This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Avatar for Username

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

This thread was archived. Please ask a new question if you need help.

Update or migration. 64 bit or 32 bit?

  • 3 replies
  • 54 have this problem
  • 8 views
  • Last reply by xusefab

xusefab
xusefab
more options

I read in the news that Firefox will be updated to 64 bit on version 41.

I already have Firefox 41, so I have many questions:

1- How do I know if I have 32 or 64 bit? Note: This question is already on the database, but the answers are useless, because the question was made when only there was an official 32 bit version, so the answer was that there was no 64 bit version.

2- Is or will be the 32 bit version automatically updated to 64 bit?

3- Is possible to run both versions? How to set the default one?

I read in the news that Firefox will be updated to 64 bit on version 41. I already have Firefox 41, so I have many questions: 1- How do I know if I have 32 or 64 bit? Note: This question is already on the database, but the answers are useless, because the question was made when only there was an official 32 bit version, so the answer was that there was no 64 bit version. 2- Is or will be the 32 bit version automatically updated to 64 bit? 3- Is possible to run both versions? How to set the default one?

All Replies (3)

jscher2000 - Support Volunteer
jscher2000 - Support Volunteer
  • Top 25 Contributor
more options

Firefox 41 for Windows is 32-bit only. A future version will have both 32-bit and 64-bit releases.

I have no idea what the upgrade path would be if you want to go to 64-bit, or how easy it will be to have them coexist.

Be aware that the only plugin that's going to work in the initial 64-bit release is Flash. If you use sites that need Silverlight, Java, or another plugin, you'll need to stick with 32-bit Firefox until the other plugins are supported in 64-bit.

James
James
  • Moderator
  • Top 10 Contributor
more options

Firefox 42.0 is the current target of maybe having Win64 builds. It can still change as they decided weeks before Firefox 41.0 Release to move Win64 to 42.0 at time due to sandbox issues.

Firefox 41.0 for Windows from mozilla.org is 32-bit only and your useragent has WOW64 which means it is a 32-bit application on 64-bit Windows. Mozilla/5.0 (Windows NT 6.1; WOW64; rv:41.0) Gecko/20100101 Firefox/41.0

2. The 32-bit Firefox on Windows will not get a update to 64-bit (WIn64) when it is out on Release channel but to 32-bit Releases.

Note that for Win64 Firefox one needs 64-bit Windows 7, 8 or 10 to run Win64 Firefox. The 64-bit WinXP, Vista and servers users can still run the 32-bit Firefox Releases.

There was talk of a stub installer for Windows that will download the appropriate 32-bit or 64-bit version based on what Windows you have.

The Win64 Firefox for Release will be low key initially as it will not be listed on www.mozilla.org or even on the www.mozilla.org/firefox/all page as was planned earlier on. It will be on say ftp.mozilla.org then.

64-bit Firefox is not new in that there has been 64-bit Firefox Releases since Fx 4.0 on Mac OSX and Linux both because it was needed and easier. Win64 Firefox was not needed for Firefox to run on 64-bit Windows and there has been hurdles to get to Release stage as just build WIn64 Firefox is not enough.

Modified by James

xusefab
xusefab Question owner
more options

James said

64-bit Firefox is not new in that there has been 64-bit Firefox Releases since Fx 4.0 on Mac OSX and Linux both because it was needed and easier. Win64 Firefox was not needed for Firefox to run on 64-bit Windows and there has been hurdles to get to Release stage as just build WIn64 Firefox is not enough.

Thanks for your answer.

I disagree on which 64 bit Firefox is not needed on Windows, since some pages crash due to the use of more than 1 Gb of RAM. Example, opening more than a dozen of tabs with Google Street View may cause tabs crashes on 32 bit Firefox. It does not crashes on 64 bit Firefox Nightly for Windows.