Safari is the app
Add photos from the picker. Multi-select works. Encoding is local. Large batches are easier on a desktop because of memory and the ZIP step.
Why it matters
- App Store converters are noisy.
- HEIC is native on iOS; this site can encode WebP in Safari.
- You can AirDrop the result to a laptop.
How to do it
- Open the converter in Safari. Allow file access.
- Select a few photos (start small on older phones).
- Convert. Save the free download to Files. Use a computer for 50+ images.