What is macos-window-styler?

macOS Window Styler is a small native Mac app that lets you change how your windows look on macOS 26 and later. Recent versions of macOS ship with a newer, flatter window style, and this tool lets you switch back to older looks or build your own custom appearance instead. It comes with three built in presets named Tahoe, Sequoia, and OS X, each mimicking a different era of macOS window design. Beyond the presets, the app offers fully customizable window appearance settings, so you can adjust the look beyond the three defaults if none of them match what you want. Changes show up as an instant preview, and applying a style is a single click. The app is built natively for the Mac using SwiftUI, Apple's modern app building framework, so it should feel like a normal Mac application rather than something bolted on. The source code is fully open, though the README does not state which specific open source license applies. To use it you need a Mac running macOS 26 or later. You can download a ready to run build from the project's Releases page, or clone the repository and build it yourself using Xcode, Apple's development tool. The project credits a Reddit post by a user named Aacha_ladka, whose research found hidden system settings that macOS uses to control window appearance. This app takes that discovery and wraps it in a simple graphical interface so anyone can use it without touching terminal commands. The README also notes the project is affiliated with and recognized by the LINUX DO community.