Wi-Fi Channel Overlap Visualiser

Pick the right Wi-Fi channel: see which 2.4, 5 and 6 GHz channels overlap, score the neighbouring networks you enter, and get the clearest channel to set.

Quick answer

On 2.4 GHz only channels 1, 6 and 11 do not overlap each other, so those are the only channels worth choosing. On 5 GHz and 6 GHz a 20 MHz channel does not overlap its neighbour, but widening to 40 or 80 MHz does overlap more air — in a block of flats the wide channel is usually the slower one.

2.4 GHz: use 1, 6 or 115 GHz and 6 GHz: keep it at 20 MHz in a crowd
  1. Pick the band you want to fix. 2.4 GHz is the slow, crowded one; 5 GHz is where most devices should live.
  2. Add what your router can see. A Wi-Fi scanner app, or your router’s own list of nearby networks, gives you the channel and how strong each neighbour is.
  3. Read the answer, then set it. The tool names the channel to use and says what is sitting on it.

clear: nothing overlaps this channel light: a little interference busy: neighbours overlap it crowded: this is the worst choice

What to do with the answer
  1. Open your router’s admin page (usually 192.168.0.1 or 192.168.1.1 in a browser) and sign in.
  2. Find the wireless settings. In most TP-Link, NETGEAR and ASUS routers the channel dropdown sits under Advanced → Wireless or Wireless → General. Set it to the channel above and save. The router restarts its Wi-Fi, so every device reconnects.
  3. If you have a mesh system such as eero or Nest Wifi, there is no manual channel setting: those choose automatically. In that case work on placement instead (central, high, out of a cupboard), and use a second unit if one room still drops.

Two networks on the same channel take turns talking, so both get slower. This visualiser shows which Wi-Fi channels overlap, scores the air around you from the networks your router can see, and names the clearest channel to set.

How to use the visualiser

  1. Leave the band on 2.4 GHz and the width on 20 MHz to start.
  2. Open your router or a Wi-Fi scanner app, and read the channels your neighbours use.
  3. Add each one above, with the strength you see. A neighbour’s network on your channel is the only one that really costs you speed.
  4. Read the recommendation, then set that channel in your router’s Wi-Fi settings and save.
Thirteen 22 MHz channels spaced 5 MHz apart. Channels 1, 6 and 11 are shown in green because they do not touch each other; every other channel overlaps its neighbours and is shown in amber or red. 2.4 GHz: 22 MHz wide, only 5 MHz apart Green channels do not touch. Everything else sits on a neighbour and slows both networks. 1 no overlap 2 overlaps 3 overlaps 4 overlaps 5 overlaps 6 no overlap 7 overlaps 8 overlaps 9 overlaps 10 overlaps 11 no overlap 12 overlaps 13 overlaps 1 2 3 4 5 6 7 8 9 10 11 12 13 Use 1, 6 or 11. Never use 2, 3, 4, 5, 7, 8, 9, 10, 12 or 13: each one overlaps two or more others. afrozahmad.com
Channel overlap on 2.4 GHz. Diagram: afrozahmad.com

Why 2.4 GHz comes down to channels 1, 6 and 11

2.4 GHz channels are 22 MHz wide but spaced only 5 MHz apart, so neighbouring channels overlap heavily. Channel 1 covers roughly 2401-2423 MHz; channel 2 covers 2406-2428 MHz. Put a network on each and they interfere. Only 1, 6 and 11 sit far enough apart that three networks can share the band without touching.

That is why “my router picked channel 4, is that fine?” has a boring answer: no. Channel 4 overlaps channels 1 to 8. The tool above will never suggest it.

Channel overlap
two channels occupying the same frequencies, so devices on each must wait for the other.
Co-channel interference
two networks on exactly the same channel, the worst case: they share airtime directly.
Adjacent-channel interference
networks on nearby but not identical channels; less damaging than co-channel, still real.
Channel width
how much spectrum one channel uses. Wider carries more data when the air is clear and collapses faster when it is not.
PSC (6 GHz)
preferred scanning channels: the 6 GHz channels that client devices check first when joining.

5 GHz and 6 GHz: the width trade-off

On 5 GHz and 6 GHz, 20 MHz channels are spaced so they do not overlap. Widen to 80 MHz and one network occupies four of those channels, so it collides with more neighbours — which is why an 80 MHz channel often tests slower than a 20 MHz one in a busy building. Switch the band selector above and watch the bars grow as you widen the channel.

Practical rule: in a house with few neighbours, 80 MHz on 5 GHz gives the highest throughput. In an apartment block, 20 or 40 MHz on 5 GHz beats 80 MHz almost every time, because it stays clear of other people’s traffic.

Frequently Asked Questions

Is channel 1 better than channel 11?

They are equally good in principle — both are non-overlapping. The better one is whichever has fewer neighbours on it. That is the whole point of the tool: it tells you which of the three is clear right now, in your building, rather than applying a rule of thumb.

Should I use channel 13?

No, in the United States. The FCC band runs to channel 11; channels 12 and 13 are used in other regions, and some client devices will not join a network on them. The tool only recommends 1, 6 and 11 for that reason.

Does my router pick the best channel automatically?

Sometimes, and mostly on 5 GHz. Most consumer routers ship with “auto” channel selection, which often just stays on the channel it chose at first boot, even after neighbours arrive. Checking it yourself takes two minutes and is the single cheapest Wi-Fi improvement there is.

Why is my 5 GHz signal weaker than 2.4 GHz?

Higher frequencies are absorbed more by walls and floors, so 5 GHz reaches less far at the same power. That is a physics trade-off, not a fault: 2.4 GHz carries further, 5 GHz carries more data over a shorter distance. In an apartment, put devices that stay still on 5 GHz and accept that the far corner may prefer 2.4 GHz.

Sources and method

Every number in this tool comes from the channel plan itself, not from a vendor’s summary: 2.4 GHz channels are 22 MHz wide on a 5 MHz grid starting at 2412 MHz, 5 GHz channels are 20 MHz wide on a 5 MHz grid, and 6 GHz uses the same 20 MHz spacing with preferred scanning channels every fourth channel. Overlap is computed, not copied, so you can check any pair yourself in the chart.

  1. IEEE 802.11, the wireless LAN standard — channel spacing and widths used by the model.
  2. Wi-Fi Alliance, Wi-Fi CERTIFIED 6 — the dense-environment behaviour that makes overlap matter in a block of flats.
  3. FCC, radio frequency guidance — why the United States band stops at channel 11.
Channels, widths and overlap were checked against the standard on 1 October 2026. This is a model of the channel plan, not a survey of your building: for a real survey you need to read the networks your own equipment can see.
Cite this page
Afroz Ahmad, “Wi-Fi Channel Overlap Visualiser: Find the Clearest Channel”, afrozahmad.com, reviewed 1 October 2026.
https://afrozahmad.com/wifi-channel-overlap-visualiser/

About this page. Built by Afroz Ahmad, a CCIE with more than 20 years designing business, ISP and carrier networks, from the 802.11 channel plan. The tool runs entirely in your browser: nothing you type is sent anywhere.

Keep reading

Choosing a channel is one lever; the router is the other. Which 5 GHz channel to use, and when to change it explains the 5 GHz side in detail, the best routers for apartments covers hardware for flats where the airwaves are crowded, and TP-Link router lights helps when you cannot tell whether the router is even connected. If your router is the limit rather than the channel, the Spectrum router list and the DOCSIS 3.1 modem guide cover the hardware side.