If you work with multiple AI tools throughout the day — ChatGPT in one tab, Claude in another, Gemini for a third opinion, Cursor or Windsurf for code, maybe a local model running in the terminal — you know the friction. macOS's native Cmd+Tab switches between apps, not windows. That distinction didn't matter much before. Now it's the bottleneck.

Alt-Tab-macos is a free, open-source window switcher that fixes this. It's been around since 2019, has 15k GitHub stars and 7 million downloads. But it's never been more relevant than right now, in 2026, when the average knowledge worker's desktop looks like a cockpit.

The problem

The default macOS app switcher was designed for a world where you had Safari, Mail, Finder, and maybe iTunes open. You pressed Cmd+Tab, you cycled through four icons, done.

That world is gone. A realistic 2026 desktop has ChatGPT in a browser tab, Claude in another tab, Claude Code in a terminal, Gemini in yet another tab, a coding IDE with AI built in, maybe a local Ollama instance in another terminal, Slack with AI thread summaries, Notion with AI writing, and your actual work somewhere in between.

All of these are "Safari" or "Chrome" to Cmd+Tab. The switcher shows you one Chrome icon. Which of your twelve Chrome windows is it going to focus? The one you wanted? Probably not. You end up clicking through Mission Control, or worse, minimizing windows one by one until you find what you need.

This is not a minor annoyance. When you're comparing outputs from three different AI models, the speed at which you can switch between them directly affects the quality of your evaluation. If switching takes five seconds instead of half a second, you've already forgotten what the first model said.

What Alt-Tab does

Alt-Tab-macos replaces the native app switcher with a window-level switcher. Press the hotkey and every open window appears as a thumbnail — not every app, every window. Each browser tab that's in its own window, each terminal session, each IDE instance — all visible at a glance, all accessible with a single keystroke.

• Window thumbnails — live previews of every open window, not just app icons
• Direct window switching — go straight to the specific window, not just the app
• Window actions — minimize, close, or fullscreen any window right from the switcher
• Customizable shortcuts — bind it to any key combination that feels natural
• App blacklisting — exclude apps you never want to see in the switcher

It's a 7MB download. Universal binary, runs on Apple Silicon natively. No telemetry, no account, no subscription. GPL-3.0 licensed. The kind of software that used to be unremarkable and is now, somehow, radical.

The AI workflow

Here's what AI multitasking actually looks like with Alt-Tab. You're writing a technical document. You have three AI conversations going:

• Claude for deep reasoning — you're asking it to review your architecture decisions
• ChatGPT for breadth — you're asking it for alternative approaches you haven't considered
• Gemini for the Google ecosystem angle — you're checking if there's a GCP service that does what you're building from scratch

Each of those is in its own browser window. Without Alt-Tab, switching between them means: Cmd+Tab to Chrome, then Cmd+` to cycle through Chrome windows until you find the right one. With three windows, that's tolerable. With twelve — which is where most people actually are — it's unusable.

With Alt-Tab, you press one hotkey, see thumbnails of every window including the page titles, arrow-key or click to the one you want. The whole interaction is under a second. You can keep your mental model of what each AI said because you're not losing five seconds of context every time you switch.

Window previews matter more than you think

The thumbnails aren't just pretty. They're the fastest way to identify which conversation is which. AI chat interfaces all look similar — a text input at the bottom, messages above. The native macOS app switcher shows you a Chrome icon for all of them. Useless.

Alt-Tab's thumbnails show you the actual content. You can see the purple of Claude's UI, the green of ChatGPT, the blue of Gemini. You can see whether a conversation is long or short, whether there's code in the response. You're pattern-matching visually, which is orders of magnitude faster than reading window titles.

This is the same principle behind why browser tab previews work on hover, why Exposé was a breakthrough when Apple introduced it, and why spatial memory matters in interface design. You remember where things are and what they look like, not what they're called.

Why not Mission Control

macOS has Mission Control. It shows all your windows. But it has three critical problems for AI workflows:

• No keyboard navigation — you have to reach for the trackpad and click. Every time. This breaks flow.
• Rearranges windows spatially — windows shrink and scatter to fit the screen, destroying your spatial memory. The Claude window that was on the left isn't on the left anymore.
• Requires a dedicated gesture or key — it's not wired into the alt-tab muscle memory. It's a separate mode you consciously enter and exit.

Alt-Tab is better because it's inline. It appears where you are, it's navigable with the keyboard, and it dismisses the moment you release the modifier key. There's no mode switch. It's the same cognitive cost as looking at a menu.

Setup

Install via Homebrew:

1brew install --cask alt-tab

Or download the .dmg from the official site. Open it, grant accessibility permissions when prompted, and it replaces Cmd+Tab immediately. No restart needed.

The first thing you'll want to do is open Preferences and set up your shortcut. The default Option+Tab is fine for most people, but you can rebind it to Cmd+Tab if you want to replace the native switcher entirely.

My configuration

After a few weeks of heavy AI multitasking, this is the setup I've settled on:

• Shortcut: Option+Tab for all windows, Cmd+Tab left as native for app-level switching when I want it
• Appearance: Titles style — shows window title text alongside thumbnails, which helps distinguish between AI chats with similar visual layouts
• Blacklisted apps: Finder, System Preferences, Calculator — things I never switch to via keyboard
• Show on: Screen including mouse — so it always appears where I'm looking

The key insight is keeping each AI in its own browser window, not just its own tab. Alt-Tab switches between windows. If all your AIs are tabs in one window, you're back to square one. Pop them out: right-click the tab, choose "Move Tab to New Window".

Comparison

The bigger picture

The reason Alt-Tab matters now, in 2026, is not because it's new. It's because the way we use computers changed and the operating system didn't keep up. macOS was designed around the idea that you use one app at a time and occasionally switch. The AI era turned every knowledge worker into someone running parallel conversations with multiple intelligence systems simultaneously.

That's a fundamentally different interaction model. You're not switching between "writing" and "email". You're switching between "Claude's take on my database schema" and "ChatGPT's take on my database schema" and "the actual schema in my IDE". The windows are semantically related. The speed of switching between them determines whether you can hold the comparison in your head or whether you have to write it down.

Apple will probably build this into macOS eventually. They'll call it something like "Intelligent Window Switching" and present it as a breakthrough at WWDC. Until then, Alt-Tab-macos is the answer. Free, fast, 7MB.

Install it. Pop your AI chats into separate windows. Press Option+Tab. That's it. You'll wonder how you worked without it.