The photo your iPhone won't show anyone

An iPhone shoots HEIC by default. Safari renders it. Chrome doesn't. Firefox doesn't. So a photo straight off the phone, attached to a post and published, is a photo most of your readers will never see.

The old behaviour was the worst possible one: the file went in, the build couldn't measure it, and the image quietly vanished from the page — taking its caption with it. No error. Just a post with a hole where a photo was.

Refused, with the command you need

Attaching a HEIC now stops the save and prints the exact conversion command for the machine you're standing at:

sips -s format jpeg photo.heic --out photo.jpg      # macOS
heif-convert photo.heic photo.jpg                    # Linux

Your file stays exactly where it was, in incoming/. Nothing is deleted, nothing is guessed at. You convert it and carry on.

Or converted, if you ask

Set media.convert_heic: true and the engine converts it for you, using whichever tool it finds — sips, heif-convert, magick, vips. If it finds none, it falls back to the refusal above rather than pretending.

That's off by default on purpose. Converting means the file on your site isn't the file you handed over, and that should be a decision you made, not a thing that happened to you.

Detection is by content

Renaming photo.heic to photo.jpg doesn't get it past the check — the engine reads what the file actually is, not what it's called. Phones and export tools mislabel files often enough that trusting the extension would just move the silent failure somewhere less obvious.

The rule underneath

An image must never disappear quietly. If the engine can't handle a file, it says so, names the file, and leaves it where it is. A build that drops a photo and finishes with a cheerful summary has lied to you, and you'll find out months later when someone mentions the empty space.

(If you'd rather sidestep all of this: Settings → Camera → Formats → Most Compatible makes the phone shoot JPEG.)