How Do Internet Speed Tests Work?

In today's hyper-connected world, a fast, reliable internet connection is critical. We rely on the quality and speed of our internet service for our daily activities, like working from home, attending online classes, playing video games, making video calls and powering a whole home of smart devices.

If your day-to-day activities are disrupted by a poor connection, what’s the first thing you do? Many of us turn to an internet speed test to see if our network is to blame. But what do internet speed tests actually tell you? And what can you do about speeds that are slower than what you’re paying for?

This comprehensive guide on internet speed tests will answer all of these questions and more. Plus, you’ll learn how these internet speed tests work, what they’re testing and why discrepancies in speed may occur. We’ll also show you what to do if your internet is slow and outline when it’s time to give your ISP a call.

● Packet Loss: measures how much of the downloaded and uploaded data failed to reach its destination, which can negatively impact your online activities and the performance of your devices.

What Units of Measurement Are Used During an Internet Speed Test?

After an internet speed test is complete, you’ll typically receive a report of your download and upload speeds, ping (or latency) and packet loss. The report will contain different units of measurement, and unless you know a lot about networking, these numbers may not mean much to you. Here’s a basic overview of the numbers and units of measurement you’ll see on an internet speed test.

● Megabits per second (Mbps) — a measurement of download & upload speeds.

Speed tests count how many megabits of data travel to your device (download speed) or from your device to a destination (upload speed) over the course of 1 second, on average.

For example, if you have 300 Mbps internet service, it wouldn’t be unexpected to see a download speed of 299 Mbps and an upload speed of 297 megabits per second.

🧑‍💻 EPB Tech Pros Tip: All EPB Fiber Optics internet has symmetrical download and upload speeds, but this isn’t always true for other providers. Some providers offer fast download speeds up to 1,000 Mbps with slow upload speeds that don’t even reach 50 Mbps.

As of 2024, ISPs are required to post details about your internet service in the form of “Broadband Consumer Labels” which look like the nutrition labels you see on the back of packaged foods. It’s a good idea to review these labels to make sure you’re getting upload speeds that are fast enough to meet your needs.

● Gigabits per second (Gbps) — a measurement of download & upload speeds. If your internet is faster than 1,000 Mbps, your results may be displayed in Gbps (or “Gigs”) rather than Mbps. This is because 1,000 Mbps equals 1 Gbps.

🧑‍💻 EPB Tech Pros Tip: These internet speeds usually mean the same thing: 1,000 Mbps = 1 Gbps = “1 Gig downloads and uploads.”

● Milliseconds (ms) — used when measuring ping or latency to indicate how many milliseconds it takes for data to travel to a server and back.

● Percentage, % or “Avg. %” — used to indicate what percentage of data packets never arrived at the destination during the speed test.

What Happens During an Internet Speed Test?

When you use a website or app to test and analyze your internet speed, you’ll typically see a progress bar of some kind that displays the following steps.

1. Establishing a Connection The test begins by connecting your device to a nearby test server. Some apps or websites will ask you to choose a nearby server on a map. It’s important to choose a nearby server. This reduces the data's travel time, which provides a more accurate measurement of your internet speed.
2. Transmitting Data The server then sends data packets from your device and requests data packets from the testing server. This two-way connection allows the test to measure download speeds, upload speeds and ping (or latency).
3. Analyzing Packet Loss Some tests will also check for packet loss—the percentage of data that fails to reach its destination—which can negatively impact the reliability and quality of your connection.

That’s why it’s crucial to select the closest possible testing server with the highest quality equipment. If the testing server is far away or is handling lots of traffic at once, you may see slower speed test results.

1. The Device You’re Using — Every device (phones, tablets, computers, gaming consoles, smart thermostats, etc.) has a maximum speed it can handle. This is because devices can have very different Wi-Fi or internet capabilities.

For example, if you’re testing your Wi-Fi speeds using an older smart TV, it’s possible that the TV can’t go faster than 450 Mbps, which means your internet speed test will display 450 Mbps instead of the maximum speed it’s capable of. Other factors include outdated firmware (check your settings to see if your device needs an update) or ethernet cable limitations (for example, Cat5e cables are slower than Cat6 cables).

1. ISP Throttling and Data Caps — Some ISPs intentionally slow down your network for a variety of reasons. For example, if you have data caps, you may experience slower speeds until the next payment cycle. Or, your ISP may slow down everyone’s connection during peak usage times to manage the bandwidth across their network.
2. Browser — Your internet speed test may yield different results based on which browser you’re using. Examples of popular browsers include Chrome, Firefox, Edge and Safari. If you’re getting test results that are lower than expected, try using Chrome or Edge.
3. Number of Connected Devices or Applications — Your internet speed test may be significantly impacted if you’re using your network for other apps and devices while you run the test. Playing online games, making video calls, streaming movies and downloading large files are all activities that consume considerable bandwidth and can reduce your speeds.

To get accurate speed test results, minimize your network usage by pausing downloads, stopping streaming services, and disconnecting unnecessary devices before performing the test. This ensures that the speed test reflects the true capacity of your internet connection without interference from other network activities.

The Impact of Wi-Fi and Device Capabilities

Wi-Fi is a convenient way to connect your devices to the internet. However, since Wi-Fi uses radio waves to transfer data, it has different speed limitations and variability compared to a wired connection. To learn more about how Wi-Fi works, check out this blog post.

If you’re getting a lower speed test result over Wi-Fi, here are some factors that could be affecting your results:

1. Interference: Other electronic devices, thick walls, and long distances from the router can disrupt Wi-Fi signals. Check out our blog post for help finding “The Best Place to Put Your Router for Strong Wi-Fi”.
2. Wi-Fi Band and Channel: Wi-Fi operates on different bands and channels, each with varying speeds and susceptibilities to interference. For instance, the 5 GHz band is faster but has a shorter range compared to 2.4 GHz.
3. Device Overload: Devices compete for bandwidth when they’re connected to a single Wi-Fi network. The more devices that are connected, the slower the speed for each device.
4. Outdated Router: Not all Wi-Fi routers can deliver Gig speeds. Check your router’s manual to learn about its speed limitations.

If you’re experiencing a weak Wi-Fi signal, check out our blog post on DIY ways you can fix it.

Internet speed tests are a vital tool for diagnosing and resolving issues with your internet connection. Understanding how these tests work and the factors that can affect your results empowers you to better manage your home network and hold your ISP accountable. Stay proactive in maintaining your network and keep communication open with your ISP to enjoy the best possible online experience.

Check your internet speed regularly, update your networking equipment when necessary, and stay informed about your ISP’s conditions and services. A proactive approach can help ensure that your internet connection remains fast, reliable, and consistent so you can power all your online activities at once without disruptions.

If you’re an EPB customer, our EPB Tech ProsSM are available to help you decode your internet speed test results, find ways to improve your internet connection and answer your questions anytime, day or night.

Visit epb.com and LiveChat with us or call 423-648-1372. Or, you can always order EPB Smart Net Plus to get the latest generation of warp-speed, whole-home Wi-Fi 6 technology for the fastest possible speeds on all your devices. Learn more about Smart Net Plus whole-home Wi-Fi.