Users who download Firefox using a 64-bit Windows version, now automatically receive the 64-bit version of the browser, which is safer than the 32-bit version, Mozilla today announced. The 64-bit version has all kinds of security advantages, according to the browser developer.
E.g the security measure Address Space Layout Randomisation (ASLR) works much better thanks to the additional 32-bits. ASLR makes it harder for attackers to predict in which memory areas applications are loaded. This should make it harder to exploit vulnerabilities in e.g. the browser. The 64-bit also makes the browser more stable. It crashes less than the 32-bit version according to numbers collected by Mozilla. The 64-bit browser on systems with 4GB or more crashes 39% less.
Mozilla plans to automatically migrate all users on a 32-bit version of Firefox on a 64-bit version of Windows, to a 64-bit version of the browser. Users who don’t to wait for that to happen can download the 64-bit version of the browser from the Mozilla website.
Users who want to continue to work with a 32-bit version of Firefox, can install the 32-bit version again after they’ve been automatically upgraded to the 64-bit version.