Convert PNG images to JPG in your browser. The file never leaves your device — there is no upload, no queue and no copy left on a server.
Convert PNG images to WebP without losing transparency. Everything runs in your browser, so nothing is uploaded and nothing is stored.
Convert JPG photographs to WebP to cut page weight. The conversion happens in your browser, with no upload and no account.
Convert JPG to PNG in your browser. Useful before editing, because every later save is lossless — though it cannot restore what JPEG already discarded.
Convert WebP images to PNG for software that will not open WebP. Runs in your browser, keeps transparency, uploads nothing.
Tell us what is missing and where its numbers should come from.
What should it convert, calculate or generate, and where would the authoritative numbers come from? A link to the standard or publication that defines them is the most useful thing you can send.
Opens your mail app with this page already filled in.
Every tool in this category runs entirely in your browser: there is no upload, no account and no request to a server once the page has loaded. The numbers behind them are transcribed from the organisation that defines them — NIST for units, the W3C for web formats, the WHO for health measures — 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.