Immediate Fix: Bypass Gatekeeper and Check Architecture
The most common reason Notion fails to install on Mac is Apple’s Gatekeeper security. This feature prevents the installation of apps not directly from the App Store or identified developers.
To fix this, go to System Settings > Privacy & Security. Scroll down to the “Security” section. If you see a message saying Notion was blocked, click “Open Anyway” and enter your administrator password.
Verify Your Processor Type
Notion provides two different versions for Mac: Intel and Apple Silicon (M1/M2/M3). Installing the wrong version often results in an installation loop or a “damaged” file error.
| Mac Model | Installer Type | Action |
|---|---|---|
| MacBook Pro/Air (M1, M2, M3) | Apple Silicon | Download “Mac with Apple Chip” |
| Older Macs (pre-2020) | Intel | Download “Mac with Intel Chip” |
Technical Explanation: Notarization and Quarantine Flags
When you download Notion from the web, macOS attaches a “quarantine flag” to the file. This tells the OS to run a deep security scan before allowing execution.
If the notarization check fails or the download is interrupted, the installer fails to launch. This is often caused by a corrupt `.dmg` file or outdated certificates in the macOS keychain.
Advanced users can manually strip the quarantine flag using the Terminal if the standard “Open Anyway” button does not appear.
# Remove the quarantine attribute from the Notion installer
xattr -d com.apple.quarantine ~/Downloads/Notion-*.dmg
Alternative Methods: Using Homebrew or Manual Cleanup
If the standard `.dmg` installer continues to fail, you can use the Homebrew package manager. This bypasses the browser-based download issues and installs Notion directly via the command line.
# Install Notion via Homebrew Cask
brew install --cask notionClean the Application Cache
Sometimes, remnants of a previous failed installation prevent a new one. You must clear the local cache folders before trying again.
Open Finder, press Cmd+Shift+G, and delete the following directories:
- ~/Library/Application Support/Notion
- ~/Library/Caches/notion.id
- ~/Library/Saved Application State/notion.id.savedState
After deleting these files, restart your Mac and attempt a fresh installation of the correct architecture version.