Why is my macbook air glitching and how can I fix it?

This does not sound like a simple “low storage” issue, especially since you still have around 80GB free. On an M1 MacBook Air, random screen flickering, app freezes, graphical glitches, lag, and unexpected restarts can come from either software instability or a hardware/display/logic board issue. The best approach is to separate software causes from hardware causes step by step.

First, make a full backup with Time Machine or another backup method before doing anything deeper. Unexpected restarts plus graphical glitches are not something I would ignore.

Since you already updated macOS, restarted, cleared storage, and tested Safe Mode, the next thing I would check is whether the issue also happens in Safe Mode. If the Mac is stable in Safe Mode, that usually points toward a third-party app, login item, browser extension, background utility, VPN, antivirus/cleaner app, menu-bar app, or driver-like software causing the problem. Go to System Settings > General > Login Items and remove anything unnecessary. Also temporarily uninstall system utilities such as cleaners, monitoring tools, VPN clients, third-party security apps, display tools, or window-management apps.

Next, check Activity Monitor when the lag starts. Look at CPU, Memory, and Energy. With 8GB RAM, an M1 Air can still perform well, but if many browser tabs, streaming apps, cloud sync apps, or Electron apps are open, memory pressure can spike and cause freezing. If Memory Pressure turns yellow/red or swap usage is very high, reduce startup apps, browser tabs, and extensions.

For the flickering and graphical glitches, test these points:

1. Does the flicker happen before login, on the lock screen, or in macOS Recovery?
2. Does it happen while using an external monitor?
3. Does the whole screen flicker, or only certain app windows?
4. Does it happen more when streaming video or using Safari/Chrome?

If the internal display flickers but an external monitor is fine, it could be the built-in display or display connection. If both internal and external screens glitch, it is more likely software, macOS graphics rendering, or a logic board/SoC-related issue.

Also check for crash reports. Open Console or look in Library/Logs/DiagnosticReports and check whether there are repeated “panic” or “WindowServer” crashes. If you are seeing kernel panic reports around the same time as the unexpected restarts, that is important evidence.

Run Disk Utility First Aid from macOS Recovery. Shut down the Mac, hold the power button until startup options appear, choose Options, then open Disk Utility and run First Aid on the internal disk/volumes. File system issues can sometimes cause freezes and strange behavior.

After that, run Apple Diagnostics. Shut down, start into startup options, then use the diagnostics option/key combination Apple provides for your Mac. If diagnostics reports an error code, save it and contact Apple Support or an Apple Authorized Service Provider.

If the issue continues after Safe Mode testing, removing login items, checking Activity Monitor, running First Aid, and running Apple Diagnostics, I would do a reinstall of macOS from Recovery without erasing the Mac. This keeps your data but refreshes the system files. If the same glitches continue even after a clean software reinstall, then hardware becomes much more likely.

In my experience, the biggest warning signs here are the graphical glitches plus unexpected restarts. Normal app freezing can be software or memory pressure, but screen flicker and rendering problems across random apps are more suspicious. If the problem appears in Safe Mode, Recovery, or immediately after a fresh macOS reinstall, I would stop troubleshooting and have the Mac inspected. It could be the display assembly, logic board, or another hardware-level problem.

So the order I would follow is:

Backup first.
Remove login/background apps.
Test Safe Mode carefully.
Check Activity Monitor memory pressure.
Test with an external display.
Run Disk Utility First Aid from Recovery.
Run Apple Diagnostics.
Reinstall macOS without erasing.
If still happening, get hardware service.

Do not waste time trying Intel-style SMC or NVRAM reset steps, because this is an Apple silicon Mac. For M1 models, a normal shutdown/restart is the relevant power-management reset step.