Why internet speeds differ across devices

Your laptop downloads a file quickly, but your phone crawls on the same Wi-Fi. Or two devices run a speed test minutes apart and show very different numbers. That does not automatically mean your internet plan or router is failing.

Devices can differ in Wi-Fi hardware, location, settings, and background activity. Use the Speed Test to compare them under the same conditions, then use the results to narrow down the cause.

Compare the devices fairly

1. Open the Speed Test on the first device and run a test. Note the download speed, upload speed, ping, and jitter.
2. Run the same test on the second device, in the same place and on the same Wi-Fi network. Keep the tests close together in time.
3. Pause downloads, video streams, cloud backups, and large updates on both devices. If someone else is using the connection, wait until they finish or test again later.
4. Repeat each test two or three times. A single result can be affected by temporary network traffic or a brief change in Wi-Fi conditions.

For a useful comparison, make sure both devices connect to the same router, not one to a guest network or mobile data. If possible, check which Wi-Fi band each device uses too. A router may offer 2.4 GHz, 5 GHz, or 6 GHz networks. The names can be separate, or the router can choose a band automatically.

What the results mean

The devices get similar results

If download, upload, and ping are close across repeated tests, the devices probably perform similarly on that connection. Small differences are normal. Speed test results change with network traffic, the test server, and the timing of each run.

One device is consistently much slower

A repeated gap points to something specific to that device or its connection. It may have older Wi-Fi hardware, a weaker antenna, a slower Wi-Fi band, a power-saving setting, or an app using the connection in the background. A device can also be farther from the router or blocked by a wall even if you think it is in the same room.

Both devices are slow at the same time

If both devices show a similar slowdown, the cause is more likely the router, your internet service, or congestion on the network. Run another test later. If the problem continues, compare the result with what you normally get and check whether other devices are transferring data.

Download speed is close, but ping or jitter differs

Download speed measures how quickly data arrives. Ping is the response time, and jitter is how much that time changes. A device may download quickly but still feel laggy in a video call or online game if its ping or jitter is higher. Wi-Fi interference and background traffic can affect these measures.

The result changes a lot between runs

Large swings can come from busy Wi-Fi, other people using the connection, or an unstable link. Wi-Fi bars do not measure speed or connection quality directly. For more on what the bars can and cannot tell you, see why Wi-Fi bars can't tell you your real speed.

How to fix a slow device

1. Move closer to the router. Test within a few feet of it, with a clear path between the device and router. If the result improves, distance or obstacles are likely affecting the Wi-Fi connection.
2. Check the Wi-Fi network and band. Confirm both devices are on the same network. On Windows 11, open Settings › Network & internet › Wi-Fi. On macOS, open System Settings › Wi-Fi. On an iPhone, open Settings › Wi-Fi. Android menu names vary, but start at Settings › Network & internet or Settings › Connections. If your router shows separate network names for its bands, compare devices on the same one.
3. Pause background transfers. Close cloud backup, file syncing, game downloads, and video streams, then repeat the test. On a computer, check whether an update or download is running before changing router settings.
4. Turn off a VPN temporarily. A VPN sends traffic through another server and can change speed and ping. If the test improves with it off, check the VPN app's server choice or settings. Turn it back on after the comparison if you need it for privacy or work.
5. Reconnect to Wi-Fi. Turn Wi-Fi off and on, then connect again. If the gap remains, restart the slow device and the router. A router restart briefly disconnects everyone, so wait for its connection lights to settle before testing again.
6. Check the device's Wi-Fi capability. Older phones and computers may support fewer Wi-Fi features or have less capable antennas than newer models. If the slow device is consistently behind even beside the router, test it on another network. A similarly slow result there suggests the device, rather than your home router, is the limit.

Why devices can differ on the same Wi-Fi

Wi-Fi standards and antennas vary between devices. One may support a newer standard or a wider channel, while another uses older hardware. The router and device also need to support the same features before they can use them. Band choice matters too: 2.4 GHz often reaches farther through walls, while 5 GHz and 6 GHz can provide more capacity nearby, but their signal may weaken more quickly with distance and obstacles.

Device software can affect the result as well. Power-saving modes may limit network activity, a browser or operating system may be busy, and security software or a VPN can add processing or routing time. The Speed Test measures the connection from that browser to its test server, so it is a comparison of real-world conditions, not a direct measurement of the speed entering your home.

The test exchanges data with TooLab's server to measure download and upload speed. If both devices remain slow compared with your usual results, this guide can help you check the next step: how to test internet that is slower than your plan.