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 Large
Mostly Crystal
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. LR says:

    Thank you so much for this add-on. I have been looking for a way to increase the font size inside of the Groowe toolbar search box for later versions of FF. This does it!!

  2. Roger says:

    Ran into a problem with Thunderbird 9 and Theme Font & Size Changer 3.2. For some reason TB 9 moves the size handle all the way to the left and when it does, all info and anything else on the status bar goes with it. In other words the status bar icon isn’t anywhere to be found when this happens. thanks…

  3. Aaron says:

    Great tool. However, if you change font… it changes in the extensions box as well making the option at the bottom (color – bg color) disappear. I am also getting the error mentioned in an earlier comment. Thanks.

  4. onenrone says:

    You should pith this as an “Adaptive” and “Assistive” tool.

    Thank you,

  5. Butch32940 says:

    How do I increase the e-mail message. When I open an e-mail. it’s in the previous default font. Way too small to read.

  6. nile says:

    I use DownloadStatusBar extension alot

    This seems to stretch the text in it rather a lot, any way to exclude that plugin (which ahs it’s own text size management feature)

  7. Jayabalan says:

    Excellent add-on. Effort to produce this for Firefox browser much appreciated.At last no boring system fonts for FF browser.This will be useful to people who require clear and eye sensitive fonts for browsing (also dyslexic people) who can change the font with ease.Again thanks for the effort.Hoping to see more add-ons like these in the future.

  8. shinde Ranjit says:

    it’s very nice things to use as backgrounds themes and font . I am thankful to you add such nice themes and fonts for on Mozilla Firefox.

  9. Vic Murillo says:

    Thank for this tool. It makes it easy to read and work at my laptop. I have been looking for such a tool for a long time. Not everybody has 20/20 eyesight. Thanks !!!

  10. Tom Morrow says:

    Excellent! Works well with LavaFox V2. I greatly appreciate this add on. This should be integral,not an add on.

  11. Bonnie Marie Barry Nyholm says:

    This is so great….and I only have to change it when I need the font size to be different…and that is soooo easy! Thank You! Wish I had money to donate but I am on a fixed income! I Love Firefox! And to think….I was scared to try it….now I wouldn’t use anything else! God Bless You All!

  12. Doc says:

    Love the font and themes changer. It’s cool to be able to use any kind of font and them that you are comfortable with.

  13. Himanshu says:

    awesome add-on!
    works perfectly in thunderbird as well as firefox..thanks so much

  14. Chris says:

    Thank you for this excellent add-on! Coming from Ubuntu and Linux Mint where one is spoilt with crisp, clear fonts on Firefox and Thunderbird, I was very disappointed after I recently installed these apps on my new Mac mini. However, with the help of your add-on, FF and TB now look good on the Mac, too!

  15. Susan says:

    Hahhh! Wonderful with Halloween theme! Really added “atmosphere” Thank you so much. Customization Rocks!

  16. el mistical says:

    this is sweet it will help so many people with eye problems

  17. Windy says:

    Thanks very much for providing this plug-in, it is very help to improve my experience for surfing with FireFox.

  18. L.Kalla says:

    Thanks for this add-on. It’s perfect

  19. seagle says:

    Great, thanks!

  20. trisha says:

    i love this, thank you, its better than going to the toolbar and using the veiw,and zoom in and zoom out, thank you so much again