Note:
Loading priorities are
not
guaranteed to be consistent cross-browser so use this knowledge wisely and measure when unsure. Ideally, aim to delivery a great experience to the
widest
number of users possible.
If you’re a web developer wondering where you can see the “Loading Priority”, Chrome DevTools has an optional “Priority” column available in the Network panel. Right-click the column headers and you can switch it on:
The
summary
table of priorities is still correct as of February 2019. I would personally love to get a better understanding of loading priorities in other browsers too. Hopefully this overview is useful to someone out there!
Thanks to Kouhei, Dom Faralino, Pat Meenan, Kenji Baheux and Yoav Weiss for their contributions helping better explain Chrome’s network stack.
Further reading