Intermittent or poor WiFi signal on the Raspberry Pi 4 or Pi 400 is usually caused by local conditions, router configuration, or outdated software. The steps below resolve the vast majority of connection issues.
💾 Update your Software
The first step is always to ensure you are running the latest drivers. In modern Raspberry Pi OS, updating the system automatically installs the latest WiFi firmware files, so you don't need to install them separately.
Open a Terminal window and run the following two commands to update the OS and the WiFi firmware:
sudo apt update
sudo apt full-upgrade
✓ Tip: If updates were installed, make sure to reboot your Raspberry Pi (sudo reboot) to apply the changes.
🌍 Set WLAN Country (Critical)
This is the most common reason for 5GHz WiFi failing to appear. Raspberry Pi OS often disables WiFi frequencies until it knows which country you are in, to ensure compliance with local radio laws.
Even if you selected your location during setup, it is worth resetting this manually:
✓ Step 1: Open a terminal and type sudo raspi-config
✓ Step 2: Select 5 Localisation Options
✓ Step 3: Select L4 WLAN Country and choose your location.
📡 2.4GHz vs 5GHz
The Raspberry Pi 4 supports both 2.4GHz (longer range, slower speed) and 5GHz (shorter range, high speed) bands.
If you are seeing connection drop-outs or poor reception, it might be because your router is trying to connect via 5GHz through a thick wall. Try forcing the connection to the 2.4GHz band to see if stability improves.
⚠️ HDMI Interference Warning: High-resolution displays (2560x1440 or 4K) combined with unshielded HDMI cables can emit radio noise that jams 2.4GHz WiFi. If your WiFi dies when your monitor is on, try using the 5GHz band or a high-quality shielded HDMI cable.
📶 Disable 'Smart Switching'
Many modern routers feature "Smart Switching" or "Band Steering," where they merge 2.4GHz and 5GHz into a single network name. This can confuse the Raspberry Pi, causing it to hop between bands and drop the connection.
✓ Recommendation: Log into your router settings and split your bands (e.g., name them "MyWiFi_2.4G" and "MyWiFi_5G"). Connecting the Pi specifically to one or the other often resolves instability.
🆔 Set a Static IP
Some "smart" routers struggle when multiple Raspberry Pis request IP addresses, occasionally causing conflicts where a device is kicked off the network.
📛 Change Hostnames
If you have multiple Raspberry Pis on your network, they default to the hostname raspberrypi. Having multiple devices with the same name can confuse your router.
✓ Recommendation: Use sudo raspi-config System Options Hostname to give each of your Pis a unique name (e.g., pi-kitchen, pi-arcade).