Skip to content
CarbonlessBeta

Guidelines · WSG 2.11

Use optimized web typography

Fonts are render-blocking by default and easy to over-ship: four weights of two families is common, and most of it is never seen on the page that loaded it.

How to satisfy it

  • Prefer a system font stack where the design allows it: zero bytes, instant render.
  • Subset custom fonts to the characters the site actually uses.
  • Ship WOFF2 only. Older formats are dead weight for browsers that all support WOFF2.
  • Use font-display: swap so text is readable before the font arrives.

Measured pages failing this guideline

From the 60 most recently measured pages. Each links to its full report.

This page explains how Carbonless applies WSG 2.11. The guideline itself is published by the W3C Sustainable Web Design Community Group: Web Sustainability Guidelines.