Image converter

The picture is decoded by the browser, drawn on a canvas at its full size, and encoded again in the format you choose. That means three formats out — PNG, JPEG and WebP — because those are the three every browser can write. It reads more than it writes: AVIF, BMP, GIF and SVG come in fine if this browser decodes them, and the page checks rather than assumes. AVIF and JPEG XL are not offered as outputs, and the honest reason is that no browser will encode them from a canvas: producing them needs a WebAssembly codec of a megabyte or more shipped with the page, which this site will not do for one button.

Going to JPEG throws away transparency, so any transparent area becomes the colour you pick — white unless you say otherwise — and the page says so before you download rather than after you notice. PNG is lossless: converting a JPEG to PNG cannot recover what JPEG already discarded, and the file usually grows several times over, which is why the size change is printed in both directions. Quality applies to JPEG and WebP only; PNG ignores it.

Two things do not survive the canvas: metadata and animation. EXIF, GPS and the colour profile are gone from the result — usually what you want, and worth knowing when it is not — and an animated GIF or WebP arrives as its first frame alone. The page says which of those applied to your file.

Everything happens in this tab. The file is read with FileReader, the page makes no network requests, and nothing you drop is stored; the Dark button keeps its own setting in this browser's local storage.