What actually slows your internet down

Internet speed depends on three separate things: the speed your provider sells you, the condition of the line between your house and their equipment, and what is happening inside your home right now. Most people focus on the first one and ignore the other two, which is why they think their internet is broken when it is just congested.

Your provider advertises a speed — say, 100 megabits per second. That is the maximum the line can carry under ideal conditions. You will not hit that maximum if your router is old, if you are far from it, if someone else in your house is downloading files, or if your device itself is slow. The line can also degrade over time: water damage, loose connections, or interference from power lines can cut your actual speed in half without changing what your provider is sending.

Before you call your provider or buy new equipment, test what you are actually getting. Go to speedtest.net on a device connected by ethernet cable directly to your modem — not WiFi. Run the test at different times of day. If you consistently get close to what you pay for, your line is fine and the problem is inside your house. If you get much less, the problem is between you and your provider.

Key Takeaways

  • Test your actual speed with an ethernet cable plugged directly into your modem at speedtest.net to separate line problems from home network problems.
  • If your speed is much lower than what you pay for, restart your modem by unplugging it for 30 seconds, then call your provider if the problem persists.
  • If your speed is close to what you pay for but WiFi is slow, move your router to a central location, away from microwaves and cordless phones, or switch to a 5 GHz network if your devices support it.
  • Devices far from the router or separated by many walls will always be slower — moving closer or using ethernet is faster than buying a new router.
  • If multiple people are using the internet at once, one person downloading or streaming video will slow everyone else down, and no equipment change will fix that.

Restart your modem and router

A modem that has been running for weeks or months can get stuck in a state where it is not communicating properly with your provider's equipment. Restarting it clears that state. Unplug the modem — the box your provider installed that connects the outside line to your home — and leave it unplugged for 30 seconds. Then plug it back in and wait three minutes for it to fully restart.

If you have a separate router (the device that broadcasts WiFi), unplug that too after the modem has restarted, wait 30 seconds, and plug it back in. Run your speed test again. If you are now getting the speed you pay for, the problem is solved. If not, move to the next step.

Check what is using your bandwidth right now

One person streaming video in 4K, downloading a large file, or playing an online game can use most or all of your internet. Everyone else in the house will notice the slowdown. Ask whether anyone is downloading, streaming, or video calling. If they are, that is why your internet feels slow — it is not actually broken.

If you want to know exactly what is using bandwidth, you can log into your router's settings. On most routers, go to 192.168.1.1 in a web browser, log in with the password on the back of the router, and look for a section called "Connected Devices" or "Bandwidth Usage". You will see what each device is doing. This tells you whether the problem is one person's activity or a network-wide issue.

Move your router to a better location

WiFi travels through air but is blocked or weakened by walls, metal, and water. A router in a closet, behind a TV, or in a corner of your house will not reach the rest of your home well. Move it to a central location — ideally in the middle of your house, elevated on a shelf rather than on the floor. The higher and more central it is, the better the signal reaches everywhere.

Keep the router away from microwaves, cordless phones, and baby monitors. These devices broadcast on the same 2.4 GHz frequency that WiFi uses and will interfere with it. If your router has a 5 GHz network option, use that instead — it is faster and less crowded, though it does not travel through walls as well. Devices far from the router will still be slower on 5 GHz, but devices close to it will be noticeably faster.

If moving the router does not help, the problem is not the router's location. Do not buy a new one yet.

Use an ethernet cable instead of WiFi

WiFi is convenient but slower and less stable than a wired connection. If you are testing speed or doing something that requires a fast, steady connection — uploading large files, video conferencing, online gaming — plug an ethernet cable directly from your router to your device. You will see an immediate speed increase and a more stable connection.

If you cannot run a cable to where you need it, a powerline adapter can help. This device plugs into an outlet near your modem, connects to the modem by ethernet, and broadcasts a WiFi signal from that location. It is not as fast as running a cable all the way, but it is faster than relying on WiFi from a distant router. Powerline adapters cost between $30 and $80.

Check whether your router is old

A router more than five or six years old may not support the faster WiFi standards that newer devices use. If your modem and line are fine, your location is good, and you are using 5 GHz, but WiFi is still slow on newer devices, the router itself may be the bottleneck.

Before replacing it, check what WiFi standard your router supports. Log into 192.168.1.1 and look for "WiFi Standard" or "802.11" in the settings. If it says only "802.11n" or older, upgrading to a router that supports "802.11ac" or "802.11ax" will improve speed on compatible devices. A mid-range router costs $60 to $150. Do not buy one unless you have ruled out every other cause first.

Contact your provider if the line itself is slow

If your ethernet-connected speed test shows you are getting much less than what you pay for — say you pay for 100 Mbps but consistently get 40 Mbps or less — the problem is between your house and your provider's equipment. Call your provider's support line and tell them your test results. They can run a test from their end and check whether the line has degraded.

Common causes are loose connections at the modem, water damage in the line, or interference from nearby power lines. Your provider can often fix these remotely or send a technician. If they cannot fix it and the line is genuinely damaged, they may offer to upgrade you to a faster service tier or switch you to a different type of connection if available in your area.

Frequently Asked Questions

Why is my WiFi slow when my ethernet speed is fast?

WiFi is slower than ethernet because it travels through air and is blocked by walls and interference. Move closer to the router, switch to the 5 GHz network if available, or use an ethernet cable for activities that need speed. If WiFi is much slower than it should be, restart the router and check whether someone else is using a lot of bandwidth.

Will a mesh WiFi system make my internet faster?

A mesh system extends WiFi to more rooms, but it does not increase your overall speed — it just spreads the same speed across a larger area. If your problem is that one room is far from the router, a mesh system helps. If your problem is that your line is slow or your router is old, a mesh system will not fix it.

How often should I restart my modem?

Restart it only when you notice your speed has dropped or your connection is unstable. You do not need to restart it regularly. If you find yourself restarting it more than once a month, call your provider — the modem may be failing.

Can I make my internet faster by changing my DNS?

Changing DNS can sometimes help if your provider's DNS is slow, but it rarely makes a noticeable difference. If you want to try it, use Cloudflare's DNS (1.1.1.1) or Google's (8.8.8.8). Change it in your router settings under DNS, not on individual devices. Test your speed before and after to see whether it actually helped.

What speed do I actually need?

For browsing and email, 10 Mbps is plenty. For streaming video, 25 Mbps per stream. For video conferencing, 2.5 Mbps upload and download. For online gaming, 5 Mbps is enough, but a stable connection matters more than raw speed. If multiple people are using the internet at once, add up what each person needs.