Choosing an image format is a trade between three things: how small the file gets, whether transparency survives, and how much detail is thrown away for good. JPEG discards data to shrink photographs and cannot get it back, so every re-save costs a little more. PNG keeps every pixel and every transparent edge, at the price of size. WebP does both jobs and is smaller than either, but older software still stumbles on it. Quality is the same trade made by degrees rather than in one step, which is why a slider can shrink a photograph and do nothing at all for flat artwork. Every tool here says what the change costs — in bytes, and in what it takes away — before you commit to it.
Tools in this category
PNG to JPG
Convert PNG images to JPG, one file or a whole batch. The work runs on our server with libvips and nothing is kept once the result reaches you.
PNG to WebP
Convert PNG images to WebP without losing transparency, one file or a whole batch. Nothing is kept once the result reaches you.
JPG to WebP
Convert JPG photographs to WebP to cut page weight, in batches if you like. No account, no sign-up, and nothing is kept once the result reaches you.
JPG to PNG
Convert JPG to PNG, one file or many at once. Useful before editing, because every later save is lossless — though it cannot restore what JPEG discarded.
WebP to PNG
Convert WebP images to PNG for software that will not open WebP. Keeps transparency, takes a whole batch at once and keeps no copy of your file.
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How these tools are built
Every tool in this category is a definition rather than its own application, rendered by a shared engine, and the conversion itself runs on our server with libvips — no account, no sign-up and no copy kept once the result is on its way back to you. Format behaviour is transcribed from the organisation that defines it — the MDN image format guides and the relevant W3C specifications — and each page names its source next to the formula. A tool whose reference values stop reproducing fails the build and does not ship, which is the whole reason the catalogue grows slowly.