Using custom fonts
General
We recommend you to consider using system fonts on your store, because system fonts are already installed on a user's computer. Using system fonts avoids downloading new fonts to your customer's computer, which can negatively impact your store's loading speed. The font that displays on your customer's computer depends on their operating system.
Learn more about system fonts in Shopify's documentation.
See the list of system and other fonts you can found free in all Shopify stores.
How to use custom fonts
If you need to add custom font to the theme outside the fonts that Shopify offers