A PNG stores every pixel exactly, which is right for a logo or a diagram and wasteful for a photograph. Measured on a 1280-pixel photograph: 468 KB as a PNG against 108 KB as a JPEG — the same picture at a quarter of the weight, because JPEG discards detail the eye does not miss and PNG is not allowed to discard anything.
One, or up to 20 together. Screenshots, exports and photographs saved the wrong way all qualify.
The conversion runs on our side. Anything transparent is filled in, because a JPEG has no way to store transparency.
Each file has its own button, and a batch arrives as a single zip.
Step by step, with screenshots: How to convert a PNG to JPG
Almost always. PNG is lossless, which means it is obliged to keep information a photograph does not need — sensor noise, imperceptible gradients in a sky — and it has no way to throw any of it away. That is exactly right for a screenshot of text or a logo with flat colour, and it is why a photographic PNG is routinely four or five times larger than it needs to be.
They become solid. JPEG cannot store transparency at all, so anything see-through has to be filled in before the file is written. If the transparency matters, WebP keeps it and is smaller than PNG anyway.
Usually not. Screenshots are mostly flat colour and sharp text, which is the case PNG compresses brilliantly and JPEG handles badly — text edges pick up a visible fuzz. A screenshot of a photograph is the exception.
Up to 20 files at a time, and they come back as one zip. For a bigger pile, the batch compressor handles the same job with the folder in mind.
Free Online Image Optimizer