How can i get the available languages in a font?

[isaacfink]

I have a project that relies heavily on custom fonts and I need to be able to tell if a font is in a certain language, how can I do that?

[Connum]

You can get the avaialble scripts in a font from the gsub table:

font.tables.gsub.scripts.map(o => o.tag)

e.g. running this in the console of the demo page at https://opentype.js.org/
will result in the output

['DFLT', 'cyrl', 'grek', 'latn']

[vinuel]

Checking the language support of a font is not trivial and nothing that opentype.je would do on it's own. You could collect all unicode encoded characters in the font and check it with a database of languages. I've made it here, and also wrote some lines about it in the About section.