Whether or not you’re a seasoned designer, choosing a UI font can be a daunting task. As of writing this, Google Fonts alone has 997 families. You might think picking a font is mostly an exercise in preferences, but there are less subjective criteria that you should always be on the lookout for.
- Does it have 2–3 usable weights with italics?
You’ll generally need a regular weight and a bold weight. Adding a medium or semibold weight into the mix will give you more flexibility for creating a variety of complex components. Whichever weights you choose, having italics for them is a valuable addition. - Does it look good on PCs?
Theoretically this should be does it look good on your target devices, but I’ve yet to find a font that looked good on Windows and poor on Macs… The important thing to remember is operating systems, browsers, and screen quality all affect how a font is rendered so preview your fonts on various devices. - Does it have the characters you need?
Depending on the languages you support, you’ll want to look for those character sets. But beyond that, if your users are in the UK, does the font include a pound sign in addition to dollars? What about Euros and yuan?Don’t forget to check for less common but useful characters like ellipses and basic math symbols. - Does it have appropriate numbers?
Tabular numbers are equal-width characters that are especially useful for comparing values in tables, hence their name. Proportional numbers vary in width and are more appropriate for displaying numbers next to text (for example, in an address). One or both may be required based on your needs. - What does it cost to license?
I won’t try to convince you to use a free Google Font or buy the latest font from Hoefler&Co, but cost is a constraint you’ll have to weigh. Something to consider when choosing a system font or a system font stack, is that usage outside of the native devices may not be permitted (for example, in advertisements or print).