HEIF and RAW: What's the difference
HEIF is suitable for finished photos, RAW saves data for later processing. Changing the extension does not turn one format into another.
The finished snapshot and data for processing
HEIF stores the image prepared by the camera. RAW is a family of formats focused on further processing. Apple ProRAW combines RAW data with iPhone processing and is saved as DNG. It gives more opportunities to change exposure, color and white balance.
What to choose to send
A compatible JPG is usually enough to share a finished photo. Keep the original RAW file for editing. HEIF and RAW file sizes depend on camera settings and image content; size alone does not determine quality.
What this site can do
The converter accepts the supported HEIC/HEIF and saves JPG, PNG, WebP or PDF. RAW and ProRAW/DNG are not decoded here. Converting HEIF to PNG will not create RAW or restore data that is no longer in the source.