Bug 259361

Summary: STP advertises support for JXL but can't decode them
Product: WebKit Reporter: Jon <jon>
Component: ImagesAssignee: Nobody <webkit-unassigned>
Status: RESOLVED DUPLICATE    
Severity: Normal CC: ap, sabouhallawa
Priority: P2    
Version: Safari Technology Preview   
Hardware: Mac (Apple Silicon)   
OS: macOS 13   
URL: https://cloudinary.com/blog/jpeg-xl-how-it-started-how-its-going
Attachments:
Description Flags
Screenshot of broken site. none

Description Jon 2023-07-20 09:50:32 PDT 
Created attachment 467079 [details]
Screenshot of broken site.

Starting with STP based on Safari 17, STP, even on Ventura, advertises support for JXL, both in requests and release notes. However, downloaded JXL files can't be displayed, leading to broken images on screen. For instance, the recent JXL article from Cloudinary (https://cloudinary.com/blog/jpeg-xl-how-it-started-how-its-going) supports JXL for almost all images but is broken in STP (on Ventura). If Ventura can't support JXL then STP shouldn't advertise it. This is the accept header for the image request:  image/webp,image/avif,image/jxl,image/heic,image/heic-sequence,video/*;q=0.8,image/png,image/svg+xml,image/*;q=0.8,*/*;q=0.5
Comment 1 Alexey Proskuryakov 2023-07-20 13:13:47 PDT 
Thank you for the report. This is a bug, STP should be able to display JPEG XL.

*** This bug has been marked as a duplicate of bug 258655 ***
Comment 2 Jon 2023-07-20 13:18:30 PDT 
Sorry for the dupe. Neither bugzilla nor Google search turn up that bug when searching for JPEG XL.
Comment 3 Alexey Proskuryakov 2023-07-20 13:27:06 PDT 
No problem. For completeness, Safari 17 beta 3 should support JPEG XL on both macOS Ventura and macOS Monterey, too. Which is indeed the case on Monterey in my testing (I didn't try Ventura).