Every "free online tool" site I've ever used follows the same playbook: upload your file to their server, wait, download the result — usually after a signup wall, a file-size cap, or a watermark slapped on your output. Your data sits on someone else's machine, and you just have to trust that they delete it. I didn't love that. So I built ToolKnit — 58 free online tools that run entirely in your browser . No backend server. No file uploads. No accounts. No database. Just static HTML, CSS, JavaScript, and a pile of WebAssembly. Here's how it all works under the hood. The Architecture: There Is No Server ToolKnit is a static site. Every page is plain HTML served from a single origin. There is no Express server, no Lambda function, no S3 bucket receiving your files. When you compress a PDF on ToolKnit, the compression happens on your device . When you convert a PNG to WebP, your browser's Canvas API does the pixel work. Nothing leaves your machine. This isn't a philosophical choice — it's a technical one.…