What converting JPG to PNG actually does
This tool decodes your JPG into its raw pixels, then saves those exact pixels as a PNG. PNG is a lossless format, so the copy is pixel-perfect: what you see in the JPG is precisely what you get in the PNG, now and after any number of re-saves. Everything happens in your browser using the canvas element. The image is never uploaded, never stored and never seen by anyone else.
The most common reasons to do this are practical rather than aesthetic: an upload form that only accepts PNG, a design tool that prefers it, or the start of an editing session where you want to stop any further quality loss before it begins.
Why it cannot restore lost quality
This is the honest part, and it matters. JPG is a lossy format: when the photo was first saved as a JPG, fine detail was thrown away to make the file small. That detail no longer exists anywhere in the file, so no converter, this one included, can bring it back. Converting to PNG gives you a perfect copy of the JPG as it looks today, compression artefacts and all, stored in a format that will never degrade it further.
Think of it like photocopying a photocopy. The PNG is a flawless copy of the current state, but it cannot recover what the first copy lost. If you have access to the original photo, a RAW file or an uncompressed export, always convert from that instead.
When PNG is worth it
PNG earns its larger file size in three situations. First, repeated editing: every time a JPG is edited and re-saved as a JPG it loses a little more quality, while a PNG can be opened and saved endlessly with zero loss. Converting once at the start of an editing job stops the rot. Second, hard requirements: some forms, printers and content systems simply demand PNG. Third, future transparency: if you plan to cut out the background in an editor, you will need a format that can store the result, and PNG can.
What PNG is not worth is storage or sharing of ordinary photos. A PNG photo is a much bigger file that looks identical, so for sending and archiving, the JPG you already have is fine.
About the file sizes
Expect the PNG to be several times larger than the JPG. That is normal. Both formats start from the same raw grid of pixels:
The size rows above the download button show the real numbers for your image, so you can decide whether the trade is worth it before saving.
Frequently asked questions
Will converting to PNG improve the quality of my JPG?
No. Detail that JPG compression discarded is gone for good, and no format change can bring it back. The PNG is an exact, lossless copy of the JPG as it is now, artefacts included. What PNG does guarantee is that no further quality is lost from this point on.
Why is the PNG bigger than my JPG?
Because PNG stores every pixel losslessly while JPG threw detail away to stay small. Storing the same picture exactly simply takes more bytes, and for photos the PNG is often five to ten times larger. That is expected and not a sign anything went wrong.
When is converting JPG to PNG worth it?
When an upload form or piece of software insists on PNG, and when you are about to edit an image repeatedly. Editing a PNG and re-saving costs nothing, whereas every re-save of a JPG loses a little more quality. Converting once to PNG before a long editing session stops that decay.
Does the PNG get a transparent background?
No. JPG has no transparency, so there is none to carry over. The PNG will look identical to the JPG. If you need the background removed, that is an editing job rather than a conversion job.
Is my image uploaded anywhere?
No. The conversion happens entirely in your browser using the canvas element. Your image never leaves your device and nothing is stored.