Convert JPG to PNG
This is the one conversion on the site that usually leaves you worse off. A JPG turned into a PNG is typically three to five times larger and looks precisely the same, because PNG stores whatever it is handed perfectly — and what it is being handed here is an already-compressed JPEG. There are good reasons to do it anyway. They are just rarely the reason people arrive with.
Nothing is uploaded. Every image stays in this browser tab —here is how that works.
Whoever asked for a PNG may have meant something else
“Send it as a PNG” is usually shorthand, and it is worth working out for what. From a designer it normally means with transparency — a logo with nothing behind it, ready to sit on any background. From a print shop it means do not compress it any further. From a developer it sometimes just means not a JPG, because their pipeline handles PNG and SVG and nothing else has ever been tested.
Only the middle one is something this conversion actually delivers. If the request was really about transparency, the next section is the one that matters.
Converting cannot create transparency
A JPG has no transparency and never had any. The format has no alpha channel at all, so every pixel in the file is opaque, including the white ones behind your logo. Converting to PNG does give the image an alpha channel — but it arrives empty, every pixel fully opaque, because nothing in the source records which parts were ever meant to be see-through.
Getting a genuine cut-out is an editing job rather than a conversion: a selection tool or a background remover in an image editor, or a polite email to whoever made the logo asking for the original. A JPG of a logo on a white square is a dead end in this respect. Convert it if you like, and you will get a larger file with the white square still firmly attached.
How much bigger, and why
Three to five times is normal for a photograph, and ten times is not rare for a large one. PNG compresses by predicting each pixel from its neighbours and storing the difference, which works beautifully on flat colour and hard edges and very poorly on photographic detail. A JPEG’s fine blocky noise is, from PNG’s point of view, close to random data — and random data does not compress at all.
The same arithmetic explains the exception. A JPG that started life as a screenshot, a chart or line art compresses back down well, because the flat areas are still broadly flat underneath the artefacts. If your JPG is a picture of a spreadsheet, the PNG may come out about the same size, and occasionally smaller.
When it is genuinely the right move
Two cases, and both are about the destination rather than the picture.
The first is a hard requirement. A favicon generator, a Slack emoji uploader, an app-store asset spec, a laser cutter’s import dialog, a CMS with an oddly specific whitelist — these refuse a JPG outright, and a PNG is simply the shape the form wants. Nothing about the image improves; the form stops complaining, and that is the entire benefit on offer.
The second is compositing. If you are about to knock out a background, feather an edge or drop a shadow behind the image in an editor, the alpha channel has to exist before anything can be painted into it. Converting is a reasonable opening move in that job, as long as you understand it is only the opening move.
What changes when you convert JPG to PNG
PNG is lossless from here on — Benefit
Whatever the image looks like going in is exactly what comes out, pixel for pixel, and it will stay that way through any number of further PNG saves. That makes it the right target for a master copy, a screenshot, or anything with text and hard edges — and the wrong one for a photograph you want to be small.
The detail your JPEG already lost stays lost — Note
A JPEG has been through a lossy encoder at least once already, and the detail that pass discarded is gone from the file — nothing downstream can reconstruct it. Whatever you convert to inherits that starting point, so the honest goal here is to avoid adding a second helping of loss on top, not to recover the first.
A lossless target does not undo earlier loss — Note
Converting a lossy image to a lossless format preserves exactly what is in the file now, including every compression artefact it already carries. It does not repair them, and it usually makes the file considerably larger, because lossless compression has to store the artefacts faithfully too. Do this when you need the format, not when you want the quality back.
The quality slider does nothing here — size comes from dimensions — Note
A lossless target has no quality dial to turn, so the slider is disabled and the only lever that moves the file size is how many pixels there are. Halving the width and height quarters the pixel count, which is almost always a bigger saving than any encoder setting would have been. Set a max width you actually need rather than shipping the original dimensions.
Camera and location metadata are not carried over — Note
EXIF is dropped: the camera model, the exposure settings, the timestamp, and — the one that matters — the GPS coordinates of where the photo was taken. That is a privacy improvement for anything you are about to publish and a loss if you were relying on it for cataloguing. Orientation is the exception: it is applied to the pixels, so the image stays the right way up.
Output is sRGB — Note
Everything this tool writes is in sRGB, the colour space the web assumes. That is what makes the result look the same in a browser, a chat app and a photo viewer without an embedded profile to carry around.
Questions people ask about this conversion
Will converting to PNG make a blurry JPG sharper?
No. The blur, the blocking and the mushy text are in the pixels themselves, and PNG records pixels faithfully — including those. Sharper needs a better source: the original off the camera, a larger export from whoever made it, or a dedicated upscaler, which is a different job from a format conversion.
Is PNG better than JPG?
For screenshots, logos, diagrams and anything with text or transparency, comfortably. For photographs, no — several times the size for a picture nobody could tell apart. They were designed for different jobs, and most arguments about which is better are really arguments about which picture you have.
Can PNG handle a photo from my camera?
Technically, at any size, and the file will be enormous. A camera photograph is the case PNG was never meant for: millions of slightly different values with nothing repeating. If you want a lossless archive of a photo, keep the camera’s raw file rather than making a PNG from a JPG.
What about PNG-8 versus PNG-24?
PNG-8 holds a palette of 256 colours, like a GIF; PNG-24 is full colour. This tool writes full colour, because palettising a photograph produces visible banding for a saving that is rarely worth it. If you specifically need an 8-bit PNG for an old system, an editor with an export-for-web dialog is the right tool.
Related
Other things you can turn a JPG into
Try it with your own file
Drop an image in and see the result before you download anything.