Theme Font & Size Changer

Theme Font & Size Changer Project Image

Congratulations! Theme Font & Size Changer installed successfully. You can right now start using your new add-on.


Theme Font & Size Changer is a simple browser tool that lets you change the font size and font family of Firefox. It is especially valuable tool for visually impaired people and wide screen users.

There are three places that you can manage the global font size and font family of Firefox via Theme Font & Size Changer. Add-on Bar icon, toolbar button and Tools menu option. All font size and font family changes are instantly applied and they are saved permanently and through sessions.

Different from add-ons that enlarge and reduce text on web pages, Theme Font & Size Changer changes the font size and font family in all windows, menus, toolbars, etc within Firefox itself.

It was initially created to be an accessibility aid for persons with visual impairments and for those without perfect eyesight, but it’s also useful for Firefox users with high monitor resolution settings and wide screens.

While Theme Font & Size Changer was written to be used with Firefox default theme, it does work with other non-default themes, but you may come across issues where some elements within Firefox retain the (non-default) font size setting that the theme developer chose for their theme.

There are three places that you can manage the global font size and font family of Firefox via Theme Font & Size Changer:

• Add-on Bar Button: Click on the Theme Font & Size Changer button to open up Theme Font & Size Changer settings panel.

NOTE: Add-on Bar resides at the bottom of the Firefox window. Add-on Bar is the old status-bar. If Add-on Bar is not visible, you should activate it. To do so, choose View menu from Firefox Menu Bar and hover over the Toolbars option and click on the Add-on Bar option if there is no tick. If you are Windows 7 user, you should click on the orange Firefox button at the top of the window and hover over the Options and click on the Add-on Bar option if there is no tick.

• Tools Option: Choose Tools menu from Firefox Menu Bar and click on the Theme Font & Size Changer option. It will open up Theme Font & Size Changer settings panel.

• Toolbar Button: It is optional so it is not visible as default. If you want to place a Toolbar Button, right click on a toolbar button like Home Button, then choose Customise option. A window will pop up. Find the Theme Font & Size Changer button, then click and drag the Theme Font & Size Changer button in the toolbar of your choice and drop the button. Clicking on this Theme Font & Size Changer button will open up Theme Font & Size Changer settings panel.

In Theme Font & Size Changer settings panel, Font section provides fonts currently installed on your operating system. With this option set, you will be able to fine tune your font family of Firefox theme.

In Size section, simply select a font size value (from 6 to 80 pixels) and the changes will be applied instantly and globally.

A Normal (default) value is also provided as well as an indicator next to the currently applied font size and font family setting so that you can reset to the default Firefox values.


Known Issues:
Please keep in mind that this extension was designed for use with default theme of Firefox and the fact that it works with non-default ones is more of a bonus than the primary goal and function of it.

Compatibility issues found when tested with 32 Firefox themes were minor overall, but a few were major, while others had no compatibility issues at all.

Any compatibility issues will mostly be dependent on the theme (or extension) developer’s CSS value choices for any given element.

The font size in some elements in non-default themes remains unchanged.

For example and through testing, the font size of tab text was unchanged by Theme Font & Size Changer (in some themes).

Repeating backgrounds:
With some non-default themes you may encounter repeating backgrounds (on toolbars, etc) when the font size is increased. Increasing the font size also increases the height of other elements (like toolbars) and so if specific CSS properties are not set to prevent backgrounds from repeating, then a background will repeat itself which you may find to be undesirable.

Text bleeding out of elements or being cut off:
You may notice this in some themes such as on dialog buttons, drop down menus, and tabs.

No known compatibility issues with the following themes:

NASA Night Launch
Kempelton
Kempelton Large
Qute
Mostly Crystal
Silvermel
Walnut for Firefox
Ambient Fox Xyan
Themes by Aaron Spuler

There are no known compatibility issues with Personas skins.

Special thanks to Ken Saunders for the priceless contribution and testing efforts.

If you find the application useful please support my development efforts.


77 Responses to “Theme Font & Size Changer”
  1. AAB says:

    THANK YOU!!! I have a degenerative eye disease for which there is no cure. It makes it very difficult to see small print on my widescreen laptop. This is a life saver for me. Donation is on the way. THANK YOU!

  2. Frances says:

    This is a wonderful add-on to use. You can adjust to what size and style you like. I prefer the Arial Bold print size 16

  3. Helene says:

    Thank you so much for this. I had stopped using Firefox because of the small font and now I can go back to using it!

  4. Steve Maxwell says:

    Amazing! This is the first time I’ve had an addon for Firefox to change font sizes in the toolbar-now I can actually read the Fire.FM thing without an electron microscope-Thank You!

  5. Alex says:

    I LOVE working with Fonts.. Another reason to Love mozilla.. Thanks for this great app!

  6. Thank you, my husband is blind in one eye and this will make his laptop use so much better

  7. Rehan says:

    It’s a Amazing! This is the first time I’ve had an addon for Firefox to change font sizes in the toolbar-now I can actually read the Fire.FM thing without an electron microscope. I LOVE working with Fonts..-Thank You!

  8. roel despi says:

    Thank you… for this very nice add on You can adjust to what size and style you like. I prefer the Arial Bold print size 16

  9. Rose says:

    I have used this program before on my older computer and love it! Now I have newer up to date laptop and I am so thankful that this gizmo is still being offer for us old middle age poor brats with bad glasses. Thank You!

  10. Thank you. I am a diabetic and sometimes my vision gets blurry or its just hard to see, like everything is too far away. I am on the internet everyday. This really saved me many headaches. Thank You.

  11. sureñitha says:

    Thank you so much for this. I had stopped using Firefox because of the small font and now I can go back to using it!

  12. THANK YOU!!! I have a degenerative eye disease for which there is no cure. It makes it very difficult to see small print on my widescreen laptop. This is a life saver for me. Donation is on the way. THANK YOU

  13. I think it’s just great… it makes some of the prettier personas that didn’t have the right coloring to maximize it to the best , is not fixable. ! TYVM

  14. Flossie Dale says:

    Hello,

    This looks like a handy tool.

    However, I’m having a few problems with it…

    I’m running Firefox version 3.6.22 (yes, I know it’s really old – but I’m stuck with this version at work) on Windows 7.

    Every time I click on what of the functions (for instance “Change Font”) it does work (e.g. the font changes) but I get a [Javascript Application] error popping up which says “TypeError: window.opener.TabsInTitlebar is undefined”.

    Any idea why it’s happening?

    Many thanks,
    Flossie

  15. Baris Derin says:

    Hello Flossie,

    It is in our bug fix road map, hope we can fix it soon.

  16. escot says:

    I too am delighted by this add-on. (though I am amazed that T-bird is now in version 6, and it never dawned on anyone that size of text in panes might matter!?? Come on folks, what century are we in?) Yet mega thanks for this add on…. I’m applying it via T-bird version 6.02. (on Win 7 machine) Seemed to install ok, but like Flossie below, every time I make a size change, I get this error: “TypeError: window.opener.TabsInTitlebar is undefined “

  17. J Me says:

    This is one of my ‘can’t do without’ Add-Ons. I look forward to an update for Thunderbird 7.

  18. SvenH says:

    Thanks Baris, I guess you made an update as the extension now works in Thunderbird 7. Thanks again.

  19. Jennifer Cluse says:

    Thank you very much, Baris, for your focus in developing this assistive tool.
    I haven’t even installed it yet, but being involved in assisting some sight impared people, (and expecting to be-there myself one day, as will 1 in 4) the benefit of this tool is self evident.
    Again, thanks!

    Cheers

    Jen Cluse
    Brisbane Oz

  20. Karen says:

    Thank you so much!! I was getting headaches from straining my eyes on tiny fonts. Bless you. ;)