Mac Dock Icon Size and Spacing: What System Settings Won't Let You Change (And What Will)

macOS gives you exactly one control for dock icon size: a slider in System Settings → Desktop & Dock → Size. There's no spacing control at all in System Settings, and the size slider tops out at a fixed maximum Apple decided for you. If you want finer control — a specific pixel size, tighter or looser gaps between icons, or different sizing on different monitors — you need to either use a terminal command or switch to a dock replacement app.

What System Settings actually lets you control

Open System Settings → Desktop & Dock and you'll find:

• Size — a slider from small to large, with no numeric readout
• Magnification — an optional hover-zoom effect, with its own slider
• Position on screen — bottom, left, or right
• Automatically hide and show the Dock — toggle only, no delay control in the UI

That's the complete list. There's no spacing control, no way to set icon size to an exact value, no per-monitor sizing, and no way to control the magnification delay.

How to set an exact dock icon size using Terminal

If you want a specific icon size rather than the slider's approximate range, you can set it directly:

bash defaults write com.apple.dock tilesize -int 48 killall Dock

Replace 48 with any value between 16 and 128. The Dock restarts immediately. To reset to the default (which is 64 on most Macs):

bash defaults delete com.apple.dock tilesize killall Dock

This sets the size precisely, which the slider can't do. If you drag the slider after running this command, macOS overwrites your value — so you'd need to re-run it.

Can you control spacing between dock icons on macOS?

Not directly through System Settings. macOS calculates spacing automatically based on icon size and the number of items in your Dock. You cannot set a spacing value natively.

The workaround most people use is invisible spacers — blank dock items that act as gaps. You can add one like this:

bash defaults write com.apple.dock persistent-apps -array-add '{"tile-type"="spacer-tile";}' killall Dock

This adds a draggable blank space to your Dock. You can add multiple spacers and drag them between app groups to create visual separation. To remove one, just drag it out of the Dock the same way you'd remove an app icon.

Small-tile spacers (narrower gaps) can be added with:

bash defaults write com.apple.dock persistent-apps -array-add '{"tile-type"="small-spacer-tile";}' killall Dock

Spacers are the native solution — they work on any macOS version, no third-party software required. The limitation is that you're adding blank slots rather than controlling actual pixel spacing, so your options are coarse.

Why the macOS Dock only has one monitor — and one size

One of the bigger frustrations with the stock Dock is that it lives on one screen. Move to a different monitor and you're either moving your cursor all the way back, or waiting for the Dock to chase you. If you have different monitor sizes — a 27-inch external and a 14-inch MacBook screen, for example — the same icon size looks very different on each. macOS offers no way to set different sizes per display.

Where Dockish changes the picture

Dockish is a full dock replacement for macOS 14+ that ships with the size and spacing controls Apple left out. Icon size is set to a specific pixel value from 24px to 96px, and spacing between icons is independently adjustable. If you have multiple monitors, you can run an independent dock on each one with different configurations — different icon sizes, different apps, different positions — or mirror the same layout across all of them.

A few things Dockish handles that the system Dock doesn't:

• Per-monitor docks — a dock on every connected display simultaneously, not just the active one
• Exact icon size control — numeric, not a slider
• Adjustable spacing and magnification — including magnification delay
• iPhone-style folders — drag one app onto another to group them, with a 2×2 preview grid
• Themes — glass, dark, light, or a custom tint colour
• App name labels below icons
• Hover previews for open windows

It's a $6.99 one-time purchase with a 7-day free trial, so you can test the full feature set before buying. There's no subscription.

If you just want spacers and a slightly adjusted icon size, the Terminal commands above will get you there for free. But if the single-monitor limitation or the lack of spacing control is what's actually frustrating you, Dockish is worth the trial.

Does adjusting dock icon size affect app icon quality?

No. macOS app icons are vector-based at their core, rendered at whatever size the Dock requests. Setting tilesize to 16 or 128 via Terminal won't make icons blurry — they'll scale cleanly in either direction. The practical lower limit is readability: below around 24–32px, icons become hard to distinguish at a glance.

What about magnification — is it worth turning on?

Dock magnification (the hover-zoom effect) is off by default. It's genuinely useful if you keep your icon size small to save space: icons zoom up when you hover, so you can keep the Dock compact without losing the ability to identify apps. Enable it at System Settings → Desktop & Dock → Magnification, then set the magnification slider to taste. There's no way to control the zoom speed or delay in System Settings. Dockish exposes both.

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Common questions

How do I make my Mac dock icons bigger or smaller?

Go to System Settings → Desktop & Dock → Size and drag the slider. For an exact pixel size, use the Terminal command defaults write com.apple.dock tilesize -int 64 (replace 64 with your preferred size, then run killall Dock). Values between 16 and 128 are accepted.

Can I add spacing between dock icons on Mac?

macOS has no direct spacing control, but you can add invisible spacer tiles using Terminal. Run defaults write com.apple.dock persistent-apps -array-add '{"tile-type"="spacer-tile";}' && killall Dock to add a blank draggable gap. Add multiple spacers to create grouped sections. Dock replacement apps like Dockish offer a proper spacing slider instead.

Can I have different dock icon sizes on different monitors?

No — macOS uses the same Dock, at the same size, regardless of which monitor it's currently sitting on. If you need per-monitor control, a dock replacement app is the only option. Dockish lets you run an independent dock on each display with individually configured icon sizes and layouts.