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Guide · Open source

How to use Betterfox: install user.js in Firefox

Updated · written with AI from the project's own documentation and checked against our catalogue data

Betterfox is a free, MIT-licensed user.js file that applies a curated list of Firefox about:config settings aimed at better privacy and security without adding third-party code. This guide is for Firefox users who are comfortable editing browser settings and following a setup guide. By the end you will know how to back up your profile, place user.js in the right folder, restart Firefox, and pick optional variants.

Firefoxyokoffing/Betterfox · ★ 11k · MIT

Quick start

  1. 1Back up your profile. Create a backup of your Firefox profile before making changes, following the wiki's backup guide.
  2. 2Download user.js. Get user.js from the official Betterfox repository on GitHub, either by saving the raw file or cloning the repo.
  3. 3Open your profile folder. Type about:profiles in the address bar, then click Open Folder under Root Directory for your profile.
  4. 4Move user.js into the folder. Place the user.js file in the profile folder you opened.
  5. 5Review overrides. Read Common Overrides and Optional Hardening and make any changes you need, since some tweaks can affect sites.
  6. 6Restart Firefox. Close and reopen Firefox so it applies the settings from user.js.
  7. 7Add an ad blocker. Install uBlock Origin and consider the recommended filter lists.

What Betterfox is and who it suits

Betterfox is a configuration file, not an extension. It contains a list of Firefox about:config preferences that Firefox reads when it starts. The project describes itself as an opinionated preference list with three goals: minimalism, efficiency, and privacy without causing site breakage.

It fits people who want privacy-focused defaults without installing extra software. It is a poor fit if you want zero breakage on every site, since the README says tweaks can affect site behavior, or if you use Chrome, Edge, or Safari, because it only targets Firefox and its forks.

Back up your Firefox profile first

Before changing anything, create a backup of your profile. The README links a backup guide in the project wiki. Changing preferences can alter how sites behave, so a backup lets you roll back.

Mozilla Firefox is the required browser. The README references Firefox 153 ESR or the current release, and a Betterfox branch for Firefox 153 ESR is available.

Download user.js and get it from the official source

Download the user.js file from the official repository. The README gives a direct link to the raw user.js on the main branch, and says to right-click and choose Save Link As. You can also clone the repository using the command below.

The README warns that some sites claim to be Betterfox. The official repository on GitHub is the only official source it names, so download from there.

  • Right-click the user.js link in the README and choose Save Link As
  • Or clone the repository
git clone https://github.com/yokoffing/Betterfox

Place user.js in your Firefox profile folder

Open Firefox and type about:profiles in the URL bar, then press Enter. For the profile you want to use, click Open Folder in the Root Directory section. Move the user.js file into that folder.

Firefox applies the settings when it restarts, so close and reopen the browser after placing the file.

  • Type about:profiles in the address bar and press Enter
  • Click Open Folder under Root Directory for the target profile
  • Move user.js into that folder
  • Restart Firefox
about:profiles

Review overrides and pick a variant

The README asks you to review Common Overrides and Optional Hardening in the wiki and make any changes you need before relying on the file. These pages describe settings that may change site behavior.

The main user.js is described as the essentials. Other files in the repository are Securefox (protect user data without causing site breakage), Peskyfox (a clean, distraction-free experience), and Smoothfox (optional, for smooth scrolling). Securefox, Peskyfox, and Smoothfox are guides that the user.js is curated from.

  • user.js: all the essentials
  • Securefox.js: protect user data with less breakage risk
  • Peskyfox.js: distraction-free browsing
  • Smoothfox.js (optional): smooth scrolling

Pair Betterfox with an ad blocker and secure DNS

The README recommends an ad blocker such as uBlock Origin, with the project's recommended filters. It also suggests enabling DNS-level protection with a provider of your choice, linked from the Optional Hardening wiki page.

Betterfox does not replace an ad blocker. The README presents these as separate steps to take after restarting Firefox.

  • Install uBlock Origin from Firefox add-ons
  • Consider the recommended filter lists
  • Enable DNS-level protection with a provider you choose

What people use it for

  • Tightening privacy defaults on a daily-use Firefox profile without installing extra software
  • Using Securefox or Peskyfox as a different balance of protection and cleanliness
  • Applying the same preferences to a Firefox fork such as Zen, Floorp, or Waterfox, though the README notes forks often modify Betterfox
  • Pairing a browser configuration with uBlock Origin for ad and tracker blocking

Frequently asked questions

Is Betterfox free?

Betterfox is released under the MIT licence, according to the repository. It is a free, open-source configuration file.

Do I need to install anything to use Betterfox?

You need Mozilla Firefox and the user.js file. You place user.js in your profile folder and restart Firefox, so no extension is required.

Where do I put the user.js file?

Open about:profiles, click Open Folder under Root Directory for your profile, and move user.js into that folder. Restart Firefox afterward.

Will Betterfox break websites?

The README says tweaks can affect site behavior and recommends reviewing overrides. Keep a profile backup so you can revert if a site misbehaves.

Does Betterfox work with Chrome or Safari?

No. Betterfox only targets Firefox and its forks, so it does not apply to Chrome, Edge, or Safari.

How does Betterfox compare to arkenfox or pyllyukko/user.js?

The README lists arkenfox user.js, pyllyukko/user.js, and Narsil/desktop_user.js as comparable projects and links a comparator for pyllyukko/user.js. This guide does not benchmark them, so compare their settings directly before choosing.

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Our verdict

Betterfox suits Firefox users who want a curated privacy preference file and are willing to back up their profile and review overrides. If you need zero site breakage, want a non-Firefox browser, or do not want to manage files in your profile folder, pick a different approach.

Install options & downloads