Going from JPG to PNG will not magically restore detail a JPG already discarded, but it stops any further loss and gives you a clean, lossless canvas for editing. That is exactly what you want before you start layering, masking, or adding transparency in an image editor — every subsequent save stays pixel-exact. PNG is also the safer format for graphics you will share repeatedly, since re-saving a JPG over and over slowly degrades it.
Building a clean editing canvas before you retouch
Designers reach for PNG the moment a JPG needs real work. Every brush stroke, crop, and colour adjustment you make on a JPG forces the editor to re-compress on save, and those repeated passes quietly smear fine detail. Converting to PNG once, up front, freezes the pixels: from that point on every save is bit-for-bit identical no matter how many times you revise. This is why icon sets, UI mockups, and product shots destined for repeated edits live as PNG until the very last export. It also unlocks a real alpha channel, so you can knock out a background and drop the subject onto any colour later. When you are finished and ready to publish a photo, send it back through PNG to JPG to recover small, fast-loading files.
When platforms and pipelines demand PNG specifically
Plenty of systems simply refuse JPG. Sticker and emoji uploads, browser extension icons, app-store screenshots, and many print-on-demand services accept only PNG because they need lossless edges or transparency. Converting first saves a frustrating rejection at the upload step. PNG is also the safer archival choice for anything text-heavy, like a scanned form or a chart, since JPG's lossy noise muddies sharp lines. Keep in mind the file grows — a lossless format stores far more — so reserve PNG for cases that truly need it rather than every photo. If your goal is just smaller graphics that stay sharp, the PNG compressor trims bulk without abandoning the format, and PNG to WebP shrinks further while keeping transparency.