Cordon is a macOS menu bar app that blocks ads and trackers on your Mac. It runs a local filter on your machine and works across browsers and most apps.
- Download installer (macOS disk image)
- Download ZIP (macOS archive)
Open the installer or unzip the archive, then move Cordon to your Applications folder. See How to use below for certificate setup and enabling protection.
Requests - see blocked ads and trackers in real time
Filter Lists - turn filter lists on or off by category
- macOS
To build from source you also need Xcode. No Go or other tools are needed. The blocking engine is included in the repo.
- Open
Cordon.xcodeprojin Xcode - Build and run (Cmd+R)
After you launch Cordon, look for the shield icon in the menu bar (top right of your screen).
- Click the Cordon icon in the menu bar
- Click Install Certificate
- macOS will ask for your password. Enter it when prompted
- If macOS asks you to trust the certificate, click Always Trust
This certificate lets Cordon filter HTTPS traffic safely on your Mac. You only need to do this once.
To check it worked, open Cordon, go to Settings, and click Verify Certificate Trust.
- Click the Cordon icon in the menu bar
- Click Enable Protection
Wait one to two minutes the first time while filter lists load. When protection is on, the shield icon changes and ads should start getting blocked.
To turn it off, click the icon again and choose Disable Protection.
Click the menu bar icon and choose Open Cordon to see more options:
| Tab | What it does |
|---|---|
| Requests | See blocked ads and trackers in real time |
| Filter Lists | Turn filter lists on or off (ads, privacy, malware, regional) |
| Rules | Add your own blocking rules, one per line |
| Settings | Certificate, ignored hosts, launch at login |
You do not need to open the main window for basic use. Install the certificate, enable protection, and you are done.
If Brave or Chrome show a certificate warning:
- Reinstall the certificate from Settings
- Turn off Secure DNS in the browser privacy settings
- Turn off QUIC in
brave://flagsorchrome://flags - Quit and reopen the browser
Some apps ignore the system proxy or use their own security. Banking apps may not work with protection on. You can add domains to Ignored Hosts in Settings to skip filtering for specific sites.
Cordon only protects the Mac it runs on. It does not block ads on other devices on your network (phones, TVs, etc.).
- Disable protection from the menu bar
- In Settings, click Uninstall Certificate
- Delete the app
To remove leftover files:
rm -rf ~/Library/Application\ Support/Cordon/