macOS Tahoe: Dock icon rendering bugs (pixelation, gray boxes)

Hi everyone,

After updating to macOS Tahoe 26 (25B78), I’ve encountered several Dock issues:

  • Dock icons appear pixelated (especially at small sizes).
  • Third-party app icons get placed inside gray boxes (“icon jail”), making them harder to recognize.
  • Custom folder or app icons are sometimes replaced with generic ones.
  • Icon and widget themes can mismatch when switching between light and dark mode.


Steps to reproduce:

  1. Update to macOS Tahoe 26.
  2. Add third-party apps or custom folders to Dock.
  3. Resize the Dock or use an external monitor.
  4. Activate/deactivate screensaver or switch display modes.
  5. Switch between appearance themes.


What I’ve tried:

  • Restarting the Dock via Terminal (killall Dock)
  • Restarting my laptop twice

Is anyone else seeing this? Any solid workarounds? Appreciate any help or insights!


MacBook Air 13″, macOS 26.1

Posted on Nov 6, 2025 8:58 PM

Reply
12 replies

Nov 11, 2025 4:51 PM in response to dialabrain

Thanks for checking. It may be size/session‑dependent.

On macOS 26.1 (25B78), I can reproduce at small Dock sizes.

Exact settings when it breaks (in my case): tilesize=24, magnification=1, largesize=26 (built‑in display on Default for display; also repro on an external).

I’ve attached two captures taken minutes apart — Bad shows pixelation/aliasing, Good is crisp.

If you try the exact values below and still don’t see it, it may be model‑specific or session‑specific.



defaults write com.apple.dock tilesize -int 24
defaults write com.apple.dock magnification -bool true
defaults write com.apple.dock largesize -int 26
killall Dock


Current reads here:


tilesize=24
magnification=1
largesize=26

Nov 11, 2025 4:23 PM in response to hnrie

Same here on macOS 26.1.


Dock icons look pixelated/aliased at small sizes and sometimes “fix” themselves after a few reboots, then come back.


Setup: built‑in display set to Default for display; also reproducible on an external monitor.


tilesize=24, magnification=1 (On), largesize=26.


Tried: reset Dock prefs (defaults delete com.apple.dock; killall Dock), IconServices/cache clears, toggling Reduce Transparency/Motion. Safe Mode didn’t change it.


Looks like a 26.1 rendering/scale regression at small sizes.

Nov 11, 2025 5:15 PM in response to dialabrain

Fair point about the slider. I only quoted exact values because the glitch seems to live in a narrow size band.

On 26.1 I can repro at the small end. If you nudge the slider to roughly 10-15% from the left (and optionally a tiny magnification), you may see the same aliasing. I’m not saying “people should use 24 px”; it’s just that the bug only shows in that tight range, so exact numbers make it reproducible.

macOS Tahoe: Dock icon rendering bugs (pixelation, gray boxes)

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