Privacy
Your videos are never uploaded. The compressor is FFmpeg compiled to WebAssembly and it runs inside your browser tab. Your file is read from your disk by the page, processed in memory, and handed back to you as a download. There is no upload endpoint on this site at all.
You can check that rather than believe it. Open your browser's network panel while you compress: every request is to this domain for the page's own files, plus page-local blob: URLs. There is no POST. Or more simply: load the page, turn your Wi-Fi off, and compress anyway.
The site's Content-Security-Policy enforces it. connect-src 'self' blob: means the page is not permitted to send your data anywhere else, even if some future bug tried to.
What we collect
Nothing. No analytics, no cookies, no fingerprinting, no accounts, no email addresses, and no record of what you compressed. This site is static files.
What the engine downloads
The first time you compress, your browser downloads the 31 MB FFmpeg WebAssembly engine from this domain and caches it. It is served from here rather than a public CDN specifically so that no third party learns you were here.
The iPhone app
The app compresses on the device too. Its store privacy policy is here and its terms are here.