Mozilla started to upgrade Firefox 32-bit installations on Windows to the 64-bit version of the web browser when it released Firefox 56 in late 2017 to the public.
While stable 64-bit versions of the browser have been available for Linux and Mac OS X for a long time, the same could not be said for the Firefox 64-bit version for Windows in 2017 and earlier.
While Mozilla offered as 64-bit development version for those in the know, a stable version was not provided for a long time
Mozilla started to release Firefox 64-bit for Windows in December 2015 to the release channel. This was first an optional download that users had to seek out, but has since then been made the default.
The organization revealed in August 2016 how it planned to make Firefox 64-bit on Windows the default for compatible systems, and migrate the 32-bit population on 64-bit architecture to the 64-bit version of the browser.
The plan back then involved integrating the 64-bit version in the Firefox stub installer, making it the default in early 2017 in that installer, and shipping Firefox 64-bit as the default later that year.
Starting with Firefox 55, which was released in August 2017, 64-bit Firefox were the default option on Windows. This was only the case however if the Windows device supported 64-bit and had at least 2 Gigabytes of memory.
Migration from 32-bt versions of Firefox to 64-bit on Windows started with the release of Firefox 56. in September 2017.
Starting with Firefox 56, Mozilla started to upgrade Firefox 32-bit installations on 64-bit versions of Windows to 64-bit versions of Mozilla Firefox.
The same limitation -- a minimum of 2 Gigabytes of RAM and at least Windows 7 -- apply.
The main reason why Mozilla decided to migrate Firefox users on Windows to 64-bit versions is that running a 64-bit copy of Firefox decreases the out-of-memory crash rate and improves security.
Downside is that 64-bit versions of Firefox use more memory than 32-bit versions of the web browser.
Mozilla published some stats that highlight these improvements and changes:
Ghacks is a technology news blog that was founded in 2005 by Martin Brinkmann. It has since then become one of the most popular tech news sites on the Internet with five authors and regular contributions from freelance writers.