Google has made ADB and fastboot available as a standalone package, meaning users no longer need to download them with Android Studio or the Android SDK.

You can get the platform tools for Windows, Linux, or Mac direct from Google's servers. You get a ZIP file containing the platform tools folder with ADB, fastboot, and a few other tools.

Both of these tools come with the Android SDK, however that’s an extremely large download that, frankly, most users who are interested in ADB and fastboot don’t need.