When PNG is the right target for HEIC
Most people converting HEIC want JPG, and for sharing that is the right choice. PNG makes sense in a narrower set of situations. If you are going to retouch a photo in several sessions, each save as JPG adds a little more compression loss; working from a PNG master avoids that entirely. Some scientific, print-prepress and machine-learning workflows require lossless input and reject JPG. And if you need to archive a photo in the most universally readable format without further loss, PNG is a sensible companion to the original HEIC.
What changes in the conversion
HEIC is itself a lossy format: the iPhone compressed the photo with the HEVC codec when it was taken. Converting to PNG does not bring back that discarded detail, but it does guarantee that nothing more is lost from this point onwards. The image is decoded by libheif in a background Web Worker, the rotation flags are applied, and the pixels are written to PNG. Small images are additionally optimised with oxipng to keep the file size down without changing a single pixel.
Managing the file size
PNG files of photos are big. To keep them manageable:
- Reduce the dimensions with Resize Image if you do not need the full 12 or 48 megapixels.
- Consider HEIC to WebP at high quality, which is visually lossless at a fraction of the size.
- For everyday sharing, HEIC to JPG remains the most practical option.
Compatibility
PNG has been supported by every major operating system, browser and image editor for more than two decades, so a converted file will open on Windows, Linux, Android and older Macs that cannot read HEIC at all. That makes PNG a good handover format when you send photos to a designer or printer who has not told you what they can open.