HEIC is usually better suited to photographs
HEIC is designed to store photographic images efficiently. It is commonly used by iPhones because it can keep photo files relatively compact while retaining strong visual quality.
For a large photo library, that storage efficiency can make HEIC more practical than saving every photograph as PNG.
PNG uses lossless compression
PNG stores raster images using lossless compression. Saving an image as PNG does not introduce the kind of lossy compression associated with formats such as JPEG.
That does not mean converting an HEIC photo to PNG restores information that was previously discarded. The PNG can only preserve the decoded image data it receives from the HEIC source.
PNG is useful for transparency and editing
PNG supports transparency and is widely used for screenshots, graphics, interface assets and images that may be edited repeatedly without introducing additional lossy compression.
If transparency exists in the decoded HEIC image, PNG can represent that alpha information in the converted output.
Why can PNG files be much larger?
Lossless compression generally makes PNG less space-efficient than formats designed specifically for compact photographic storage. A photograph converted from HEIC to PNG can therefore become significantly larger.
The exact difference depends on the image, so there is no fixed size ratio between HEIC and PNG.
Which format should you choose?
Keep HEIC when you are storing photographs and your devices and applications already support it. Choose PNG when you specifically need lossless output, transparency, or compatibility with a workflow that expects PNG.
- HEIC is usually the better storage format for supported photo libraries
- PNG is useful for lossless editing and graphics workflows
- PNG supports transparency
- Converting HEIC to PNG can substantially increase file size
- Keep the original HEIC if the source photo matters to you