFi has to share the airwaves with other devices and networks. If you only use WiFi at home, test over WiFi — that number is more useful to you than a cable number would be. Just make sure you are close to the router, in the same room if possible, so WiFi signal strength is not the limiting factor.
Before you test, close web browsers, email programs, video apps, and anything else that uses the internet. Pause any downloads, backups, or updates. If someone else in your house is streaming video or downloading files, ask them to pause for five minutes. Background activity will use up some of your speed and make your test results lower than your actual available speed.
Why your speed changes throughout the day
Internet speed is not constant. Your provider's network has limited capacity, and when many people in your area use the internet at the same time, that capacity gets divided among them. Early morning usually shows faster speeds because fewer people are online. Evenings, especially between 7 and 11 p.m., are typically slower because that is when most people stream video, work from home, or use social media.
Weather can also affect speed, especially if your internet comes through a cable line or wireless connection. Heavy rain or snow sometimes degrades the signal. If you test once and get a slow result, test again at a different time before you call your provider to complain. A single slow test might just be a busy time on the network, not a problem with your service.
Understanding what your numbers mean
Your internet plan probably promises a certain speed — often something like "up to 100 Mbps" or "up to 500 Mbps". The word "up to" is important. Your provider is not promising you will always get that speed. They are promising that is the maximum your plan can deliver under ideal conditions. Your actual speed will usually be lower, and that is normal.
Check your bill or your provider's website to find what speed tier you are paying for. Then compare your test results to that number. If you consistently get 80 to 90 percent of the promised speed, your service is working as intended. If you regularly get less than 50 percent of the promised speed, and you have already closed background programs and tested at different times, that is worth reporting to your provider.
Do not compare your speed to what your neighbor or friend gets. Their speed depends on their location, their provider, their plan, and what is happening on their network at that moment. The only useful comparison is your speed against what you are paying for.
Keeping track of your results over time
Write down your speed test results — the date, time of day, read speed, upload speed, and ping — each time you test. After a few weeks, you will see patterns. You might notice that your speed is always slower on weekday evenings, which is normal. You might notice it is slower on rainy days, which is also normal for some connection types. You might notice it dropped suddenly and stays low, which could mean a problem worth investigating.
If you see a sudden drop that does not recover, restart your router by unplugging it for 30 seconds and plugging it back in. If the speed is still low after a restart, test again the next morning. If it is still below 50 percent of your promised speed, contact your provider and tell them your test results. Having written records makes that conversation much easier.
Speed tests on mobile phones and tablets
You can run a speed test on a phone or tablet the same way — visit Speedtest.net or Fast.com in a web browser. Mobile speed will usually be lower than home WiFi speed, partly because mobile networks have to serve many devices across a wide area. If you are testing your home WiFi on a phone, move close to the router for the most accurate result.
Mobile data speed (using your phone's cellular connection, not WiFi) depends on your phone plan and how strong the signal is in your location. Testing mobile data speed is useful if you want to know whether your phone plan is delivering what you are paying for, but it will not tell you anything about your home internet.
What to do if your speed is much slower than expected
First, restart your router. Unplug it, wait 30 seconds, and plug it back in. This clears out temporary problems and often restores speed. Then test again after the router has fully restarted, which usually takes two to three minutes.
Second, check how many devices are connected to your WiFi. Open your router's settings (usually by typing 192.168.1.1 into a web browser, though this varies by router model) and look for a list of connected devices. If you see devices you do not recognize, someone else may be using your WiFi. If you see a lot of devices, that could be why your speed is slow — the WiFi is divided among them.
Third, test again at a different time of day. If the speed is normal in the morning but slow in the evening, the problem is network congestion, not your service. If the speed is consistently low no matter what time you test, contact your provider. Have your test results ready and tell them the speed you are getting versus the speed you are paying for.
Frequently Asked Questions
Does it matter which speed test website I use?
Speedtest.net and Fast.com are both reliable and will give you similar results. Speedtest.net shows more detail, including ping and which server it tested against. Fast.com is simpler and faster to run. Pick whichever you prefer — the important thing is testing the same way each time so you can compare your results to yourself over time.
Why is my WiFi speed so much slower than my ethernet speed?
WiFi travels through the air and has to share space with other networks and devices. Ethernet is a direct cable connection with no interference. If you are far from the router, the difference will be even bigger. This is normal. If your WiFi speed is still fast enough for what you do, there is no problem. If it is too slow, move closer to the router or ask your provider about a WiFi extender.
Can I trust the speed my provider's own speed test shows?
Providers sometimes run their own speed tests on their websites. These can be less reliable than independent tests like Speedtest.net because they are measured on the provider's own network, which may not show real-world conditions. Use an independent speed test for the most honest picture of your actual speed.
What ping number is good?
Ping under 50 milliseconds is good for most activities. Under 20 milliseconds is excellent. For video calls and web browsing, anything under 100 milliseconds feels responsive. For online gaming, players usually want under 50 milliseconds. If your ping is consistently over 100 milliseconds, you might notice lag in video calls or games.
Should I test my speed every day?
No. Testing once a week or once a month is enough to spot patterns. Testing every day will just show you normal variation and waste your time. Test when you first set up service, then monthly or whenever you notice your internet feels slow.