How to Install and Use Firefox with Syncing on elementary OS

Firefox is one of the most recognisable browsers around, and it runs beautifully on elementary OS. Plenty of users pick it over the default Epiphany (GNOME Web) because of its flexibility, the deep extension catalogue, and the cross-device syncing that just works once configured. If you're coming across from Windows or macOS, the transition feels familiar. If you've always been on Linux, you'll still appreciate having a mature alternative with a polished sync layer.

Syncing bookmarks, tabs, passwords, and history has quietly become something people rely on without thinking about it. Australians often move between an NBN connection at home in the suburbs, mobile data while catching the train through inner Sydney or Melbourne, and a shared computer at the office in the CBD. Keeping the same browsing state across all those touchpoints saves a lot of fumbling. Firefox Sync handles this seamlessly when set up properly, and on elementary OS the whole process is straightforward.

This walkthrough takes you through installation, account creation, sync configuration, extension handling, and the small handful of fixes that crop up from time to time. You'll find command-line steps alongside GUI instructions, plus a few tips that reflect how people actually use their machines day to day.

Preparing Your System Before Installing Firefox

Before installing anything, refresh the package database so you pull the latest metadata from your configured repositories. Open Terminal from the Applications menu, or press the Super key and type "terminal" — that works on both elementary OS 7 and the newer 8 (Cirrina) release.

Run sudo apt update to refresh the package list, then sudo apt upgrade to apply any pending updates. If you're on a metred NBN plan through Telstra or a similar provider, an upgrade of a few hundred megabytes can chew through your monthly allowance faster than you'd expect. Schedule big updates when you're on a free or un-metred connection, or duck into a café in Fitzroy or Newtown that doesn't gate the Wi-Fi. Restarting after a kernel update is a good habit too, because it clears out stale modules that can interfere with browser sessions later on.

If Firefox isn't already installed, the system may be running a transitional package or a snap build. Check what's there with apt list --installed | grep -i firefox. Some Australian users on lower-spec laptops — older ThinkPads, refurbished Chromebooks, that sort of thing — report that the snap version can feel sluggish, so removing it before installing the official .deb from Mozilla's repo usually gives a snappier result.

Installing Firefox on elementary OS

elementary OS is built on Ubuntu, so you have two clean paths: pull from the Ubuntu archive, or add Mozilla's official APT repository. The Ubuntu archive ships whatever version your base release supports, which on elementary OS 8 is generally Firefox 115 ESR or the current stable depending on the snapshot you installed. For the latest stable, the Mozilla route is the way to go.

To add the Mozilla repo, first install the signing key:

sudo install -d -m 0755 -o root -g root -d /etc/apt/keyrings
wget -q https://packages.mozilla.org/apt/repo-signing-key.gpg -O- | sudo tee /etc/apt/keyrings/packages.mozilla.org.asc > /dev/null

Then add the repository itself:

echo "deb [signed-by=/etc/apt/keyrings/packages.mozilla.org.asc] https://packages.mozilla.org/apt mozilla main" | sudo tee /etc/apt/sources.list.d/mozilla.list > /dev/null

After that, run sudo apt update and sudo apt install firefox. The browser appears in your applications menu. If you'd rather pin the ESR branch, append firefox-esr to the install command instead. A lot of Australian sysadmins prefer ESR for fleet stability because the longer support window means fewer forced restarts during business hours.

Pin Mozilla's packages higher than Ubuntu's so you don't get downgraded during routine updates:

echo '
Package: *
Pin: origin packages.mozilla.org
Pin-Priority: 1000' | sudo tee /etc/apt/preferences.d/mozilla

Setting Up a Mozilla Account for Cross-Device Syncing

Firefox Sync rides on a free Mozilla account, which you can create directly from inside the browser. Click the hamburger menu in the top-right corner, choose "Sign in to Sync," then either sign in with an existing account or create a new one. You'll need an email address — any provider works, including the local ones Australians tend to use, like iCloud, Gmail, or even a BigPond address if you still have one floating around from the early NBN rollout.

Once you're signed in, Firefox will offer to sync immediately or let you pick what to include. The default is bookmarks, history, open tabs, add-ons, and passwords. If you'd rather sync just a subset — say, bookmarks and tabs but not passwords because you use a separate manager — you can fine-tune this from the Sync preferences panel later on.

The first sync can take a moment if you have a large bookmark collection. Anything over a couple of thousand entries will spend a bit of time churning through the upload. If you're on a slower NBN tier like FTTN or HFC and you're hitting peak evening congestion, the initial upload can feel like it's dragging on, but it only happens once. Subsequent syncs are tiny diffs and happen in seconds.

Configuring Bookmarks, Tabs, and History Sync

The sync preferences live at about:preferences#sync in Firefox, which you can reach by typing that into the address bar. From here you can toggle each category on or off and trigger a manual sync if something hasn't caught up.

A practical tip for Australian users who frequently switch between a desktop at work and a phone on the train: enable tab syncing, but think twice about leaving "send tabs to all devices" turned on if you share your screen with family or flatmates. Tabs can sometimes reveal things you'd rather not have appear mid-shift — a recipe on your phone while you're cooking dinner, for instance. Mozilla encrypts everything end-to-end with your account password, so even Mozilla staff can't read the content, but local visibility on a shared screen is worth considering.

For history syncing, be aware that the default window is 30 days. If you want longer retention, that's not directly configurable in Firefox Sync — you'd need to keep local history longer and only sync the recent slice. Bookmarks, on the other hand, sync in their full depth and structure, so nested folders and custom orderings come through intact on the receiving device.

Managing Extensions, Passwords, and Privacy While Syncing

Firefox Sync also handles add-ons by default, which is handy if you rely on the same extensions across devices — uBlock Origin, Bitwarden, Dark Reader, and the like all sync cleanly. There's a catch though: if you've ever used Sync on an Android phone that also had a few older, incompatible extensions installed, those can sometimes try to re-install on your Linux machine and produce "could not be verified" warnings. Clear out the unwanted add-ons from your synced device first, then trigger a manual sync to clean up the database.

For passwords, Firefox's built-in manager is decent but basic compared to dedicated tools. If you already use Bitwarden or 1Password, you might want to disable password syncing in Firefox to avoid duplicate entries. Many Australians who travel between Brisbane for work and a regional town in Queensland prefer a centralised vault so they can access the same logins on a hotel Wi-Fi network as easily as on the home NBN.

Privacy-wise, Firefox Sync uses your account password to derive an encryption key. That password is never sent to Mozilla's servers, so losing it means losing access to your synced data — there's no recovery option. Pick a strong, unique password and store it somewhere safe, ideally in a separate password manager. Two-factor authentication on the Mozilla account itself is worth turning on too, as it adds a layer against account takeover if your email password ever leaks in one of those big breaches.

Troubleshooting Common Sync Issues on elementary OS

If syncing refuses to start, the first thing to check is whether the browser can reach Mozilla's servers. Run curl https://accounts.firefox.com from a terminal; if that fails, the problem is network-side rather than Firefox. Common culprits on Australian networks include DNS issues with the default ISP resolver, captive portals in hotels and serviced apartments, or an NBN outage affecting your area. Aussie Broadband and Superloop customers tend to report fewer DNS hiccups than those on legacy Telstra or Optus connections, but anything can happen during a storm.

For DNS problems, switching to a public resolver like 1.1.1.1 or 8.8.8.8 in your network settings often helps. elementary OS uses NetworkManager, so you can set this through the GUI by editing your Wi-Fi connection and adding the DNS servers manually under IPv4 settings.

If sync starts but stalls partway, signing out and back in often clears things up. Go to about:preferences#sync, click your email, then "Sign out," and sign in again. Make sure your system clock is accurate, because sync tokens have short validity windows and a skewed clock can cause authentication failures. elementary OS handles time sync through systemd-timesyncd by default, so sudo timedatectl status should show "System clock synchronized: yes."

For persistent issues, the Sync logs at about:sync-log can be useful. Look for entries tagged "ERROR" or "WARN" and note the timestamp when you last tried to sync. Repeated 401 or 403 errors usually mean your account token has expired — signing out and back in regenerates it.

Once Firefox is running on elementary OS with Sync turned on, it becomes one of those small conveniences that quietly ends up mattering a lot. Your bookmarks, tabs, logins, and add-ons follow you from a desktop in the home office to a laptop on the kitchen table to a phone tapping into the local café's Wi-Fi, and you stop thinking about which device you're on. The whole point is that it feels invisible. Spend ten minutes getting the account and preferences set up properly now, and you'll save yourself hours of "where did I save that link?" hunting for years to come.