Firefox is fully supported
The FocusDragon extension is listed on Mozilla's Add-ons store (AMO) and installs in one click, the same way Chrome and Safari do. URL-level blocking, AI classifier grounding, and per-tab interventions all work. The only Firefox-specific gotcha worth knowing about is that extensions are off by default in Private Windows — you have to flip a second toggle.
Install
- 1. Open Firefox and navigate to https://addons.mozilla.org/addon/focusdragon/.
- 2. Click "Add to Firefox". Firefox shows a permissions dialog — click "Add" to confirm.
- 3. Optional: pin the FocusDragon icon to the toolbar so you can see its status at a glance. Right-click the icon and choose "Pin to Toolbar", or use the toolbar's overflow menu to drag it into place.
Allow in Private Windows
The number-one way users bypass a browser-extension blocker is by opening a private window. Firefox treats private mode as a separate permission surface and ships every extension disabled there by default. You have to opt FocusDragon in explicitly, or private windows will simply walk past every URL-level rule.
- 1. In Firefox, open about:addons in the address bar.
- 2. Find FocusDragon in the list and click it.
- 3. Set "Run in Private Windows" to "Allow".
What's blocked
- Whole-domain blocks — enforced at DNS level via /etc/hosts, so even Firefox can't reach the domain.
- URL-level blocks — e.g. youtube.com/watch but not youtube.com/yt-studio, handled by the extension.
- AI classifier coverage — page-text grounding works in Firefox tabs just like Chrome and Safari.
- Per-tab interventions — Hard and Nudge tiers can close a single drifting tab without touching the rest of the browser.
The Mac app's guided setup will open the AMO listing and about:addons side-by-side automatically when you click "Set up Firefox extension" in the app — you don't have to navigate to either URL by hand.