Symptoms
- Many Wi-Fi networks show up in a scan from your home
- Speed and reliability are worse than expected despite good router placement
- Wi-Fi is noticeably worse during evenings when more neighbors are online
- Problem is specific to apartments, condos, or dense housing
Likely causes
- CommonWi-Fi channel congestion from nearby networksThe 2.4GHz band has only a few non-overlapping channels, and crowded buildings often have dozens of networks competing for them.
- CommonRouter set to a fixed, congested channelMany routers default to channel 1, 6, or 11, which get crowded fast in apartment buildings.
- Possible5GHz band less crowded but shorter range5GHz has more available channels and less interference, but doesn't travel through walls as far.
What to do
- Use a Wi-Fi analyzer app on your phone to see which channels nearby networks are using.
- In the router's settings, switch the 2.4GHz channel to a less crowded one, or set it to 'auto' so the router picks periodically.
- Prefer the 5GHz band for devices near the router, since it has more channels and typically less neighbor interference.
- Set the channel width to 20MHz on 2.4GHz instead of 40MHz in crowded areas, which reduces interference even if it slightly lowers max speed.
- Reposition the router as centrally as possible within your own unit to maximize your relative signal strength over neighboring networks.
- If interference remains bad, consider a mesh system, since some models actively manage channel selection more effectively than basic routers.
- Check with your building or ISP whether a wired connection option (like Ethernet to a specific room) is available as an alternative to relying on congested Wi-Fi.
Tools and parts
- Wi-Fi analyzer app
When to call a pro
Not usually needed for this issue.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.