Issue Summary

HEIC images not rendered when uploaded through Confluence iOS app

Version: The images captured on your iPhone 17 Pro Max are saved in HEIC format 

Safari users are unaffected as Apple added native HEIC support in Safari 17.

•  The same Confluence page renders images correctly in Safari but shows "Preview Unavailable" in Chrome
•  Download still works (the file is intact), but inline preview and the attachment viewer both fail
•  Renaming the file extension (e.g. .heic → .png) does not resolve the issue as the underlying binary data remains HEIC-encoded

Steps to Reproduce

 1.  Take a photo on an iPhone (iOS 11 or later, default camera settings = "High Efficiency")
 2.  Transfer the photo to a computer (e.g. via OneDrive, iCloud, AirDrop)
 3.  Upload the .heic file to a Confluence Cloud page as an attachment or inline image
 4.  View the Confluence page in Google Chrome

Expected Results

Image renders inline

Actual Results

Image shows "Preview Unavailable" — clicking it says "We can't preview this file. You'll have to download the file to view it."

Workaround

Users must manually convert HEIC images to JPEG or PNG before uploading:

•  Mac: Open in Preview → File → Export → Save as JPEG/PNG
•  iPhone settings: Settings → Camera → Formats → Most Compatible (captures as JPEG going forward)
This is a significant friction point for iPhone users who share photos via Confluence.