When your MacBook Air M4 won't connect to WiFi, drops the connection frequently, or shows "No Internet Connection" despite being connected, here's how to fix it.
Toggle WiFi Off and On
Click the WiFi icon in the menu bar and toggle it off. Wait about ten seconds, then turn it back on. This simple action refreshes the wireless adapter and often clears temporary glitches that can happen, especially after waking from sleep.
Restart Your MacBook
Click the Apple menu > Restart. A full restart reloads the WiFi driver and clears any cached network states that might be causing trouble. I'd start with this one, as it resolves a surprising number of intermittent connection drops.
Forget and Rejoin the Network
Head to System Settings > WiFi. Click the information button (the small i) next to your network name and select Forget This Network. Confirm, then rejoin the network by selecting it from the list and entering the password again. This creates a brand new connection profile, which can fix authentication or configuration errors.
Renew Your DHCP Lease
In System Settings > WiFi, click Details next to your connected network. Go to the TCP/IP tab and click the Renew DHCP Lease button. This requests a fresh IP address from your router and is a solid fix for that "connected but no internet" situation.
Change Your DNS Servers
While still in the WiFi Details window, switch to the DNS tab. Remove any existing DNS servers listed there. Click the add button (+) and enter 8.8.8.8, then add another for 8.8.4.4 (Google DNS). You can also use 1.1.1.1 for Cloudflare's service. Slow or unresponsive DNS from your ISP can make websites fail to load, making it seem like the WiFi itself is broken.
Check for macOS Updates
Go to System Settings > General > Software Update. Apple regularly releases updates that include fixes for wireless connectivity bugs. Ensuring you're on the latest version of macOS is a crucial step, as I've seen updates specifically address WiFi stability on Apple Silicon Macs.
Delete Network Configuration Files
If problems persist, corrupted preference files might be the culprit. Open a Finder window, press Command + Shift + G, and type this path: /Library/Preferences/SystemConfiguration/. Look for and move these three files to your Trash: com.apple.network.identification.plist, com.apple.wifi.message-tracer.plist, and NetworkInterfaces.plist. Restart your MacBook Air afterward, and macOS will generate fresh, clean versions of these files.
Create a New Network Location
This is a more thorough reset. Go to System Settings > Network. Click the three-dot menu button next to the network service list and select Locations > Edit Locations. Click the plus (+) icon to add a new location, give it a name like "Fresh Start," and click Done. Finally, switch to this new location from the same menu. This action creates a completely new set of network preferences.
Run Wireless Diagnostics
Your Mac has a built-in tool for this. Hold down the Option key on your keyboard and click the WiFi icon in the menu bar. Select Open Wireless Diagnostics from the menu. Follow the on-screen assistant; it will scan your environment for interference and can generate a detailed report of your connection health.
Check Signal Strength and Channel
You can also check your connection details manually. Hold the Option key and click the WiFi icon. Look at the RSSI value; a number closer to zero is better. If you're seeing -70 dBm or lower, your signal is quite weak. Consider moving closer to your router. The menu also shows your channel, which can help identify congestion from neighboring networks.
Boot in Safe Mode
Safe Mode loads macOS with only essential drivers and can help determine if a third-party app is causing the issue. Shut down your MacBook Air M4. Press and hold the power button until you see the startup options window. Select your startup disk, then press and hold the Shift key and click Continue in Safe Mode. Test your WiFi in this state. If it works, something you've installed is likely interfering.
Reset the SMC and NVRAM
For Apple Silicon Macs like the M4, the System Management Controller (SMC) functions are handled by the chip itself. A full shutdown and restart often achieves the same effect. To reset parameter memory (NVRAM), shut down your Mac. Turn it on and immediately press and hold the power button for about 10 seconds, then release. This can clear settings related to ports and peripherals that may affect connectivity.
