Lossless means PNG, not magic
HEIC already stores a lot of camera detail in a small file. The disaster is a converter that JPEG-encodes first “because it is easier,” then writes PNG from that mush. You cannot recover what the JPEG discarded. This path decodes the Apple container and writes PNG, a lossless format: no new blockiness, native dimensions, files that are larger on disk because they should be. Start from the Photos master, not a Messenger download. Local encode means no farm silently downscaling for bandwidth. Photographers use this before print proofs and retouch. After you have a PNG master, you may still export JPEG or WebP for the live site — but start lossless. PNG will not invent megapixels. A 640 px crop stays 640 px of information even if you later enlarge. For true press plates, some teams still prefer TIFF. PNG is the web-and-editor-friendly lossless cousin.