JPG to PNG converter
Convert JPG files to PNG inside this page. No upload, no limit on how many, no watermark.
- 0 uploads
- No limits
- No signup
- Works offline
JPG and PNG, side by side
| JPEG | PNG | |
|---|---|---|
| Released | 1992 | 1996 |
| Compression | lossy | lossless |
| Transparency | no | yes |
| Animation | no | no |
| Support | everywhere, without exception | everywhere, without exception |
What actually changes
Worth understanding what this does and does not achieve. The output is lossless from now on, so further edits will not degrade it — but the JPEG artefacts already baked into the source are preserved perfectly, and the file will get several times larger. This is a useful step before editing, not a quality upgrade.
JPEG is the format the web was built on, using discrete cosine transform compression tuned for photographs, released in 1992. Its real strength is that universal compatibility — every device, browser, printer and form on earth reads it. The reason you are on this page is almost certainly the other side of that coin: no transparency, visible ringing around sharp edges and text, and a compression scheme three decades behind the state of the art.
PNG arrived in 1996 and is a lossless format built around DEFLATE compression and a full alpha channel. It gives you pixel-exact reproduction and true transparency, which makes it right for screenshots, logos and line art. The trade-off worth knowing about before you commit: file sizes several times larger than a lossy format when the content is photographic.
How the conversion works here
Your file is decoded in a Web Worker inside this browser tab — by the browser's own image pipeline where it can, and by a WebAssembly build of libheif or libavif where it cannot. The decoded pixels are then re-encoded with OxiPNG, the same encoder Squoosh uses.
All of that happens on the processor in front of you. There is no upload step, no queue and no server, which is why there is no size cap, no daily allowance and no paid tier — and why the whole thing keeps working with the network switched off.
Doing more than one thing
Most people converting a format also need it smaller or a different size. The result screen hands your converted files straight to the compressor or the resizer in one click — no second download, no re-selecting files. If you need several formats, the general converter lets you pick the output each time.
How it works
- 01Add your JPG filesDrop them on the page, click to browse, paste from the clipboard, or drop a whole folder.
- 02Conversion runs on your deviceEach file is decoded and re-encoded as PNG by a WebAssembly codec in a background thread. Nothing is uploaded.
- 03Adjust if you need toPNG has no quality setting; enable the lossless optimiser to shrink the result further.
- 04DownloadSave one file, or take the whole batch as a zip built on your device.