AltTab is a free, open-source Mac utility that replaces the default ⌘Tab application switcher with a visual, thumbnail-based window switcher — giving macOS the kind of instant, full-preview task-switching that power users have long envied in other desktop operating systems.
What is AltTab?
AltTab is a macOS window-switcher replacement that shows live thumbnail previews of every open window the moment you hold a configurable hotkey. Unlike the native ⌘Tab experience — which shows app icons only and hides windows behind minimise state — AltTab surfaces every individual window as a pickable card, including minimised and fullscreen spaces, so you always see exactly what you're switching to before you let go of the key.
The project is actively maintained, ships as a native Mac app, and installs in seconds. There is nothing to subscribe to and nothing to unlock.
What does AltTab do best?
AltTab's biggest win is eliminating the cognitive overhead of blind switching. When I have three browser windows, two Finder windows, and a pair of terminals open, the stock switcher forces me to release ⌘Tab and guess. AltTab shows me a live grid of every window with enough thumbnail detail to read the content at a glance — I pick with confidence every time.
- Per-window (not per-app) switching — each window gets its own card, not buried under an app group
- Minimised and fullscreen awareness — windows you've sent to the Dock or pushed to a Space still appear
- Keyboard and mouse navigation — arrow keys, number shortcuts, or a click all work
- Configurable hotkeys — default is ⌥Tab (Option-Tab) so it doesn't fight native ⌘Tab; remap anything
- Preview on hover — hovering a thumbnail briefly expands it, letting you confirm content without committing
- Appearance customisation — choose from multiple built-in themes, set thumbnail size, control how many rows appear, and match your system accent colour
The app handles multi-monitor setups gracefully too, showing the switcher on whichever display your cursor is on and letting you filter to windows on the current screen alone if you prefer.
Is AltTab free?
Yes — AltTab is completely free to download and use, with no premium tier, no nag screen, and no analytics. It is open-source software hosted on GitHub, which means the community audits the code and contributes translations (30+ languages at last count). You can inspect exactly what it does before running it.
Who should use AltTab?
Anyone who routinely juggles more than five or six open windows will feel the difference immediately. I'd particularly recommend it to developers switching between editor, terminal, browser, and documentation; designers toggling between reference and canvas; and anyone migrating from Windows who finds macOS task-switching genuinely frustrating.
If you only ever have two or three apps open and you always keep windows maximised in separate Spaces, the default ⌘Tab experience is probably sufficient and AltTab's extra surface area would go unused. That's the honest assessment. But for anyone with a busy desktop, this utility is close to essential.
What are the best AltTab alternatives?
The closest native comparison is macOS Mission Control — powerful but mouse-centric and slow to invoke. Witch (by Many Tricks, paid) offers a comparable per-window list switcher with a menu-bar aesthetic. HiDock adds a preview strip to the Dock rather than replacing the switcher. Raycast and Alfred both have window-switching extensions, but they're keyboard-list-only with no thumbnails, which suits different workflows. AltTab's combination of thumbnail previews, minimised-window support, and zero price is genuinely hard to match.
How does AltTab compare to macOS Mission Control?
Mission Control is a swipe-or-hotkey gesture that spreads every window across the full screen — excellent for spatial orientation, less ideal for rapid back-and-forth switching. AltTab sits in a different lane: it appears inline over your current context without a full-screen transition, lets you navigate with the same keystrokes you'd already be holding, and dismisses the moment you release the key. The two are complementary rather than competing; I keep both active and use Mission Control for spatial re-organisation and AltTab for moment-to-moment switching.
