PNG is the archival choice for iPhone photos
PNG (Portable Network Graphics) is a lossless format: it compresses by finding patterns, never by discarding detail. Converting HEIC to PNG gives you a file that survives unlimited re-saves and edits without generation loss, which is exactly what you want before heavy retouching or long-term archiving. The PNG specification has been stable since 1996 and is readable by effectively every device and program ever made since.
The trade-off is size. HEVC compression inside HEIC is one of the most efficient photo codecs in consumer use, and PNG gives all of that efficiency back. Our measurements with iPhone camera photos show a 2 MB HEIC turning into a 15 to 25 MB PNG. For screenshots and graphics the gap is smaller, because flat colors compress well losslessly.
Screenshots, cutouts and transparency
Two kinds of HEIC files genuinely need PNG. First, iPhone subject cutouts: when you lift a subject from a photo and save it, the result has a transparent background that JPG cannot represent. Second, screenshots and app graphics, where JPG's compression leaves visible halos around text and sharp edges. In both cases PNG reproduces the source exactly. For ordinary camera photos headed to the web, HEIC to JPG or HEIC to WebP gives you files a tenth of the size.
Common questions
Is HEIC to PNG really lossless?+−
The PNG step is lossless: every pixel that comes out of the HEIC decoder is stored exactly. Note that the original HEIC was already lossy-compressed by the camera, so PNG preserves the photo as it currently exists rather than adding any further loss.
Why are the PNG files so much bigger than my HEIC photos?+−
Expect a large size increase, often 5 to 10 times. HEIC uses aggressive HEVC compression; PNG compresses without discarding anything. A 2 MB HEIC photo commonly becomes a 15 to 25 MB PNG. That is the price of lossless storage. If size matters more than perfection, JPG at 90% quality is the better trade.
Does PNG keep transparency from my HEIC files?+−
Yes. If the HEIC contains an alpha channel, for example a subject cutout saved from the iPhone Photos app, the transparency survives in the PNG. This is the main reason to choose PNG over JPG, which flattens transparency onto white.
When should I pick PNG instead of JPG?+−
Pick PNG when you plan to edit the image further, need transparency, or are archiving graphics, screenshots and text-heavy images where JPG artifacts show. For photos going to a website, email or chat, JPG is smaller and visually identical.