Firefox ESR 140.16.0 for Windows

Firefox ESR 140.16.0 is the Extended Support Release of Mozilla Firefox for Windows, the edition of the browser that Mozilla maintains for enterprises and other organisations. It changes features less often than regular Firefox while still receiving security fixes, and you can download Firefox ESR for free from Mozilla.

System requirements

On GNU/Linux, glibc 2.17 or higher is required (2.28 or higher on arm64), according to Mozilla's ESR requirements page.

How ESR differs from regular Firefox

Regular Firefox receives new features in frequent releases. The Extended Support Release keeps one feature set for a long period and only adds security and stability fixes on top, which is why its version number, 140.16.0 here, shows many minor updates to the same base version. For an IT department this predictability is valuable: extensions, internal web apps and policies can be tested once and then relied on, without surprises every few weeks. Schools, libraries and companies with managed computers are the typical users. For an individual, ESR also makes sense if you dislike interface changes or run a specialised setup that must stay the same. The trade-off is that you receive new features later than everyone else, so if you enjoy trying new things, regular Firefox is the better fit.

Installation

1. Download the installer from Mozilla's Firefox for Windows page, choosing the ESR edition.
2. Run it, or deploy it with your organisation's software management tools.
3. Configure policies if you manage several computers.
4. Keep automatic updates on so security fixes arrive promptly.

Mozilla describes the current ESR line in its latest ESR notes, and all changes are listed in the Firefox release notes.

Planning upgrades

Each ESR line is eventually replaced by a newer one, and Mozilla overlaps the old and new lines for a while so organisations can test before switching. Put the change in your calendar, test your extensions and internal web applications on the new line during that overlap, and move everyone over before the old line stops receiving fixes. Home users who chose ESR simply need to accept the upgrade when it is offered.

Security

ESR is not an "old" browser: it receives the same security fixes as regular Firefox. Problems arise only when updates are switched off, so do not block them. Download Firefox only from mozilla.org.

Pros and cons

• Pro: stable feature set for long periods.
• Pro: regular security updates.
• Pro: free and open source.
• Con: new features arrive later.
• Con: mainly aimed at organisations.

Alternatives

Our listings include regular Mozilla Firefox and its portable edition, and Google Chrome, Microsoft Edge and Waterfox, other browsers for Windows.