Incremental Font Transfer

Incremental Font Transfer Demo

This demonstrates the use of the patch subset incremental transfer protocol to incrementaly load a COLRv1 font.

Instructions:
  • You must have the COLR v1 flag enabled in chrome. Open chrome://flags to enable it.
  • Next/Previous will switch between text samples. Switching to a new sample will use IFT to load any additional font data needed for it.
  • If "Also load fonts via unicode range" is selected then fonts will be loaded via the Google Fonts API (using unicode range) in parallel to incremental font transfer.
  • Disable caching (via dev console) or force refresh the page (ctrl+shift+r) before starting. If caching is enabled the unicode range font loading may be served from the cache which will make the bytes transferred incorrect.
  • If unicode range loading is enabled you can switch the displayed text sample between the two methods using the "Show unicode range" button.
Unicode range

Incremental font transferred:
Unicode range transferred: