How to Fix Slow Internet: A Step-by-Step Checklist

Slow internet almost always has one specific cause, and the fastest way to fix it is to find that cause rather than trying random fixes in the hope that one sticks. This checklist works through the possibilities in order of how common they are and how little effort they take, so you narrow the problem down instead of guessing.

Work through it top to bottom and stop when your connection is behaving. Before you start, run a speed test and write the numbers down — download, upload and latency. Without a starting measurement you cannot tell whether anything you do actually helped.

Step 1: Decide which kind of "slow" you have

These three problems feel similar and have completely different fixes. Identifying yours saves an hour of wasted effort.

Step 2: Restart the modem and router properly

This genuinely fixes a large share of gradual slowdowns, because home routers accumulate memory pressure, stale routing state and overheating over months of uptime. Doing it properly matters:

1. Unplug the router and the modem from power (not just the reset switch).
2. Wait a full 60 seconds so the capacitors discharge and the provider clears the session.
3. Plug the modem in first and wait for its lights to settle — usually two to three minutes.
4. Then plug in the router and wait another two minutes before testing.

Re-test. If the numbers jumped back to normal, the fix worked — but if you are doing this more than every few months, the router is likely the underlying problem.

Step 3: Test wired to separate Wi-Fi from the line

This is the single most informative step in the whole checklist. Plug a laptop into the router with an Ethernet cable and run the speed test again.

• Wired is fast, Wi-Fi is slow — your line is fine and the problem is wireless. Go to Step 4.
• Wired is also slow — the problem is the router, the modem, the line, or the plan. Skip to Step 5.

If your device has no Ethernet port, the next best test is to stand right next to the router and re-test. A big improvement points the same way: Wi-Fi.

Step 4: Fix the Wi-Fi

In roughly this order of impact:

• Move the router. Central, elevated, out in the open. Not in a cupboard, not on the floor, not behind a television, not next to the microwave or a fish tank.
• Use the 5 GHz band for devices in the same room — it is dramatically faster than 2.4 GHz over short distances. Keep 2.4 GHz for devices further away or behind thick walls.
• Change the channel if you live in a flat or a dense street. Overlapping neighbours' networks are a common cause of a connection that is fast at 3am and slow at 8pm.
• Cover the dead zones with a mesh system or a wired access point rather than a cheap repeater, which halves throughput on the devices it serves.

Each of these is covered in detail in how to improve Wi-Fi speed at home.

Step 5: Find out what is using the bandwidth

Before blaming the connection, check that something in the house is not quietly consuming it. Common culprits:

• Cloud backup or photo sync running its first full upload.
• Game consoles downloading patches in the background — modern titles are 100 GB and up.
• Operating-system updates on several devices at once.
• A security camera or doorbell uploading continuous video, which eats upload bandwidth and makes everything else feel slow.
• Someone else on the network doing any of the above.

Most routers have a traffic or device list showing which client is using what. Pause the offender and re-test. If that was the cause, the long-term fix is scheduling those transfers overnight, or enabling QoS so bulk traffic yields to interactive traffic.

Step 6: Check latency under load

If the speed test result looks reasonable but the connection still feels bad, measure latency while the line is busy. Start a large download or upload, and while it runs, check your ping.

Step 7: Rule out the device and the router itself

• Test a second device. If only one laptop is slow, the connection is fine — look at that machine: background processes, a full disk, an old wireless card, an overzealous VPN or antivirus.
• Check for malware if one device is slow across every network it joins.
• Update the router firmware. Manufacturers ship real performance and stability fixes, and many routers do not update themselves.
• Consider the router's age. Hardware from the Wi-Fi 4 era cannot deliver a modern plan's speeds no matter how it is configured. If the wired result is fast and the wireless result caps out well below it, the router is the ceiling.
• Check who is on your network. An open or WEP-secured network can simply have uninvited users on it. Use WPA2 or WPA3 with a strong password.

Step 8: Compare the result with the plan you pay for

Find your plan's advertised speed on a recent bill, then compare it with a wired speed test. A wired result within roughly 80–90% of the advertised figure is normal and is not a fault. A wired result at half the advertised figure or less, repeatedly, at different times of day, is worth reporting.

It is also worth asking whether the plan is genuinely enough for the household — four people streaming and working at once need more headroom than the marketing suggests. What is a good internet speed? works through the arithmetic.

Step 9: Call the ISP with evidence

Support calls go far better when you arrive with data. Have ready:

• Several speed test results, taken wired, with dates and times of day.
• Your idle latency and your latency under load.
• Confirmation that you tested more than one device and restarted the equipment.
• The advertised speed of your plan.

Ask them to check the line for errors and signal levels rather than accepting a generic reset. If the equipment is theirs and it is several years old, ask specifically whether a newer model is available — it often is, at no cost.

What not to bother with

• Buying a faster plan to fix a Wi-Fi problem. If wired is already fast, more bandwidth changes nothing you can feel.
• "Internet booster" software. No application can create bandwidth that the line does not have.
• Cheap Wi-Fi extenders as a first resort. They typically halve throughput for connected devices; a wired access point or mesh node is the better answer.
• Changing DNS to fix throughput. A faster DNS resolver can make pages start loading slightly sooner, but it does not raise your speed.

In short

Once the connection is behaving, re-run the speed test and keep the result. The next time something feels wrong, you will have a baseline to compare against.

Read next

• 10 ways to improve your internet speed — the optimisation steps once nothing is actually broken.
• How to improve Wi-Fi speed at home — if Step 3 pointed at wireless.
• Why speed test results vary — how much variation is normal before you treat it as a fault.