# is64bit > Check whether operating system CPU architecture is 64-bit or 32-bit This package also works in the browser. It can be useful to serve the correct binary for download. On Node.js, [`process.arch` / `os.arch()`](https://nodejs.org/api/process.html#processarch) is generally not useful as it returns the CPU architecture for which the Node.js binary was compiled, not the actual system architecture. ## Install ```sh npm install is64bit ``` ## Usage ```js import {is64bit} from 'is64bit'; // On ARM64 macOS console.log(await is64bit()); //=> true ``` ## API ### is64bit() Returns a `Promise` for whether the operating system CPU architecture is 64-bit. ### is64bitSync() Returns a `boolean` for whether the operating system CPU architecture is 64-bit. **Note**: Prefer the async version for browser or cross-platform usage as it has a more reliable check. ## Related - [system-architecture](https://github.com/sindresorhus/system-architecture) - Get the operating system CPU architecture