CFF2 variable fonts appear lighter on Chrome than Firefox and Safari

[wecessary]

Hi everyone, web developer here so apologies if I use the wrong typographic terms. Also thank you for such a great open source typeface!

As title says, when using otf and woff2 variable fonts, the text looks lighter on Chrome, at the same font weights. This not only happens on my own website, but also on Source Serif demo page https://adobe-fonts.github.io/source-serif/. Please see screen shots below.

Note: the issue does not appear when using ttf variable downloaded from Google Font. I discovered this because I notice that the text on Google font page https://fonts.google.com/specimen/Source+Serif+4 looks the same across broswers.

My website:
On Chrome, font weight 400

On Safari, font weight 400

Source Serif demo site:
On Chrome, font weight at extra light

On Safari, font weight at extra light

[punchcutter]

Probably the same as adobe-fonts/source-han-serif#182

[frankrolf]

Hi @wecessary, thanks for your report.

Every browser/OS combination has slight differences in rasterization, which also may depend on a user’s settings and preference. This is most obvious in the rendering of lighter weights.

In my case (macOS 14.5), I see the following:

Chrome renders the ExtraLight VF a bit lighter than Safari in light mode, and a bit darker in dark mode.
Unfortunately, I don’t think this is this something that can be influenced by the font, it’s up to the rasterizer to interpret the font data.

[frankrolf]

FWIW, the 4.005 release contains both TTF and CFF2 variable fonts – you are free to pick whichever you like :-)