I kept running into the same problem. Every time I needed to convert a file, the tool wanted me to upload it to some server first. Tax documents, client spreadsheets, medical images. All leaving my machine before anything happens. The "secure" ones weren't much better. I checked a few with DevTools and found Google Analytics, Microsoft Clarity, and session replay scripts running on tools that promise "100% private." So I decided to build one where the privacy claim is actually verifiable. Open any converter on ConvertSafe, open your browser's Network tab, and convert a file. You'll see zero requests carrying file data. Everything runs in browser memory using the Canvas API, WebAssembly, and JavaScript libraries that load on demand. The trickiest part was making it fast without shipping a massive bundle. Libraries like heic2any (iPhone photos), pdfjs (PDF rendering), and SheetJS (spreadsheets) are heavy. So each one lazy loads only when someone actually needs that specific conversion. First use has a brief pause, every use after that is instant. I wrote a full technical breakdown on Dev.to if you're curious about the architecture: https://dev.to/abdul_jabbar/i-bu... Would love to hear what formats or features you'd find useful. Happy to answer any questions about how it works under the hood.

ConvertSafe

Convert files 100% privately in browser. Nothing uploaded

Convert files 100% privately in browser. Nothing uploaded