A simple privacy helper for Firefox profiles.
PrivFox is not a browser. It is a small Windows PowerShell script that applies privacy-focused Firefox preferences to your local Firefox profiles by creating or updating Firefox's user.js configuration file.
PrivFox helps disable or reduce:
- Mozilla telemetry and data reporting
- Firefox studies and experiments
- Crash report auto-submission
- Firefox Suggest / QuickSuggest sponsored suggestions
- Trending/search suggestions in the address bar
- Sponsored content on the new tab page
- Extension recommendations
Before changing anything, PrivFox creates a backup of an existing user.js file if one is already present.
- Windows 10 or Windows 11
- Mozilla Firefox installed
- Firefox must have been opened at least once so a profile folder exists
- Download or clone this repository.
- Close Firefox completely.
- Right-click
privfox.ps1. - Choose Run with PowerShell.
If Windows blocks scripts, open PowerShell in the repository folder and run:
powershell -ExecutionPolicy Bypass -File .\privfox.ps1Then start Firefox again.
PrivFox looks for Firefox profiles here:
%APPDATA%\Mozilla\Firefox\Profiles
For each profile, it writes:
user.js
If user.js already exists, PrivFox creates a backup first:
user.js.backup-YYYYMMDD-HHMMSS
Open your Firefox profile folder and either:
- delete
user.js, or - restore the backup file created by PrivFox.
After that, restart Firefox.
Some Firefox preferences may change, disappear, or behave differently in future Firefox versions. PrivFox is intentionally simple and transparent, so you can inspect every preference before running it.
For project-related contact:
byaldon@proton.me
PrivFox is an independent project and is not affiliated with, endorsed by, or sponsored by Mozilla or Firefox.
Firefox is a trademark of the Mozilla Foundation.
This project is released under the MIT License.