What you're actually measuring when you test your speed

An internet speed test measures three things: how fast data downloads to your device, how fast it uploads from your device, and the delay (called ping) between your device and the test server. Download speed is what matters most for everyday tasks like streaming video or loading web pages. Upload speed matters if you video call, send large files, or stream from your computer. Ping measures lag — the time it takes for your device to "talk" to a distant server.

The numbers you see are measured in megabits per second, written as Mbps. One megabit is one million bits of data. Your internet plan probably promises a certain download speed — 100 Mbps, 300 Mbps, or something similar. A speed test tells you whether you're actually getting what you're paying for, or whether something is slowing you down.

Speed tests are not perfect. They measure your connection at one moment in time, to one server somewhere on the internet. Your speed changes throughout the day depending on how many people are using your network and how congested the internet is in your area. But a speed test gives you a real number to work with instead of guessing.

Key Takeaways

  • Run your speed test on a device connected by ethernet cable for the most accurate result, or on Wi-Fi if that's how you normally use the internet.
  • Close other programs and browser tabs before testing so nothing else is using your connection and skewing the results.
  • Speedtest.net and Fast.com are the two most widely used free speed test sites and give similar results.
  • Compare your results to your internet plan's promised speed — if you're getting 50 percent or less of what you pay for, contact your provider.
  • Run the test two or three times at different times of day to see whether your speed is consistently low or just slow at certain hours.

Running a speed test on your computer or phone

Open a web browser on the device you want to test — a laptop, desktop computer, or smartphone. Go to Speedtest.net or Fast.com. Both are free and require no account. Speedtest.net shows a large blue button that says "Go" — click it. Fast.com starts automatically when the page loads. The test takes about 30 seconds to a minute. You'll see the download speed appear first, then the upload speed, then the ping time.

The type of connection matters. If you're testing on Wi-Fi, you're measuring the speed your Wi-Fi router is giving you, not necessarily the speed your internet provider is sending to your house. If you want to know what your provider is actually delivering, connect your computer to the modem with an ethernet cable — the physical cable that plugs into your router or modem — and test again. You'll usually see a higher number because Wi-Fi is slower than a wired connection.

Most people use Wi-Fi most of the time, so testing on Wi-Fi tells you the speed you actually experience. But if you're troubleshooting a problem, test both ways. If your Wi-Fi speed is much lower than your ethernet speed, the problem is your Wi-Fi, not your internet provider.

Getting accurate results by preparing your device

Before you run the test, close everything else that uses the internet. Close browser tabs you're not using. Close email, video streaming apps, cloud backup software, and any program that might be downloading updates in the background. On a smartphone, close apps running in the background. If someone else in your house is streaming video or downloading files while you test, ask them to pause for a minute.

The reason is simple: if your device is using bandwidth for something else, the speed test can't use all of it, and you'll get a lower number that doesn't reflect your actual internet speed. You want the test to have your full connection to itself.

Restart your device before testing if you haven't done so in a few days. A restart clears out temporary files and stops background processes that might be running without you noticing. Then run the test immediately after restart, before you've opened other programs.

Understanding what your results mean

Your speed test shows three numbers. Download speed is the big one — this is what your internet plan promises and what you should compare to your bill. If your plan says 100 Mbps and you're getting 50 Mbps, something is wrong. If you're getting 90 to 100 Mbps, that's normal — you won't always hit exactly the promised speed.

Upload speed is usually much lower than download speed, and that's by design. Most internet plans promise 10 to 20 Mbps upload for a 100 Mbps download plan. Upload speed matters if you video call, upload photos to cloud storage, or stream from your computer. For most people, upload speed is fine as long as it's above 5 Mbps.

Ping is measured in milliseconds and shows how fast your device can communicate with a distant server. Lower is better. Anything under 50 milliseconds is good. Between 50 and 100 is acceptable. Above 100 and you might notice lag in video calls or online games. Ping is less important for everyday browsing and streaming.

Comparing your results to what you're paying for

Look at your internet bill or your provider's website to find the speed tier you're paying for. Comcast Xfinity, Verizon Fios, AT&T, Charter Spectrum, and other providers all list their speeds clearly. You might be paying for 100 Mbps, 300 Mbps, 500 Mbps, or another number.

Your speed test result should be close to that number — usually within 10 to 20 percent lower. So if you pay for 100 Mbps, getting 80 to 90 Mbps is normal. Getting 50 Mbps is not. If your results are consistently much lower than your plan promises, your provider may be throttling your connection, or there may be a problem with your equipment or line.

Write down your speed test results and the date. Run the test again in a week or two. If the speed is consistently low, contact your internet provider's customer support and tell them your speed test results. They may send a technician to check your modem and the line coming into your house.

Testing at different times to spot patterns

Internet speed varies throughout the day. During peak hours — usually between 7 p.m. and 11 p.m. — more people are using the internet in your area, and your speed may drop. Early morning and mid-afternoon are usually faster. Run your speed test at different times over a few days to see whether your speed is always low or only low at certain hours.

If your speed is fine in the morning but drops in the evening, the problem is likely network congestion in your area, not your equipment. If your speed is always low, the problem is more likely with your modem, router, or the line from your provider to your house.

Keep a simple log: write down the date, time, download speed, and upload speed each time you test. After a week, you'll see whether there's a pattern. This information is useful if you need to call your provider — they'll ask when the problem happens, and you'll have real data to show them.

Troubleshooting if your speed is lower than expected

If your speed test shows you're getting much less than your plan promises, start with the simplest fixes. Restart your modem by unplugging it for 30 seconds, then plugging it back in. Wait two minutes for it to fully restart. Then run the speed test again. A restart often fixes temporary slowdowns.

If you're on Wi-Fi, move closer to your router. Wi-Fi signal gets weaker the farther away you are, and walls and metal objects block it. If moving closer gives you a faster speed, your Wi-Fi range is the problem, not your internet provider. You might need a better router or a Wi-Fi extender.

If restarting the modem and moving closer to the router don't help, and your speed is consistently low on an ethernet cable connection, contact your internet provider. Tell them your speed test results and when the problem happens. They have tools to check the line coming into your house and can tell you whether the problem is on their end or yours.

Frequently Asked Questions

Why is my Wi-Fi speed so much slower than my ethernet speed?

Wi-Fi is slower than a wired connection because radio signals are weaker and more easily blocked than a physical cable. This is normal. If your Wi-Fi is extremely slow — less than half your ethernet speed — try moving closer to the router, restarting the router, or checking whether other Wi-Fi networks are interfering. If ethernet speed is normal but Wi-Fi is very slow, the problem is your router or Wi-Fi signal, not your internet provider.

Do I need to pay for a speed test?

No. Speedtest.net and Fast.com are both free and don't require an account. Your internet provider may also offer a speed test on their website, but the independent sites give you a more honest result because they're not run by your provider.

What speed do I actually need for streaming video?

Netflix recommends 5 Mbps for HD video and 25 Mbps for 4K. YouTube recommends 2.5 Mbps for HD. Most people find that 50 Mbps is comfortable for streaming, video calls, and browsing at the same time. If you live alone and only stream one thing at a time, 25 to 30 Mbps is usually enough.

Should I test on my phone or my computer?

Test on whichever device you use most often. If you mostly use your phone, test on your phone. If you mostly use a computer, test on a computer. The speed will be similar if you're on the same Wi-Fi network, but testing on the device you actually use tells you the speed you'll experience in real life.

How often should I run a speed test?

Once a month is enough for most people. If you're troubleshooting a problem, run it a few times over a week to see whether the slowness is consistent or happens only at certain times. After you've contacted your provider or fixed a problem, run one more test to confirm the speed has improved.