Most "free online tools" follow the same pattern: upload your file to a server, process it with a backend script, and send the result back. It works, but it creates a privacy problem. Every file you process passes through someone else's infrastructure.
I wanted to prove there was a better way. Over 77 days, I built ToolKnit — a suite of 72 free online tools where zero files leave the user's device. No backend processing. No server uploads. Everything runs in the browser.
Here is how I did it, what I learned, and where I failed.
The Core Architecture
ToolKnit is a static site. No Node.js server, no Django app, no serverless functions. Just HTML, Tailwind CSS, and vanilla JavaScript sitting behind Nginx on a $5/month VPS. The only server-side code is a single PHP script (track.php) that records anonymous page-load counts — no file processing, no user data.
