How to Install Downloaded Apps on macOS Safely

Securely install third-party apps on your Mac by managing Gatekeeper settings and verifying application integrity.

1. Verify the application source. Only download software from official developer websites or trusted repositories. Check the URL in your browser to ensure it matches the official domain before clicking the download link.
2. Mount the disk image. Locate the downloaded .dmg file in your Downloads folder and double-click it. This mounts the disk image to your desktop and opens a Finder window containing the application or an installer package.
3. Inspect the application package. Right-click the application icon or the .pkg installer file within the mounted disk image. Select Get Info from the contextual menu and confirm the developer name matches your expectations in the General section.
4. Bypass Gatekeeper for unsigned apps. If you receive a prompt stating the app cannot be opened because it is from an unidentified developer, do not click OK. Instead, navigate to System Settings > Privacy & Security, scroll to the Security section, and click Open Anyway to authorize the specific file.
5. Move the app to Applications. Drag the application icon from the disk image into the Applications folder alias provided in the window, or drag it directly to the Applications folder in your Finder sidebar. This installs the app to your system directory.
6. Eject the disk image. Once the installation is complete, drag the mounted disk image icon from your desktop to the Trash to eject it. Alternatively, click the Eject button next to the drive name in the Finder sidebar.