See an app's windows from the Dock
Rest the pointer on an app in the macOS Dock and Koi shows its windows above it, minimized ones too. Click one to bring it forward. Pictured on your Mac only.
Start here
What DockDoor does, and what it costs
DockDoor adds window previews to the macOS Dock: point at an app's icon and its windows show, from every Space and display, minimized and hidden ones too. Click one to focus it, or close, minimize or quit from the preview. It also has an Option-Tab window switcher with search, gestures that snap windows, music controls with lyrics, and Folder Pop for Dock folders.
It's free and open source (GPL-3.0), with “no trial, no subscription and no paywall”, from its GitHub page or Homebrew. It needs macOS 13 or later and is updated often: 1.41.0 came out on October 15. DockDoor Pro is a separate app, a Dock replacement, at $20 once.
We make Koi, so read this with that in mind. Every fact about another app comes from that app's own site, checked October 26, 2026.
The picks
The best DockDoor alternatives for Mac in 2026
1. Koi
Best for: Simple Dock previews, inside an app that does much more
Rest the pointer on an app in the Dock and Koi shows its windows on this desktop above the icon, minimized ones too, each with its title and a small live picture. Click one to bring it forward, or × to close it. The pictures are taken on your Mac and never kept or sent.
Where DockDoor is better, plainly: it's free, it shows windows from other Spaces and displays, and it has a window switcher, layouts, snapping and much more. Koi's previews are one small part of Koi, which is $20 a month or Lifetime, paid once, with dictation, call recording, an assistant and a notch full of tools.
2. AltTab
Best for: Switching between every window from the keyboard
AltTab brings Windows' alt-tab to the Mac: a switcher across every window, minimized, hidden and on other Spaces, with a big preview of the one you pick. It has no Dock previews. The core is free and open source; Pro adds search and more styles for $9.99 once. macOS 12 or later. More in our AltTab alternatives.
3. HyperDock
Best for: Older Macs, and moving windows with keys
HyperDock was one of the first apps to put window previews on the Dock, with music and calendar panels on hover and window moving and snapping. It's $9.95. Its download page lists macOS up to Mojave, so check that it runs on yours. More in our HyperDock alternatives.
4. App Exposé, built in
Best for: Free, with nothing to install
macOS can already show one app's windows: Control-click its Dock icon and choose Show All Windows, or press Control and the down arrow. It fills the screen rather than showing small previews over the Dock.
Comparison
DockDoor vs the alternatives
From each app's own site. “Not listed” means the site doesn't mention it.
| Dock previews | Window switcher | Other Spaces | macOS | Price | |
|---|---|---|---|---|---|
| DockDoor | Yes | Yes | Yes | 13+ | Free |
| Koi | Yes | No | No | 14+ | $20 a month, or Lifetime, $199 once |
| AltTab | No | Yes | Yes | 12+ | Free; Pro $9.99 once |
| HyperDock | Yes | Not listed | Yes | Listed up to Mojave | $9.95 |
| App Exposé | Full screen | No | Yes | Built in | Free |
Honest take
When DockDoor is still the better pick
Stay on DockDoor if
- You want Dock previews and nothing else, for free.
- You work across several Spaces or displays and want every window in the preview.
- You want a window switcher, snapping or layouts too.
Choosing
Which one should you pick?
- Only Dock previews, free and full of options? DockDoor.
- Switching windows from the keyboard? AltTab.
- Dock previews plus dictation, call recording and an assistant in your notch? Koi.
- Nothing to install? App Exposé.
See how Koi does it on the Dock previews page, or the plans on the pricing page.
Keep exploring
The best HyperDock alternatives for Mac
HyperDock alternatives for newer Macs: DockDoor, Koi's Dock previews, AltTab and App Exposé. Window previews from the Dock, compared with prices.
The best AltTab alternatives for Mac
AltTab alternatives for Mac: DockDoor's switcher and Dock previews, Koi's Dock previews, and macOS's own ⌘Tab and App Exposé. What each does, with prices.
The best notch apps for MacBook in 2026
The best MacBook notch apps: Boring Notch and Atoll (free), Droppy, Alcove, DynamicLake, MediaMate, NotchDrop, and Koi. Music, AirDrop, battery and more.
Support
Frequently asked questions
Yes. It's free and open source, with no trial or paywall. DockDoor Pro, a separate Dock replacement, is $20 once.
Yes, on Option-Tab, with search. Koi doesn't have one.
No. Koi shows the app's windows on the desktop you're on, minimized ones too. DockDoor shows every Space and display.
Yes. Control-click the app's icon in the Dock and choose Show All Windows, or press Control and the down arrow. It fills the screen.