Diagnose before you fix
Slow internet has three broad possible causes: the line coming into your home, the router and wireless network, or the device you are using. Random fixes tend to waste time because you never learn which of the three is at fault. The path below narrows it down in order, with the cheapest checks first.
Step 1: Describe the problem precisely
Before touching anything, note what “slow” means. Is it all devices or one? All rooms or one? All day or at certain times? All sites or one service? Pages loading slowly, video buffering and calls stuttering point to different things. A slowdown in the evening for every device hints at congestion or the line. One laptop alone being slow points to that laptop.
Step 2: Restart in the right order
Restarting clears temporary faults and is worth doing properly.
- Turn off the router and modem (or combined unit). If they are separate, unplug both.
- Wait about 30 seconds.
- Power on the modem first and wait until its lights settle, which can take a few minutes.
- Then power on the router and wait again.
- Restart the affected device too.
Do not keep repeating this. If a restart helps for a day and the problem returns, something else is going on, and the information is useful.
Step 3: Check one device against another
Try a second device in the same spot. If a phone is fast and a laptop is slow, the laptop is the likelier cause: an old network adapter, a background update, a browser with many tabs, or a full drive. Close heavy apps, check for software updates, and restart it. If every device is slow, keep going.
Step 4: Test by cable
This is the most useful step. Connect a computer directly to the router with an ethernet cable and run a speed test. Then run it again on Wi-Fi in the same room.
- Fast on cable, slow on Wi-Fi: the problem is probably wireless. Go to step 5.
- Slow on both: the problem is probably the line, the modem, or the router itself. Go to step 6.
Note the results with the time. A single test can be misleading, so run two or three.
Step 5: If the wireless side is the issue
Work from the easiest fix toward larger ones.
- Get closer. Test next to the router. If it is fast there and slow far away, distance and walls are the issue. The basics are in the explanation of the home wifi signal.
- Check the router’s spot. A router in a cabinet or a far corner hurts. Moving it can help, as described under router placement.
- Try another band. If your phone offers both 2.4 and 5 GHz networks, try the 5 GHz one when close, and 2.4 GHz when far.
- Look for interference. Does the slowdown coincide with a microwave, a cordless phone or neighbors’ peak use? Changing the channel in the router settings sometimes helps in crowded buildings.
- Count the devices. Many devices streaming and syncing at once share a limited resource. Pause large downloads and cloud backups and see if the problem eases.
- Update firmware. Check the router for updates.
- Consider hardware. If a big house leaves dead spots, options include wifi extenders, mesh wifi, or cabling. Cabling some devices removes load from the air.
Step 6: If the line or router is the issue
When even a cable test is slow:
- Compare the result with your plan. Plans are usually described as “up to” a speed, so some shortfall is normal, but a result far below it, repeatedly, is worth noting.
- Check cables. A loose, kinked or damaged cable between the modem and the wall, or between the modem and router, can cause trouble. Reseat each connection.
- Connect the computer directly to the modem, if your setup allows it. If speed is good there but not through the router, the router is the suspect. Settings reset or a firmware update may help.
- Look at the modem or router status lights, and check the manual for what they mean. A light indicating no connection or a repeated reboot suggests a line fault.
- Check your provider’s outage page or app, from a phone on mobile data.
- Think about time of day. If speeds fall sharply every evening on a shared connection, that may reflect local congestion.
Step 7: Rule out other causes
- Malware or unwanted software on a computer can use bandwidth. A security scan is a reasonable check.
- Background uploads, such as photo backups, can eat upload capacity and slow everything.
- The service itself. If only one site or app is slow, the problem may be at their end.
- Old equipment. Routers and modems that are many years old may struggle with newer plans.
- Your plan. If you simply have more devices and users than before, a plan upgrade may be justified. The notes on internet speed plans help judge this.
When to contact the provider
Calling is sensible when the cable test is consistently far below your plan, when lights show a fault, or when the problem is clear but outside your control. You will get further if you can say: “I tested by cable directly to the router at these times and got these results, and I have restarted the equipment.” That one sentence saves you a lot of scripted troubleshooting.
Keep a short log
Write down the date, time, wired and wireless results, and what you changed. Patterns often appear within a week, and a log turns a vague complaint into evidence. It also protects you from fixing the same thing twice.