What actually slows down your PC's internet, and what you can fix

Your internet speed depends on three separate things: the speed your provider sends to your home, the speed your PC can receive, and what your PC does with that signal once it arrives. You cannot change what your provider sends. You can improve the second and third.

Most speed problems on a single PC come from one of four sources: too many programs running in the background, a wireless connection that is far from your router, browser cache and cookies piling up, or malware. Testing which one is your problem takes about ten minutes and costs nothing.

Before you start: run a speed test at speedtest.net or fast.com on the device that feels slow. Write down the number. Then run the same test on a different device on the same network — a phone or tablet. If both devices show the same slow speed, your problem is your internet connection itself, not your PC. If only your PC is slow, the fixes below will help.

Key Takeaways

  • Close programs running in the background — especially Chrome, Spotify, OneDrive, and Discord — because they use bandwidth even when you are not looking at them.
  • Move your PC closer to your router or switch to a wired Ethernet cable, because wireless signals weaken with distance and walls.
  • Clear your browser cache and cookies every month, because they accumulate and slow down page loading.
  • Run a malware scan with Windows Defender or Malwarebytes, because viruses and unwanted software consume bandwidth and processing power.
  • Restart your router by unplugging it for 30 seconds, because it can get overloaded and forget how to send data efficiently.

Close background programs that eat bandwidth

On Windows, open Task Manager by pressing Ctrl+Shift+Esc. Click the "Processes" tab. Look at the "Network" column — it shows which programs are using your internet right now. Programs that show anything other than 0 are slowing you down.

The usual culprits are Chrome (especially if you have many tabs open), Spotify or other music apps, OneDrive or Google Drive syncing files, Discord, Slack, and Windows Update. Close the ones you are not actively using. If a program keeps coming back, right-click it and select "End Task" to stop it completely.

On Mac, open Activity Monitor from Applications > Utilities. Click the "Network" tab. The "Sent Bytes" and "Recv'd Bytes" columns show which programs are using your connection. Close the ones you do not need right now.

Switch to a wired connection or move closer to your router

Wireless signals weaken as they travel through walls, floors, and distance. If your PC is in a bedroom and your router is in the living room, you are losing speed with every wall between them.

The fastest fix is to plug an Ethernet cable directly from your router into your PC. This gives you the full speed your provider sends. If you cannot run a cable, move your PC closer to the router — even moving from one room to the next can double your speed.

If you must use wireless, position your router in a central location, away from microwaves and cordless phones, which broadcast on the same frequency and cause interference. If your router has a 5GHz band, connect to that instead of 2.4GHz — it is faster over short distances, though it does not travel as far.

Clear your browser cache and cookies

Every website you visit stores small files on your PC called cache and cookies. Over months, these pile up and slow down your browser. Clearing them takes two minutes and often noticeably speeds up page loading.

In Chrome, press Ctrl+Shift+Delete (or Cmd+Shift+Delete on Mac). Select "All time" under "Time range". Check "Cookies and other site data" and "Cached images and files". Click "Clear data".

In Firefox, press Ctrl+Shift+Delete (or Cmd+Shift+Delete on Mac). Select "Everything" under "Time range to clear". Check "Cookies" and "Cache". Click "Clear Now".

In Edge, press Ctrl+Shift+Delete. Select "All time". Check "Cookies and other site data" and "Cached images and files". Click "Clear now".

Scan for malware and unwanted software

Viruses, spyware, and unwanted programs consume bandwidth and processing power without your knowledge. Windows Defender, which comes built into Windows, can find most of them.

On Windows, open Settings > Privacy & Security > Virus & threat protection. Click "Scan options". Select "Full scan" and click "Scan now". This takes 30 minutes to an hour but runs in the background. If Defender finds anything, it will remove it automatically.

If you want a second opinion, download Malwarebytes (the free version is sufficient). Install it, open it, and click "Scan". Let it finish, then restart your PC.

On Mac, malware is less common, but you can download Malwarebytes for Mac and run a scan the same way.

Restart your router and check for interference

Routers can get overloaded and forget how to send data efficiently. Unplugging it for 30 seconds and plugging it back in fixes this about half the time.

Unplug the power cable from the back of your router. Wait 30 seconds. Plug it back in. Wait two minutes for it to restart completely. Run a speed test again.

If you still see slow speeds, log into your router's settings. Most routers have a sticker on the back with a web address like 192.168.1.1 or 192.168.0.1. Open that address in your browser. Look for a "Restart" or "Reboot" button and click it. Some routers also let you change the wireless channel — if you live in an apartment, switching from channel 1 to channel 6 or 11 can reduce interference from neighbors' networks.

Update your network drivers

Your PC's network drivers are the software that controls how it talks to your router. Outdated drivers can slow down your connection.

On Windows, right-click the Start button and select "Device Manager". Expand "Network adapters". Right-click your network adapter (usually something like "Realtek" or "Intel") and select "Update driver". Choose "Search automatically for updated driver software". Windows will download and install any available updates.

On Mac, go to System Settings > General > Software Update. If updates are available, install them and restart.

Disable bandwidth-heavy Windows features

Windows has several built-in features that use your internet in the background. Turning them off can free up bandwidth.

Open Settings > System > Storage. Click "Advanced storage settings" > "Storage Sense". Turn on "Storage Sense" and set it to delete temporary files automatically.

Open Settings > Privacy & Security > General. Scroll down and turn off "Tailored experiences" and "Improve inking & typing".

Open Settings > System > Notifications. Turn off notifications for apps you do not need — each notification check uses a tiny amount of bandwidth, but they add up.

Frequently Asked Questions

Why is my internet fast on my phone but slow on my PC?

Your PC probably has more programs running in the background. Check Task Manager for programs using the Network column. Also, your phone may be closer to the router or using a 5GHz connection while your PC uses 2.4GHz. Try moving your PC closer or switching to a wired cable.

Does restarting my PC actually help with internet speed?

Yes, but only if programs are running in the background. A restart closes everything and clears temporary files. If you notice speed problems mid-day, restart your PC and run a speed test again. If the speed returns to normal, a background program was the problem.

How often should I clear my browser cache?

Once a month is usually enough. If you notice your browser getting slower, clear it sooner. You can also set your browser to clear cache automatically every time you close it — in Chrome, go to Settings > Privacy and security > Clear browsing data, then check "On exit".

Can a VPN slow down my internet?

Yes. A VPN encrypts your data, which takes processing power, and routes it through another server, which adds distance. If you use a VPN, try turning it off and running a speed test to see the difference. Some VPNs are faster than others — paid services are usually faster than free ones.

What is a good internet speed for my PC?

For browsing and email, 10 Mbps is fine. For video calls, aim for 25 Mbps. For streaming video, 50 Mbps is comfortable. For online gaming, 100 Mbps or higher reduces lag. Your speed test result should be close to what your provider promises — if it is much lower, contact them.