How to check internet speed and connection problems
How to check internet speed and connection problems should start with a measurement, not with a phone call to your provider. A browser bar and a support ticket tell you very little, because slow can mean a crowded wireless channel, a wrong DNS server, packet loss on a single hop, or a router that has been running for six years. Ping tells you about latency and loss, nslookup tells you whether names resolve, tracert tells you where the path breaks, and a speed test tells you what you can pull down. Work through them in that order and you will know whether to blame the line, the router, or the device in your hand.
Start with the network flyout
Right-click the network icon in the system tray and Windows opens the network flyout. The bars next to the Wi-Fi name come from the adapter itself, so they show signal strength and nothing else. Four bars can still sit behind a crowded channel, and one bar can still deliver a full speed line close to the router.
The text under the Wi-Fi name is the more useful part. "Connected, secured" means the link is up and encrypted, "Connected, not secured" means an open network, and "No internet access" means the adapter has an address but cannot reach anything.
Ping: check internet speed, latency, and packet loss
Open Command Prompt and ping a public target. Two are useful: 8.8.8.8 is a Google DNS server with no name to look up, and google.com adds a lookup to the test.
ping 8.8.8.8
ping google.com
ping -t 8.8.8.8The third form runs until you press Ctrl+C, which catches a fault that comes and goes. Each reply prints a round trip time in milliseconds: under 30 ms is comfortable for calls and games, 30 to 80 ms is usable, and above 100 ms feels laggy. I treat anything over 100 ms as a problem.
Timeouts matter more than the average. Two misses in every hundred requests is 2 percent packet loss, and calls break up badly at that level even when the speed test looks perfect. If 8.8.8.8 replies fast while google.com does not, the delay is in name resolution, not on the route.
DNS problems versus bandwidth problems
nslookup asks a DNS server to turn a name into an address, so it tells you whether name resolution works at all.
nslookup google.com
nslookup google.com 1.1.1.1The second form queries a specific resolver, which separates a bad local setting from a broken provider. A healthy answer prints a "Name" line and an "Address" line. "can't resolve" or "No answer" means the lookup failed while the connection itself may be fine.
Three commands clear out cached and stale settings:
ipconfig /flushdns
ipconfig /release
ipconfig /renewThe first empties the DNS resolver cache, which fixes a name that still resolves to an old address. The last two drop your DHCP lease and ask for a new one, so the computer gets a fresh address from the router. The connection drops for a few seconds, and it is worth trying after a network change or a new router.
tracert shows where the path breaks
Where ping tells you the delay, tracert tells you the path.
tracert google.comEach line is one hop and the times are cumulative. Asterisks in the first few hops are normal, because many routers ignore the timed probes this test relies on. Look for the hop where the times jump sharply, or a hop that times out while later hops answer. That point is usually the first piece of equipment past your own network, and the hop number is what to quote on a support ticket.
What the internet speed test numbers mean
This is what each field is actually telling you.
| Number | What it means | What to look for |
|---|---|---|
| Download in Mbps | The ceiling for pulling data in | Streaming and page loads |
| Upload in Mbps | The ceiling for sending data out | Video calls and cloud backup |
| Latency in ms | Round trip delay | Under 30 ms suits calls |
| Jitter in ms | How much that delay varies | High jitter ruins calls |
| Packet loss in % | Probes that never came back | Above 2 percent breaks calls |
The megabit to megabyte conversion catches people out. A 100 Mbps line downloads at roughly 12 MB per second, not 100, so the two numbers differ by design.
Free tools: Speedtest.net, speed.cloudflare.com, and PowerShell
Speedtest.net is the most familiar, and Cloudflare runs a test at speed.cloudflare.com that many people find quicker because it picks a nearby server. Recent Windows 11 builds also include a network speed test inside Settings > Network & internet.
Windows can also report what the adapter sees:
Get-NetAdapter | Format-Table Name, Status, LinkSpeed, MacAddressRun that in PowerShell. Status should read Up, and LinkSpeed shows the negotiated speed, so a wireless adapter stuck on 433 Mbps while the line is gigabit already shows where the problem sits. Test three times: once with the household idle, once on Ethernet, and once at the time of day the trouble shows up.
Weak Wi-Fi signal strength and the two bands
The signal bars in the flyout are worth reading closely. A weak signal usually means distance, walls, or a router tucked behind a television, and in my experience it is the most common cause of a home connection that feels slow on one device.
Modern routers broadcast on two bands, and the choice trades speed against range. The 5 GHz band is faster and cleaner, but its signal does not travel as far. The 2.4 GHz band reaches further and passes through walls better, which suits a room at the end of the house, but it is slower and far more crowded, with only three non-overlapping channels shared by every router in the neighbourhood.
A laptop that struggles in the back room may be fine on 5 GHz in the lounge and poor on 2.4 GHz in the kitchen. Moving the router to a central, higher spot does more than any setting inside it.
One device slow, everything else fine
When the rest of the house is fine, the line is fine, and I look at the device first:
- Background work. Cloud sync, a game launcher, and Windows Update quietly use the whole line. Task Manager shows which app is sending data.
- A VPN or proxy. Both add a hop and often cap throughput, so test once with the VPN disconnected.
- The metered connection setting. In Settings > Network & internet > Wi-Fi, a metered connection stops background downloads and caps updates.
- A stale network adapter driver. The download, rollback, and clean install rules are the same as for graphics drivers, and how to update graphics drivers safely covers the method.
If the adapter itself is misbehaving, reset the Windows network stack from an administrator Command Prompt and restart:
netsh winsock reset
netsh int ip resetThat rebuilds the Winsock catalogue, which some antivirus tools damage when they filter traffic. It is safe, and the connection returns in about a minute.
If the machine feels slow for reasons unrelated to the network, check how to check which apps use the most RAM, because paging to disk makes every application feel slow. A USB Wi-Fi dongle can also be the weak link, and how to fix a USB drive that is not showing up covers that side.
Why the test is below the advertised speed
| Cause | What it looks like |
|---|---|
| Wi-Fi overhead | A wireless link delivers roughly half to two thirds of its rated speed |
| An old router | 802.11n or early 802.11ac hardware caps the whole network |
| A range extender | A single-band repeater halves throughput as it rebroadcasts |
| Distance and walls | The far end of the house falls back to 2.4 GHz |
| Peak hour congestion | Fine at midday, slow at 8 pm when your area is busy |
| A VPN or busy test server | Your traffic goes through a proxy, or the server is crowded |
Router checks: restart, firmware, and cables
Before blaming the provider, I restart the hardware properly. Unplug the modem, wait 30 seconds, plug it back in, and let it finish syncing before you power the router. Routers hold onto a bad state for hours, and a full power cycle clears it.
Then check for firmware updates in the router's admin page, usually at 192.168.0.1 or 192.168.1.1 in your browser. Firmware fixes wireless stability and speed faults that no amount of driver updating will touch. A loose or damaged Ethernet cable between the modem and the router causes the same dropouts people blame on the provider.
Plug a laptop into the router with an Ethernet cable and run the speed test again. That single test separates the wireless side from the line itself, and it tells you whether to call the provider or move the router.
Ethernet versus Wi-Fi
| Ethernet | Wi-Fi | |
|---|---|---|
| Latency | Low and steady | Varies with distance and channel traffic |
| Stability | No dropouts under load | Can stall when the channel is busy |
| Realistic speed | Close to the line speed | Usually well below it |
| Best use | A desktop or a room with a cable run | Laptops, tablets, and phones |
Symptom to cause table
| Symptom | Likely cause |
|---|---|
| Pages load but video buffers | Low bandwidth or a crowded channel |
| Everything works except calls | Packet loss or high jitter |
| Names fail but IP addresses work | A DNS problem |
| One device only is slow | Device software, a VPN, or background downloads |
| The test is slow on every device | The router, an extender, or the line |
| Fine in the morning, slow at night | Congestion at peak hours |
Frequently asked questions
Is 100 Mbps enough for a household?
For two people browsing, streaming in HD, and making video calls, 100 Mbps is comfortable. Several 4K streams at once, large game downloads, and a few simultaneous calls push you toward 300 Mbps or more. Upload speed matters more than most people expect, because every video call and cloud backup sends data out rather than pulling it in.
Why does my speed test give a different number every time?
Speed tests depend on which server you reach, the time of day, and whatever else the household is doing at that moment. Run the test three times and use the middle result rather than the best one, and test over Ethernet when you are diagnosing a problem. A result that swings by 30 percent between runs is normal.
Does a range extender slow down the internet?
Yes, on most models. A repeater receives the wireless signal and rebroadcasts it, so every frame crosses the air twice, which can halve your throughput. A mesh system with a wired backhaul avoids the problem. Putting a second router in extender mode and connecting it to the main router with an Ethernet cable keeps the full speed.
How do I tell a DNS problem from a connection problem?
Ping an address and a name. If ping 8.8.8.8 replies quickly while ping google.com does not, name resolution is the problem. Run nslookup google.com and then nslookup google.com 1.1.1.1 to see whether the default resolver is the one failing, and clear the cache with ipconfig /flushdns.
Should I restart my router to fix a slow connection?
Often yes, and it costs nothing. A full power cycle, modem first and router second, clears a stuck state that builds up over weeks of uptime. If the router needs rebooting every few days, the firmware is usually the reason, so check for an update on the manufacturer's support page.
What to remember
- Measure first. A speed test says what you have, ping and tracert say where the fault sits.
- Packet loss above 2 percent breaks calls even when the speed number looks fine.
- DNS problems and bandwidth problems look identical in the browser and need different tools.
- Weak Wi-Fi and a crowded 2.4 GHz channel explain most slow homes.
- One slow device means the device. Every slow device means the router or the line.
- Never download a driver from a third-party site, and that rule covers network adapters too.
Run ping 8.8.8.8 and tracert google.com from the affected device, then plug it into the router by cable and run a speed test. Those three results tell you whether you are looking at a provider problem, a router problem, or a problem on that one computer.