I am using Calibre 2.49 on an Ubuntu machine and I noticed that in eBook viewer preferences, whatever font I set, calibre just displays the default font. I tried this on many ePub books. Here is a screenshot of my preferences dialog: enter image description here

I tried reloading book, exiting calibre, but it didn't work.(The font size setting works fine, though).

  • 1
    Remove embedded fonts does nothing.... for ANY epub book I've ever tried to convert. Why do all of these suggestions work for other people but not me ?????. Hilarious but frustrating because so many books I DL have these nasty, italicized, scripted fonts that I can't change and so I just delete them instead of reading them. I'd be happy to hire someone to fix this for me but don't know how to find that person. Shit.
    – Rick
    Aug 24, 2020 at 20:34

5 Answers 5


If the ebook contains some definitions about the fonts to use, it takes the precedence over the default Calibre settings.

Maybe the ebook you are reading has some CSS rules that define the default font to use on the book itself (and probably the ebook even includes the said fonts).

You can try this yourself: this version of Treasure Island from MobileRead include font definitions for the text, and it keep using it even if you change the standard one on the Calibre settings.
This version of Dr Jekyll and Mr Hyde, always from MobileRead, doesn't contain any font definition in its CSS and it uses the default one as defined by Calibre.

It just works like that. You should look at the default settings in Calibre as a fall-back in case the book doesn't provide any information in this sense.

If you really want to change the font used during reading, you should edit the CSS file(s) inside the epub and remove all references to any defined font.

Calibre also has a plugin called Modify Epub that, amongst other things, let you remove internal font settings from an epub file. Once you have installed it, select the epub files you want to modify this way, click the Modify Epub icon on the toolbar, and select the corresponding option, as shown on the picture. It will remove both the custom fonts inside the book and the references to them on the CSS.

Please note that if you process many ebooks at once it may require some time to complete this task.

enter image description here

  • The Modify Epub plugin was super helpful. Thanks.
    – Ryan
    Sep 21, 2018 at 0:06

Some EPUBs may have font information specified directly as inline CSS. It will have preference over more generic options. In that case you can convert eBook and strip font-related styling:

enter image description here

  • that works for embedded font colors too, by checking the "Colors" at the right
    – cipricus
    Mar 15, 2020 at 20:37

The most canonical way to set styles globally is to set them in the Styles section.

The basic set of styles for changing fonts are simply:

body {
font-family: Crimson;
h1, h2, h3, h4, h5, h6 {
  1. Open a book
  2. Right click

The book options menu

  1. Go to the Styles section

Subsequent menu

  1. Set styles The Styles Page

A simple solution is go to Preference - Styles

Put this piece of code in it

* {
  font-family: "The font you want" !important;

It's not a beautiful solution but easily works. So you can take your time to focus on the book you read.


A workaround is to convert to .azw3. Then, font size changes work as expected.

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