JPG to PNG

// Why convert a lossy JPG into a lossless PNG

Every time a JPG is edited and re-saved as JPG, it is compressed again, and the artifacts compound. This generation loss is why a photo that has been through a few rounds of cropping and re-saving looks mushy. Converting to PNG first stops that cycle: PNG is lossless, so you can edit and re-save as many times as you like without the image degrading further.

The other common reason is simpler: the destination demands PNG. Design tools, documentation systems, and some upload forms accept only PNG, and a JPG needs to change costume to get in the door. Either way, the conversion is about what happens to the image next, not about the image as it is.

// The honest mechanics of the conversion

Your browser decodes the JPG, draws the pixels to a canvas, and writes them out as PNG. The output is a pixel-exact copy of the decoded JPG, so the artifacts already baked into the photo are preserved faithfully; PNG cannot reconstruct detail that JPG compression discarded years or seconds ago. The file will also grow, often substantially, because lossless encoding of photographic content is expensive.

The re-encode strips EXIF metadata, so camera settings and GPS data do not follow the image into the PNG. And no network is involved anywhere: the conversion runs locally and keeps working if you go offline after the page loads.

// fair questions

Are my JPGs sent to your servers?

No, there are no servers involved at all. Your browser performs the whole conversion on your device, and the photo never leaves it. You can even disconnect from the internet after loading the page.

Does converting to PNG make the photo higher quality?

No. The PNG is an exact copy of the JPG as it currently looks, artifacts included. What it buys you is that no additional quality is lost from this point forward, however many times you edit and re-save.

Why is the PNG file so much larger than the JPG?

JPG discards detail to hit small file sizes; PNG keeps every pixel value exactly. For photographic content that honesty is expensive, so a size increase of several times is normal.

Will the PNG have a transparent background?

No. JPG has no transparency to begin with, so the resulting PNG is fully opaque edge to edge. This is a format converter, not a background remover.