Convert PNG to JPG

What the png to jpg converter shows you before it runs

Drop the files, paste a screenshot, or pick them from disk. Each one comes back with a thumbnail, its pixel dimensions, what it weighs now, and an estimate of what it will weigh after conversion at the quality you have selected. Two more facts appear on the files that have them: whether the image carries transparency, and whether it looks like the kind of picture JPEG is good at.

That second flag is the one most converters leave out, and it is the one that decides whether this conversion is worth doing at all. The order matters more than it sounds. If the estimate only arrives after the work is done, you have already committed to a result you could not evaluate.

A photograph shrinks enormously. A screenshot may not shrink at all

A photograph stored as PNG is close to the worst use of that format. PNG stores every pixel exactly, and photographic detail is millions of slightly different values with no repetition for the compressor to exploit. JPEG was designed for exactly that material: it discards the fine variation your eye is least likely to notice and keeps the structure. Converting a PNG photograph often removes eighty to ninety-five percent of the file, and at normal viewing size you would struggle to tell the two apart.

Now take the other common PNG: a screenshot, a chart, a logo, a diagram, a slide export. Large areas of one flat color with hard edges cutting through them. That is the case PNG compresses brilliantly, and it is the case JPEG handles worst. JPEG works in eight-by-eight blocks of pixels, and a sharp black line against white is a discontinuity it cannot describe cheaply. It spends bytes trying, and it leaves faint ringing — a gray shimmer around every letter and every border. The result can come out both larger than the PNG and visibly dirtier, which is the least useful outcome a converter can produce.

This tool checks the pixels rather than guessing from the file name. When the estimate goes up instead of down, it says so on the card before you convert, and it says so again on the receipt with a plus sign rather than reporting a saving that did not happen. If your file is in that category, the right move is usually to keep the PNG.

Transparency has to become a color, and white is the default

JPEG has no alpha channel. There is nowhere in the format to record that a pixel is partly or fully see-through, so every transparent pixel has to be given a solid color on the way out. There is no setting that changes that and no encoder that works around it.

What differs between tools is which color they pick silently. A blank canvas in a browser starts out as transparent black, so a converter that flattens without asking commonly hands back a logo sitting in a black rectangle. White is the default here because white is what most people mean when they say background — the page, the document, the slide. The color picker appears only when at least one of your files actually contains transparent pixels, and the affected files are named before the run rather than discovered afterward.

If keeping the transparency is the point, this is the wrong conversion. Keep the PNG, or if you need the image inside a document, place the images into a page directly withimages to PDF, which preserves the alpha rather than flattening it.

The loss is real, and choosing the quality is choosing how much

JPEG is lossy on purpose. The quality slider is not a polish control — it is the dial that decides how much detail gets thrown away, and that is the same dial that decides the file size. At the default, photographic material is indistinguishable from the source at one-to-one on screen. Below about sixty you start to see it first in skies, skin tones and smooth gradients, where blocking has nothing to hide behind.

Because the images stay decoded in the tab after a run, changing the quality and converting again costs one click and no re-upload. That is deliberate: picking a quality number in the abstract is guesswork, and comparing two actual results is not.

You do not get the original back afterward

The discarded detail is gone permanently. Converting the JPG back to PNG later produces a lossless copy of a lossy image — bigger than the JPG, no better looking, and still carrying every artifact the JPEG encoder introduced. Each further round trip through JPEG degrades it again, which is why editing a JPG in place across several sessions visibly ruins it.

So keep the PNG if there is any chance the image gets edited again. Convert for the thing you are about to do — the email, the upload, the listing, the web page — and treat the JPG as the delivery copy rather than the master. If you want the reasoning behind which format belongs where in the first place, JPG vs PNG covers it properly.

When a different tool is the better answer

If you are aiming at a specific number rather than a specific format — under 2 MB for a portal, under 5 MB for an email attachment — converting and then eyeballing the slider is the slow way around. Compressing to a target size searches for the quality that lands under your limit instead of making you guess and re-run, andhow to reduce file size walks through the cases where the format is not the problem at all.

And if you arrived here from the wrong side — you have a JPG and something you are uploading to demands a PNG — the conversion runs the other way atJPG to PNG. That page is worth reading before you use it, because that direction makes the file larger without making the picture better, and it says so.

Everything on this page happens in this tab. Your browser already decodes PNG and already writes JPEG, so there is no server in the path, no upload endpoint, and no size cap beyond your own device memory. One consequence: a canvas writes pixels and nothing else, so any metadata in the source PNG does not survive the trip.