Convert a JPG to PNG
What this tool does
This page starts with PNG selected as the output, so a dropped JPEG comes back as a PNG. Expect the file to be bigger, and know that it will not look sharper.
Pre-set for you: PNG output. You can change it before you drop a file.
This browser cannot convert images locally. It needs Web Workers with OffscreenCanvas support, and we will not fall back to converting on the main thread because that would freeze the page. Please try a current version of Chrome, Edge, Firefox or Safari.
That is a HEIC or HEIF file, the format iPhones and many cameras shoot by default. This browser cannot decode it natively, so a decoder is fetched from this site to read it — still on your device, still never uploaded.
How this works
The image is decoded, redrawn and re-encoded inside a Web Worker in this browser tab. Nothing is uploaded, and there is no file-size limit imposed by a server because there is no server.
- The format list is built from what your browser can actually encode, tested at load time. A format the browser cannot write is not offered, rather than silently producing something else.
- Converting to JPEG flattens transparency onto white, because JPEG has no alpha channel. The result panel says so when it happens.
- HEIC and HEIF files from an iPhone work: Safari reads them directly, and other browsers fetch a small decoder that runs on your device.
- A batch converts every image to the same format and returns them as one ZIP.
- Re-encoding an already-optimised image can add a few bytes. The readout shows what actually happened rather than promising a saving.
Converting JPEG to PNG is a different kind of conversion from the other way round, and the honest summary is that it costs you file size without giving you better pixels. JPEG is lossy: the compression artefacts are baked into the file the moment it is saved. Decoding it into PNG stores those same pixels exactly and losslessly, but it cannot undo the compression that already happened.
So why do it? Because PNG has two properties JPEG does not.
- PNG can hold transparency. A JPEG decoded into a PNG gives you a canvas with an alpha channel, so you can cut the subject out afterwards and save it with the background removed. Starting from JPEG is a one-way door for transparency otherwise.
- PNG stores its pixels without further loss. If you are about to edit and re-save an image, editing a PNG means the only generation loss is the one already in the source, rather than a new one added by every save.
The cost is real and worth stating plainly: the PNG will usually be several times larger than the JPEG it came from. Lossless storage means exactly that — the detail is kept rather than approximated. For a 2 MB photograph, expect a PNG in the range of five to fifteen megabytes, and that is not a bug or a badly written converter, it is what lossless means.
With PNG selected here, the format list is driven by what this browser proves it can actually write, so PNG is always on it. Transparency cannot be added to a JPEG, because there was none to begin with — the conversion gives you the possibility of it, not the thing itself.
A batch converts in one pass with the files kept in drop order, then downloads as a single ZIP. That is the sane way to handle a folder of JPEGs you are about to edit, rather than repeating the conversion one file at a time.
Frequently asked questions
Will a PNG look better than the JPEG it came from?
No. JPEG compression is already in the source, and a lossless format cannot restore what was discarded. The PNG is a faithful copy of the pixels the JPEG decodes to, nothing more.
Why is the PNG so much bigger?
Because it stores every pixel losslessly instead of approximating detail to save space. A file several times the size of the JPEG is the expected result, not a sign of a problem.
Does the PNG have a transparent background?
No — a JPEG has no transparency to begin with. The PNG simply has an alpha channel ready, which is what you need if you plan to remove the background afterwards.
Can I convert a whole folder of JPEGs?
Yes: drop them as a batch, and they come back as PNGs in the same order, packaged in one ZIP.
Convert Image Format with different settings
Pick the format you want out, and the image is decoded and re-encoded in your browser tab. Transparency, colour and orientation are handled for you, and the file never reaches a server.