The short version: Yes, Rectangle is safe. It’s open source under the MIT license, so its entire codebase is public on GitHub for anyone to inspect. It asks for macOS Accessibility permission — the standard requirement for any window manager — and collects no telemetry. The Accessibility prompt looks alarming but is completely normal, and below is exactly what it does and doesn’t allow.
The short, honest answer
Rectangle is one of the safer apps you can put on a Mac, for a specific and verifiable reason: you don’t have to take anyone’s word for it. The code is open source and published on GitHub, so the app’s exact behavior is auditable by anyone able to read it — and by the many people who already have. Closed-source apps ask for trust. Open-source apps hand you proof.
Still, “it’s open source” isn’t satisfying if you don’t know what that implies or why Rectangle needs the permission it requests. So let’s walk the three things people actually worry about: the source code, the Accessibility permission, and privacy.
Open source: what it means for you in practice
Rectangle ships under the MIT license, one of the most permissive and widely trusted open-source licenses going. In plain terms, the complete source code sits publicly on GitHub. Anyone can read every line, see exactly what the app does, check whether it phones home, and confirm there’s nothing hidden inside.
This matters even if you’ll never read a line of code yourself. Open-source software of any popularity draws scrutiny from developers, security-minded users, and package maintainers. The Rectangle app is popular and long-established, so if it did something shady — quietly harvested data, contacted odd servers, behaved unlike it claims — someone in that community would have caught it and said so publicly. That collective auditing is a genuine safety net closed apps simply don’t have.
The Accessibility permission: why it’s needed, what it allows
Here’s the part that spooks new users. On first launch, Rectangle requests Accessibility access under System Settings → Privacy & Security → Accessibility. macOS wraps this permission in serious-sounding language, and that scares people off. It shouldn’t, and here’s the reasoning.
Moving and resizing other apps’ windows is, by design, something macOS won’t allow without explicit permission. Accessibility access is the exact permission Apple provides for that kind of control. Every window manager on the Mac — Rectangle, Magnet, BetterSnapTool, Moom, all of them — needs it, because there’s no other route to repositioning windows system-wide. Rectangle isn’t asking for anything exotic; it’s asking for the one permission its whole job depends on.
What that permission grants is the ability to move, resize, and position windows. What Rectangle does with it is precisely what you observe: snap windows when you drag or hit a shortcut. The permission is powerful in the abstract, which is why Apple gates it, but Rectangle’s use of it is narrow, visible, and verifiable in the source.
Privacy: what Rectangle actually collects
The privacy answer is brief: essentially nothing. Rectangle isn’t built to gather data, and because it’s open source, that isn’t just a claim — it’s checkable. There’s no ad business behind it, no data-harvesting model, no reason to track you, and the code bears that out.
Set that against the usual deal with free software, where “free” often means you’re the product. Rectangle is free in the other sense — free as in open source, developed in the open, with no covert monetization of your behavior. The optional paid Rectangle Pro is how the project funds itself, not your data.
Is it safe to install outside the App Store?
This snags people because Rectangle isn’t on the Mac App Store — it’s a direct download or Homebrew install. Some read “not on the App Store” as “risky.” It isn’t. Rectangle skips the App Store because Apple’s sandboxing rules clash with the Accessibility-level control a window manager needs, not because it couldn’t clear review on safety grounds.
To install safely, grab Rectangle for Mac from its official site or through Homebrew — both legitimate sources. As with any app pulled from outside the App Store, macOS Gatekeeper verifies it’s properly signed before it runs. Download from the official channel and you’re getting the real, signed application.
The honest verdict
Rectangle is safe, and unusually so, because its safety is verifiable rather than promised. Open source under the MIT license, publicly auditable on GitHub, watched by a large community, no telemetry, and a single permission that every window manager needs and that Rectangle uses exactly as advertised. The Accessibility prompt is normal, the App Store absence is a distribution choice rather than a warning sign, and there’s no data-harvesting model hiding underneath.
If anything, Rectangle is a template for how a Mac utility should handle trust: do one thing, ask only for what that thing requires, and open the code so nobody has to take your word for it. Install from the official source, grant the Accessibility permission it asks for, and you’re set. If snapping ever stops working later, that’s almost always this permission getting reset by a macOS update — a two-minute re-grant, not a safety issue.
Frequently asked questions
Is Rectangle safe to install on a Mac?
Yes. Rectangle is open source under the MIT license, so its full code is publicly auditable on GitHub, and it’s scrutinized by a large community. It collects no telemetry and asks only for the Accessibility permission every window manager needs. Install it from the official site or Homebrew and it’s a safe, signed app.
Why does Rectangle need Accessibility permission?
Because macOS won’t let any app move or resize other apps’ windows without it. Accessibility access is the specific permission Apple provides for that kind of system-wide control, and every Mac window manager requires it. Rectangle uses it only to snap and position windows.
Does Rectangle collect my data?
Essentially no. Rectangle has no advertising or data-harvesting model, and because it’s open source, that claim is verifiable in the code rather than just stated. There’s no hidden tracking; the project is supported by the optional paid Rectangle Pro, not your data.
Is it risky that Rectangle isn’t on the App Store?
No. Rectangle isn’t on the App Store because Apple’s sandboxing conflicts with the Accessibility control a window manager needs, not for safety reasons. Downloaded from the official site or Homebrew, it’s properly signed and verified by macOS Gatekeeper like any legitimate app.