On the desktop, Preview app (and lots of others) will open and export as ...
On the phone (Apple, sometimes you bewilder me), You can convert in Files, not Photos. 1. Save a photo to FILES from camera roll or web (This works with webp, as well) 2. click and hold the THUMBNAIL, do not open the image. 3. Quick Actions -- Convert image. 4. You can now "save" the image (open, do not click and hold) to your camera roll.
This is BONKERS
As others have noted, "There's an app to do it".
Worst for me in daily life, when you get info on an image (in the camera roll, pull up on the image) WEBP does not even show as a file type. HEIC does.
ios 18, not 26.
[0] https://toolsfairy.com/tools/image-test/sample-heic-files
https://caniuse.com/?search=HEIC
I mostly am a DSLR photographer but for the occasional iPhone shot
https://mastodon.social/@UP8/115740936297822037
I use Photoshop. (Where's Cindy when I need her?)
That said, when I move photos from my phone to by desktop via Signal; somewhere along the way it gets converted to JPEG so it's not a concern.
Settings -> Camera -> Formats -> Most Compatible
Settings → Apps -> Photos → Transfer to Mac or PC → Automatic (convert to jpg)
or
In "Shortcuts" app - select photo, convert to jpeg, save file:
Use it to convert customer images sent from iphones.
