The only reason someone would stick with a 32-bit browser is for performance reasons. 64-bit applications have a larger memory footprint from all the 64-bit cod

The only reason someone would stick with a 32-bit browser is for performance reasons. 64-bit applications have a larger memory footprint from all the 64-bit code and pointers. We didn't see much performance difference when testing 2 GB Windows machines hands on, but Firefox telemetry analysis showed that user retention and crash rates were worse for users with <= 2GB than for > 2GB. Only about 1% of Firefox Windows users have < 2GB and about 5% have exactly 2GB. Users with <= 2GB can still install 64-bit Firefox if they really want to by downloading the 64-bit full installer instead of the "stub installer" (a tiny downloader that detects 32- and 64-bit OS and downloads the appropriate full installer). Likewise users with > 2GB can download the 32-bit full installer, too. We wanted the Firefox installer's default to provide the best user experience, but still give users the option to run the (32- or 64-bit) application of their choice. For comparison, 64-bit Chrome's minimum memory requirement is >= 4GB.