How to enable stylistic sets

Stylistic sets allow you to access additional, optional parts of the font on a per-feature basis. In Fira Code, they allow you to enable/disable alternative character variants.

Fira Code v2 supports these stylistic sets:

You can enable stylistic sets only if your editor supports it.

Atom

Go to Atom -> Stylesheet, add:

atom-text-editor {
  font-feature-settings: "ss01", "ss02", "ss03", "ss04", "ss05", "ss06", "zero", "onum";
}

Sublime Text

Go to Sublime Text -> Preferences -> Settings, add:

"font_options": ["ss01", "ss02", "ss03", "ss04", "ss05", "ss06", "ss19", "ss20"]

(for now Sublime Text does not allow you to specify zero and onum features, but they are repeated as ss19 and ss20.

VS Code

Via editing electron-browser/index.html, see https://marketplace.visualstudio.com/items?itemName=be5invis.vscode-custom-css

In a recent patch of VS Code (microsoft/vscode#82153), it will be able to define

"editor.fontLigatures": "'ss01', 'ss02', 'ss03', 'ss04', 'ss05', 'ss06', 'zero', 'onum'"

in settings.json without hacking the editor's CSS. It is not clear that this feature will be merged into any future releases of VS Code.

VS Code (soon)

https://github.com/microsoft/vscode/issues/10435#issuecomment-545513026

CSS

.monaco-editor {
  font-feature-settings: "ss01", "ss02", "ss03", "ss04", "ss05", "ss06", "zero", "onum";
}

Some Apple apps

Adobe apps, MS Word etc

https://www.macworld.com/article/3052388/how-to-access-advanced-opentype-features-in-a-variety-of-mac-apps.html

Baking in stylistic sets into the font file

This might be an option if your editor does not let you choose stylistic sets on the fly https://github.com/twardoch/fonttools-utils/tree/master/pyftfeatfreeze