iPhone
Convert Camera Roll photos to WebP on iPhone
Safari is the app. There is no Shift listing in the App Store. Files stay on the phone.
HEIC first, then Shift
iPhone still stores many originals as HEIC. Shift will refuse those on purpose after reading the ftyp brand. Convert HEIC to JPG with HEIC Local (also in-browser), then open that JPG here for WebP or AVIF. If you already used “Most Compatible” in Camera settings, you likely have JPEG and can skip that hop.
Settings → Camera → Formats → Most Compatible writes JPEG into the roll. High Efficiency writes HEIC. Shift is a codec converter, not a HEIF decoder. The refusal is a sentence on the row, not a silent skip, so you know which files never entered the canvas.
Use Choose files, not drag-and-drop
iOS Safari’s drop target is unreliable. Tap Choose files, pick one or more photos, set WebP (default), set a max width of 1920 if the phone is old or the photos are 48 MP, then Convert. If AVIF encode is no on your iOS version, ignore AVIF. That badge is the truth for this device, not a broken feature flag.
You can pick from Camera Roll or from the Files app. iCloud photos that have not downloaded yet may arrive as tiny placeholders or fail the magic-byte check. Wait for the full photo, then convert. Live Photos: you get the still, not the motion pair.
Download and Share
After convert, Download tries the iOS Share sheet with a real File when canShare allows it. Save to Files, AirDrop, or Mail from there. If you cancel the sheet, nothing is uploaded anywhere because nothing left the phone. If Share is unavailable, a standard download link is used. Allow a couple of seconds before the blob URL is revoked.
Mail and Messages may recompress what you attach. If the point was a small WebP for a website, Save to Files and upload from a computer. If the point was “send this to a person,” JPG is often the less surprising attachment — set output to JPG on the converter instead of fighting the recipient’s client.
Memory
Safari will kill the tab if you decode four 48 MP images at full resolution. Convert fewer files, or set max width to 1280. The 25 MB warning and 80 MB hard stop exist so the page fails with a sentence instead of a white screen. This is not a daily quota.
Older iPhones with 3 GB of RAM are the reason encoding is sequential. Do not background Safari mid-convert and expect a worker to finish. If iOS dumped the tab, reopen Shift and convert again — there is no cloud job.
Orientation, screenshots, and AVIF on iOS
EXIF orientation is applied when the browser supports it, so a portrait shot should not land on its side. Screenshots are PNG; they can go to WebP, but thin type will soften. Keep PNG for UI captures you still need to read. AVIF encode on iOS is the flaky path Shift was built to tell the truth about. Displaying AVIF in Safari is not the same as writing one. Trust the badge.
Desktop walkthrough: guide. Codec choice: WebP vs AVIF. The usual laptop job: JPG to WebP.