DockDoor is a free, open-source Mac utility that surfaces live window previews when you hover over app icons in the Dock, bringing an Exposé-style glance to your everyday workflow without replacing any native macOS behaviour.
What is DockDoor?
DockDoor is a lightweight macOS accessibility utility that adds hoverable window thumbnails to the Dock. Park your cursor over any running app's icon and a polished popover appears showing every open window for that app — large enough to be useful, fast enough to feel instant. Click a thumbnail and you jump straight to that window. It is the feature macOS should have shipped years ago.
The project is MIT-licensed and lives on GitHub. Development is active, and the app integrates with macOS's own Accessibility APIs rather than any screen-capture hackery, which keeps the experience smooth and battery-friendly.
What does DockDoor do best?
DockDoor's single killer feature is its window-preview popover, and it executes that one thing with unusual polish. Thumbnails are rendered at a sensible size — not the postage-stamp miniatures you get from holding ⌘-Tab — and the hover delay is tunable so the popover appears exactly when you want it, not before.
- Live window thumbnails — see the actual current state of every window, not a stale icon or a blank rectangle.
- Click-to-focus — one click on a preview raises that specific window, bypassing the app switcher entirely.
- Multi-display aware — previews appear near the Dock regardless of which screen your Dock lives on.
- Keyboard-friendly — you can arrow-key through the thumbnails without lifting your hand to the mouse if you prefer.
- Customisable appearance — corner radius, preview scale, blur intensity, and hover delay are all dialled from a clean settings panel.
Where I felt the difference most was when juggling four or five Finder windows alongside a browser with a dozen tabs. Instead of cycling through ⌘-Tab or hunting in Mission Control, I hover the Finder icon, spot the folder I need instantly, and click. It shaves seconds off a task I was doing dozens of times a day.
Is DockDoor free?
Yes — DockDoor is completely free to download and use with no paywalled features, no subscription, and no nag screen. The project is open source under the MIT licence, so you can inspect every line of code before you install. A tip-jar or sponsorship link is available for those who want to support the developer, but nothing is locked behind it.
Who should use DockDoor?
DockDoor rewards anyone who keeps a lot of windows open simultaneously and relies on the Dock as their primary app switcher. If you live in the Dock — as opposed to Raycast or Alfred launchers — this utility plugs a genuine gap in macOS. Developers with multiple Terminal windows, designers flipping between Figma artboards, and writers with a half-dozen research documents all open will feel the benefit immediately.
It is less essential if you are already disciplined about window management with a tiling tool like Magnet or Moom, or if you do almost everything in full-screen spaces where the Dock is rarely visible. But for the large population of Mac users who just let windows accumulate, DockDoor brings calm.
What are the best DockDoor alternatives?
The closest native feature is Mission Control (three-finger swipe up or F3), which shows all windows but requires you to leave your current context entirely. HiDock adds Dock customisation including some preview behaviour, but it is a paid app with a broader scope. Witch by Many Tricks is a superb window switcher that complements DockDoor rather than replacing it — Witch shines in the ⌘-Tab flow while DockDoor shines in the Dock-hover flow. Overflow 3 goes further with application groups and palettes. None of them replicate the simple, hover-to-peek interaction that DockDoor owns.
How does DockDoor compare to HiDock?
HiDock reimagines the entire Dock experience — bigger icons, shelves, notification counts — and charges for the privilege. DockDoor does nothing to the Dock itself; it only adds the preview layer on hover, keeping a smaller footprint and a zero-cost licence. If you love your current Dock and just want the one missing feature, DockDoor is the surgical option. If you want a full Dock redesign, HiDock is worth evaluating — just know they can coexist since they target different parts of the interaction.
