In my Firefox (linux) I can change the page as A4 in File → Page Setup → Page Size. Doing this, I inform the browser to print my pages as A4, instead of the default of Letter. My printer doesn't have Letter paper size (it just exists in USA). If it forget to change the page size, I have to walk to it, press "change page size" to start printing it.

How do I set the default page size to A4 once and forever?

  • 2
    The solutions presented here do no work for me on Firefox 17 on Ubuntu Precise. Could you please update your question to trigger new answers?
    – JJD
    Dec 17, 2012 at 22:04

6 Answers 6


I had this same issue today and found this post after searching Google. I fixed it in basically the same way as Android Eve laid out, just using the print.print_paper_name setting instead and using iso_a4 as the value.

So the long version, that's:

  1. In the address bar, type about:config.
  2. Enter print.print_paper_name in the filter box and press Enter.
  3. Double-click the entry named print.print_paper_name.
  4. Enter iso_a4 in the dialog box and press OK.
  5. Notice that it now works fine, and upvote this response ;)
  • 1
    It works on Ubuntu 14.04. Huge fault on the side of ubuntu (et al) to not set Letter/Paper Size to Locale. Here in Europe we don't have US paper. In the US you have US paper. If I wanted to print with US paper I would have set my Linux locale to US or move to the US altogether and buy my paper there.
    – user46445
    Jun 3, 2014 at 18:08

Check out this man page:

paperconfig - configure the system default paper size


paperconfig [ -v,--version ] [ -h,--help ] [ -p, --paper papername | --force ]


paperconfig sets the system (or default) paper to be used by tools using the papersize >file. It can either ask interactively for the paper to use or be called non-interactively >by scripts.

When the paper size has been changed, paperconfig notifies other packages of the change >by running the scripts in the /etc/libpaper.d directory.


Print the version of paperconfig and exit.
Print help about usage and exit.
-p, --paper papername
Use papername if possible. If papername is not a valid paper, print an error message and exit.
Force interactive selection of the system paper even if the actual paper is a valid one.


PAPERCONF Full path to a file containing the paper size to use; this file will be rewritten with the system paper size.


Contains the name of the system-wide default paper size to be used if the PAPERSIZE variable is not set.

Directory of scripts to run after the paper size has been changed. This package puts no scripts here, but other packages may.

So you would run paperconfig -p a4 in the commandline.

  • I don't have paperconfig in my old CentOs 5.2 (it is a corporate machine)
    – neves
    Sep 3, 2010 at 21:51
  • If there's a /etc/papersize file in your computer, you can change the contents to a4 and it'll have the same effect.
    – digitxp
    Sep 3, 2010 at 22:06
  • 3
    Thanks for that from me as well - unfortunately, I just checked /etc/papersize - and it says a4 there; however, firefox still insist on letter (damn it...)
    – sdaau
    Jun 13, 2012 at 8:48
  • Agree with sdaau FFox does seem to ignore /etc/papersize. Time will tell whatother programs do ignore that setting too. It's times like these that makes it totally obvious why everybody uses Windows and Mac. It's completely inferable that nobody in his right mind would want to fiddle around with endless text files if the only thing he wants to do is to print with his printer that he bought in a country where there is no us_letterhead available anywhere, countrywide.
    – user46445
    Jun 3, 2014 at 18:10

Make sure /etc/papersize has a4 in it, for some reason it tend to be letter.

sudo sh -c "echo 'a4' > /etc/papersize"

Then set LC_PAPER to your locale, in my case it sweden.

sudo sh -c "echo 'export LC_PAPER="sv_SE.utf8"'>> .profile"

All locales but en_US should work since US is the only one that uses letter, the rest of the world uses A4.

  • Putting a4 in /etc/papersize definitely does not work for Firefox. I also have LC_PAPER="en_GB.utf8" after a locale-gen and reboot, and still no go.
    – l0b0
    Aug 2, 2015 at 21:24

Dave's answer didn't work for me in Firefox 5 on Linux, it seems Firefox now stores separate settings for each printer it sees. If you search for print_paper_name in about:config you will see several similar settings for each printer e.g. "printer.printer_Samsung_ML-2010.print_paper_name". Set all of them to iso_a4 and join the civilised world of standardised paper sizes.

  • Many thanks, @LukeMcCarthy - that seems to have done the trick for me; indeed there were a ton of options that I saw on my Firefox, were set to na_letter; changed those to iso_a4. and even without a restart, the default page size changed (for the printer I wanted to use, which for me was printer_PDF.print_paper_name). Thanks again - cheers!
    – sdaau
    Jun 13, 2012 at 8:53
  • .... however, the crappiest part about it is that now I get A4 selected by default in the "Print to File" options - but that STILL does not SET the goddamn page size; so now I have go back through that options window, and RECLICK page size to something OTHER than A4, and then BACK AGAIN to A4, so it understands it is goddamn A4 (always use pdfinfo on those printouts).... Goddamn it!
    – sdaau
    Jun 13, 2012 at 9:07
  1. In the address bar, type "about:config".
  2. Enter "print.postscript.paper_size" in the filter box and press Enter.
  3. Double-click the entry named "print.postscript.paper_size".
  4. Enter "paper" in the dialog box and press OK.
  • I've already had made this configuration, but Firefox insists to send Letter pages :-(
    – neves
    Sep 3, 2010 at 21:49
  • On Windows, Firefox doesn't even have a paper size option and just follows the default setting provided by the printer driver. Maybe you have to change the paper tray settings through your printer driver's interface. Not sure if there's a centralized place to do this on Linux... If you're using Gnome, maybe you can try System -> Administration -> Printing
    – billc.cn
    Aug 9, 2011 at 0:36

Try going to Page Setup and disabling the Shrink to fit Page Width option. This was the only thing that worked for me after changing the config options didn’t. (For changing from default paper size 'Letter' to 'A4'.)

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