In-browser image optimizer
Convert JPEG to PNG
This conversion cannot add quality back — the JPEG already threw those pixels away. What it buys you is a lossless container: further edits will not degrade the image, and every editor and upload form accepts it.
Convert JPEG to PNG in three steps
- Open the JPEGThe browser decodes it instantly; no upload is involved at any point.
- Choose PNG on the right paneOxiPNG writes a lossless PNG of exactly the pixels the browser decoded — nothing is re-compressed on top.
- Compare the sizes before you commitA photograph will be two to five times larger as PNG. For screenshots and graphics the difference is much smaller, which is where this conversion usually makes sense.
What you gain, and what you do not
You gain a lossless file: re-saving it repeatedly will not add artefacts, and transparency can be added later with clean edges. You do not gain detail, sharpness or "original quality" — those bytes are gone, and any tool claiming otherwise is describing how PNG works, not what it can recover.
When JPEG to PNG is the right call
You are about to edit the image and want to avoid a second lossy generation, you need an alpha channel, or you are feeding a tool that rejects JPEG. If the file just needs to be smaller, go the other direction: compress the JPEG or convert it to WebP.
What to expect
| Source | PNG output | Worth it? |
|---|---|---|
| JPEG photo, for the web | 2–5× larger | no — convert to WebP instead |
| JPEG screenshot or graphic | 1–2× larger | sometimes |
| JPEG you are about to edit | larger | yes, to stop further loss |
| JPEG that needs transparency | larger | yes |
Questions
Does converting to PNG improve quality?
No. PNG stores what the JPEG already contains. It prevents further loss from future saves, which is a different thing.
Why is the PNG so much bigger?
PNG is lossless and general purpose; JPEG is lossy and tuned for photographs. The same picture needs far more bytes when you refuse to discard anything.
Is anything uploaded?
No. The decoder and encoder run in your browser, and the network panel shows no upload while the conversion happens.