Troubleshooting
Mac Graphics Glitches and Artifacts? Here's What's Going On
Seeing tearing, color blocks, or pink lines on your Mac? Diagnose graphics artifacts step by step — GPU drivers, color profiles, and corrupted caches.
Pink horizontal lines drift across your wallpaper. The Finder sidebar shows a checkerboard pattern. A YouTube video tears in three places when you scroll past it. These aren’t all the same problem — graphics glitches on a Mac can come from at least five different layers of the system, and the fix depends on which layer is misbehaving.
This guide will help you figure out where the glitch lives and what actually clears it.
What kind of artifact are you seeing?
Different artifacts point to different causes. Run through these:
- Pink, green, or purple lines or blocks: usually GPU memory corruption or a failing display cable. On Intel Macs, often the discrete GPU.
- Tearing during scroll or video: a vsync or refresh rate issue, almost always software-fixable.
- Frozen rectangles where windows used to be: window server glitch — a logout or restart fixes it.
- Whole-screen color shifts (everything turns blue or red): corrupted color profile or a stuck display panel transistor.
- Static-like noise across the whole display: cable bandwidth problem on an external display, or a panel-level fault on an internal one.
- Squares of garbage that move when you mouse over them: GPU driver or VRAM issue.
The first two are software in 90% of cases. The bottom three lean hardware. Lines and blocks are a coin flip.
Restart the WindowServer
Lots of glitches that look catastrophic are actually just the WindowServer (the macOS process responsible for drawing everything on screen) getting confused. You don’t need a full reboot to reset it.
Log out from the Apple menu and log back in. That’s it — the WindowServer restarts on logout, and any in-memory corruption it was carrying gets wiped. If the artifact is gone after login, it was a transient WindowServer glitch and you don’t need to chase it further unless it comes back.
If the artifact comes back within an hour or two, something is still feeding it bad data — keep reading.
Update macOS
Apple ships GPU driver updates inside macOS point releases. If you’re on macOS 14.4.1 and there’s a 14.7.2 sitting in System Settings → General → Software Update, install it. Several documented graphics regressions in early Sonoma builds were fixed in later 14.x releases, and similar patterns have shown up across macOS 15 Sequoia.
This is especially worth doing on:
- M1 and M2 MacBook Airs that show artifacts in Safari with hardware acceleration on.
- Intel iMacs from 2019–2020 with Radeon Pro Vega cards.
- Mac Studios with M1 Ultra (some early Sonoma releases had artifacts on external 6K displays).
Disable hardware acceleration in problem apps
When the artifact only shows up in one app — Chrome, Discord, Slack, Spotify — the app’s hardware acceleration is the suspect.
Chrome: chrome://settings/system → toggle off “Use graphics acceleration when available”. Restart Chrome.
Discord: User Settings → Advanced → toggle off “Hardware Acceleration”. Discord will quit and reopen.
Slack: Preferences → Advanced → toggle off “Toggle hardware acceleration”. Restart.
Spotify: Settings → Show Advanced Settings → toggle off “Enable hardware acceleration”.
If turning off acceleration in one app fixes that app’s artifacts, the problem is the GPU driver’s interaction with that app’s specific rendering path. Apple Silicon Macs handle acceleration differently than Intel + AMD setups, and apps that work great on one fall apart on the other.
Reset GPU-related caches
macOS keeps a stack of caches related to graphics — Metal shader caches, font caches, color profile caches, and the WindowServer’s own state. When one of these gets corrupted, you get artifacts that survive logouts and restarts.
Cache locations:
~/Library/Caches/com.apple.metal/— compiled Metal shaders~/Library/Caches/com.apple.CoreGraphics/— Core Graphics state~/Library/Preferences/ByHost/com.apple.windowserver.*— WindowServer per-display config/Library/Caches/com.apple.iconservices.store— icon rendering cache (yes, broken icons can produce display artifacts in Finder)
You can drag these to Trash manually, but you have to know the exact paths and you’ll need to restart afterward. Most users don’t want to do this with the Finder.
Test in safe mode
Safe mode boots macOS with most third-party kernel extensions and login items disabled, and it forces a graphics cache rebuild. If your artifacts disappear in safe mode, the cause is in user-level software or in the caches that safe mode rebuilds.
To enter safe mode:
- Apple Silicon: shut down, hold the power button until you see “Loading startup options,” select your disk while holding Shift, click “Continue in Safe Mode.”
- Intel: hold Shift while powering on. Release at the login window.
Look for the “Safe Boot” indicator in the menu bar (you may need to log in to see it). Use the Mac for a few minutes — open Safari, scroll, drag windows around. If it’s clean, restart normally and chances are the cache rebuild fixed it.
Color profile corruption
Wrong-looking colors that flicker or smear are often a profile issue, not a GPU issue. Open ColorSync Utility (Applications → Utilities → ColorSync Utility), click “Profiles,” and look at what’s installed.
Custom profiles from third-party calibration software (DisplayCAL, X-Rite i1Profiler, Datacolor SpyderX) sometimes get into a corrupted state and produce visual chaos. Switch back to the stock Apple profile for your display in System Settings → Displays → Color Profile and see if artifacts clear.
If the stock profile fixes it, the third-party profile is bad. Re-calibrate, or move the offending profile out of ~/Library/ColorSync/Profiles/ and /Library/ColorSync/Profiles/.
EDID issues with external monitors
If artifacts only show up on one external display, EDID — the data the monitor sends to tell the Mac what it can do — could be malformed.
Symptoms:
- Pink/green tinting only on one monitor.
- Banding visible on solid color backgrounds.
- HDR mode produces noise but SDR is clean.
Try a different cable type (HDMI to DisplayPort, or vice versa) — they read EDID differently. If you’re using a hub, plug the monitor directly into the Mac. As a last resort, BetterDisplay (free) can override a monitor’s EDID with a manually-built one, but that’s an advanced fix.
Apple Silicon vs. Intel: what’s different
The display driver path is fundamentally different between architectures, and that matters when you’re debugging.
Apple Silicon (M1, M2, M3, M4): single GPU integrated with the SoC. No graphics-switching glitches. Stricter about EDID. More likely to refuse to drive a marginal cable than to flicker through it. When something goes wrong, it’s usually a software/firmware issue, not a GPU swap glitch.
Intel + AMD: two GPUs (integrated Iris/UHD plus discrete Radeon Pro). Graphics switching is a known glitch source. The discrete GPU has its own VRAM and its own failure modes. Older Intel Macs (2018–2019) have well-documented dGPU issues that produce permanent artifacts.
If you’re on an Intel MacBook Pro and the artifacts are persistent, try forcing integrated graphics: System Settings → Battery → Options → Automatic graphics switching: Off. If artifacts vanish on integrated, the discrete GPU is degrading.
What Sweep does and doesn’t do
Sweep is a cleanup tool, not a diagnostic. What it does help with:
- Wiping the corrupted Metal shader, WindowServer, and CoreGraphics caches in one operation.
- Clearing leftover color profiles from uninstalled calibration tools.
- Removing broken icon and font caches that produce visual artifacts in Finder.
If a cache rebuild fixes your artifacts, Sweep is the fastest way to do that without poking around in ~/Library by hand. If your GPU is physically dying, no software tool will fix it — you’ll need a repair appointment.
There’s a faster waySweep does this cleanup in seconds. Try Sweep free →
Start with a logout, then update macOS. If those don’t help, disable hardware acceleration in suspect apps. If artifacts still survive, clean out the graphics caches. Persistent artifacts after all of that point to hardware — and you’ve ruled out enough software causes to know what to tell Apple support.