Convert JPG to PNG

No, and this is the most common misunderstanding. A JPG has already thrown detail away, and converting to PNG cannot bring it back. The PNG will look exactly like the JPG, just in a lossless container and a much bigger file. PNG protects quality from that point on; it does not restore what was already lost.

Because PNG is lossless: it records every pixel exactly, with none of the compression that makes JPG small. In our test a 213 KB JPG became a 2.03 MB PNG, about ten times larger, for an identical looking image. That is normal and expected for a photograph.

When you need a lossless working copy to edit repeatedly without quality loss piling up, when a tool or upload only accepts PNG, or when you are about to add transparency. For simply storing or sharing a photo, keep the JPG.

Converting to PNG gives you a format that supports transparency, but it does not create any: your photo still has its original solid background. To actually cut the background out, use the Background Remover, which outputs a transparent PNG directly.

No. Every pixel of the JPG is copied exactly into the PNG. The only thing that changes is the file format and the size.

Yes. Drop a whole folder and each is converted with the same settings, then download them individually or as a single ZIP.

No. Conversion runs in your browser through the Canvas API, so your JPG never leaves your device.