Experimental Feature: Can be enabled via Firefox Labs
Before we begin, I recommend reading:
Great news for JPEG-XL supporters! While Apple has championed the format for a while now—both natively and across its Safari browser, Firefox is officially joining the ranks. They recently introduced JPEG-XL support under their experimental features section, Firefox Labs.
(Note: Previously, Firefox only enabled JPEG-XL by default within its experimental Nightly builds.)

As the snapshots below demonstrate, JXL images are now rendering successfully. Given this progress, it is highly likely that an upcoming stable release of Firefox will have JXL support enabled by default.
