Ubuntu – Render webpages in Ubuntu font

The problem is not anti-aliasing - all of your examples show the text is anti-aliased fine.

The difference is in an aspect of font rendering called "hinting" - the top Ubuntu Mono example shows a strong hinting, whereas the bottom Ubuntu Mono example shows a smoother hinting. Hinting deforms the letter shapes to better align to the pixel grid and give a more crisp appearance.

Whether you like one or the other is a matter of personal preference. The top one is certainly very clear to read but at the expense of deforming the letter shapes.

The Java environment will be using its own font renderer rather than your global settings, hence the difference.

There are various fixes for this described in this link at stackoverflow.com:

https://stackoverflow.com/questions/17510099/ugly-fonts-in-java-applications-on-ubuntu

This one looks pretty simple (I have not tested this):

Try adding

export _JAVA_OPTIONS='-Dawt.useSystemAAFontSettings=gasp'

to your ~/.bashrc

But the chosen solution is more complex.

There was a bug in the fontconfig package (I reported the bug, which has since been fixed in fonts-noto-cjk - 1:1.004+repack2-1~ubuntu1) which somehow let Chrome believe that "thin" is the correct weight to use. I removed the package and downloaded NotoSansCJK directly from Google, which contains fonts of different weights in separate files. After installing the fonts manually this issue seems to be fixed, and Chrome is able to render CJK correctly even though my default font is still unchanged (Liberation Sans).