Although there is no official documentation on this, here are my observations:
Testing Method
- Tested exclusively with Google Chrome version 61.0.3163.100 (Official version) (64 bits)
- Utilized Fast & Slow 3G throttling in the developer tools.
What I Examined
I had a stylesheet that imported custom fonts and applied them to the text.
Before:
The text using the custom font remained invisible until it fully loaded and then appeared on the page.
After/Result:
Therefore, the outcome was that the text became visible immediately as the page started rendering, initially using the fallback font, and then switching to the custom font after some time.
It appears that Google Chrome supports defer on <link>
tags, even if this feature is not publicly documented...