There's a specific kind of frustration that comes from Wi-Fi that works. Pages load, just slowly. Video buffers at 720p. Video calls drop every few minutes. You run a speed test and get a number that looks fine, then open a second tab and everything stalls again.

The problem usually isn't your internet. It's the radio link between your laptop and the router — and Windows will tell you exactly what's wrong with it if you ask.

The command is netsh wlan show interfaces. It's built in, takes one second, and shows you numbers that no speed test will ever give you.

The command

Open Command Prompt (normal, no admin needed) and run:

text

netsh wlan show interfaces

You'll get a short block of output for each wireless adapter. On most laptops there's just one. Here's what mine looked like on a bad day:

text

Name                   : Wi-Fi
Description            : Intel(R) Wi-Fi 6 AX201 160MHz
State                  : connected
SSID                   : HomeNetwork
BSSID                  : 3c:37:86:aa:bb:cc
Network type           : Infrastructure
Radio type             : 802.11ac
Authentication         : WPA2-Personal
Cipher                 : CCMP
Connection mode        : Auto Connect
Channel                : 6
Receive rate (Mbps)    : 144
Transmit rate (Mbps)   : 144
Signal                 : 48%

Six of those lines matter. The rest you can ignore.

What actually matters

Signal — this is the one people miss. It's a percentage, and it's not linear. Anything above 70% is good. 50–70% is workable but lossy. Below 50%, you're losing packets constantly and no amount of "restart the router" will fix it. 48% is why my video calls were dropping.

Channel — the frequency slot you're using. On 2.4 GHz, channels 1, 6, and 11 are the only ones that don't overlap, and everyone's router defaults to one of them. If your neighbors are all on channel 6, you're all fighting for the same airtime. This is the single most common cause of "my Wi-Fi is slow but my speed test says it's fine."

Radio type — 802.11n is old. 802.11ac is normal. 802.11ax is Wi-Fi 6. If you're paying for a fast connection and this says 802.11n, your laptop is the bottleneck, not your router.

Receive / Transmit rate — the negotiated link speed. This is not your internet speed. It's the maximum the radio link can carry. If it says 144 Mbps, that's your ceiling regardless of what plan you're paying for. When this number fluctuates wildly, your signal is unstable.

BSSID — the MAC address of the access point you're connected to. Useful if you have a mesh system and want to know which node you're actually on. If you're getting bad signal, you might be stuck on the far node instead of the near one.

SSID — the network name. Sounds obvious, but if you have a 2.4 GHz and a 5 GHz network with similar names, this tells you which one you're actually on.

The 2.4 vs 5 GHz trap

Most routers broadcast two networks. 5 GHz is faster and less crowded but has shorter range. 2.4 GHz is slower and much more crowded but reaches further.

Windows often connects you to whichever it saw last, not whichever is better. If your Radio type shows 802.11n and your Channel is 1, 6, or 11, you're on 2.4 GHz — possibly while sitting ten feet from a perfectly good 5 GHz network.

The fix is to forget the 2.4 GHz network on your laptop and connect only to the 5 GHz one, if you're close enough to the router for it to work. If you're far away, the opposite is true and 2.4 GHz is the right choice.

Finding a clear channel

Windows won't tell you which channels your neighbors are using — but it will show you every network in range, which is close enough:

text

netsh wlan show networks mode=bssid

That lists every visible network with its channel and signal strength. Count how many are on your channel. If you're on channel 6 and see four other networks also on 6, that's your problem — log into your router and change the channel to something empty, or move to 5 GHz entirely.

On 5 GHz, channel congestion is much less of an issue because there are far more non-overlapping channels available, but it's still worth checking if you're in a dense apartment building.

A real diagnostic sequence

When someone tells me their Wi-Fi is slow, this is the order I check things:

  1. netsh wlan show interfaces — is the signal above 70%?
  2. Is the radio type 802.11ac or better?
  3. Is the channel crowded? (netsh wlan show networks mode=bssid)
  4. Are they on 2.4 GHz when 5 GHz is available?
  5. Only then do I look at the router or the ISP.

In my experience, steps 1 through 4 catch most "slow Wi-Fi" complaints before anyone needs to call their provider.

Honest limitations

  • Signal percentage is a rough estimate. Different drivers report it differently, and it's not a direct measure of throughput. Use it as a relative indicator, not an absolute number.
  • This only diagnoses the wireless link. If your signal is 90% and your speed is still bad, the problem is upstream — router, modem, or ISP. This command won't help with that.
  • It can't see interference from non-Wi-Fi sources. Microwave ovens, cordless phones, and baby monitors all sit on 2.4 GHz and won't appear in the network list. If your Wi-Fi dies every time someone uses the microwave, that's your answer.
  • The rates shown are negotiated link rates, not measured throughput. Real-world speed is usually 40–60% of what's shown, because of overhead.

Why I keep this one handy

Speed tests tell you whether your internet is fast. This command tells you whether your Wi-Fi is the reason it isn't. Those are different questions, and for most people with a slow connection, the second one is the actual answer.

Run it once when your Wi-Fi is good and once when it's bad. The difference between the two outputs will tell you more than any speed test ever will.