# BlockBlock for Mac

> Asks before anything sets itself to run at startup.

BlockBlock watches the places malware uses to stay on a Mac, such as launch agents, login items and background tasks, and asks you to allow or block each new entry. Free and open source, from the makers of LuLu.

## Facts

- Price: Free and open source
- Developer: Objective-See
- Category: Security & Privacy
- Website: https://objective-see.org/products/blockblock.html
- Homebrew cask: blockblock
- Source code: https://github.com/objective-see/BlockBlock
- License: GPL-3.0
- GitHub stars: 864
- Last commit: 2026-09-14
- Facts checked: 2026-10-19
- MacWorthy page: https://macworthy.com/apps/blockblock/

## Install

Homebrew:

```sh
brew install --cask blockblock
```

## Questions

### Is BlockBlock free?

Yes. BlockBlock is free and open source under the GPL-3.0 license. The source code is on GitHub at objective-see/BlockBlock.

### Where can I download BlockBlock for Mac?

Download BlockBlock from the developer's website (objective-see.org) and GitHub. MacWorthy links only to official sources.

### Can I install BlockBlock from the Terminal?

Yes. With Homebrew, run `brew install --cask blockblock`.

### What are good alternatives to BlockBlock?

Other security & privacy apps for Mac worth a look are KnockKnock (open source), LuLu (open source), OverSight (open source) and Secretive (open source).

## Alternatives in Security & Privacy

- [KnockKnock](https://macworthy.com/apps/knockknock/): See what's persistently installed. (Open source)
- [LuLu](https://macworthy.com/apps/lulu/): The free, open-source outbound firewall. (Open source)
- [OverSight](https://macworthy.com/apps/oversight/): Know when your mic and camera turn on. (Open source)
- [Secretive](https://macworthy.com/apps/secretive/): SSH keys that never leave the Secure Enclave. (Open source)
- [Little Snitch](https://macworthy.com/apps/little-snitch/): See and control every network connection. (One-time purchase)
- [Strongbox](https://macworthy.com/apps/strongbox/): KeePass and Password Safe, made native. (Free + Pro)
- [Tailscale](https://macworthy.com/apps/tailscale/): A private network for all your devices. (Free + Pro)

Tags: security, malware, open source