How I built 15 browser tools with zero backend

Every "free online tool" I reached for wanted an upload, an account, or both. So I built 15 that need neither — and the constraint that made that possible turned out to be the best decision in the project: no backend at all.

Here's what runs where.

The browser can do more than we give it credit for

• Image work (HEIC→JPG, compress, resize, strip EXIF): <canvas> + createImageBitmap, and WASM (heic2any) for formats the browser can't decode natively.
• PDF split/merge: pdf-lib, entirely client-side.
• QR codes, password generation, JSON formatting, word counting: plain JS + crypto.getRandomValues and Intl.Segmenter.

Nothing touches a server. "Your files never leave your device" isn't a privacy promise you have to trust — it's just how the thing works. Open DevTools → Network and watch: no request fires when you convert a file.

Why no-backend is a superpower for a solo dev

• $0 to run. A zero-dependency static site generator emits plain HTML; Cloudflare Pages serves it free. 272 pages (15 tools × 16 languages + hub) cost nothing.
• Nothing to operate. No servers, no uploads to secure, no data to leak, no scaling. The whole "ops" surface is a git push.
• It's genuinely private, which is a real differentiator when every competitor uploads your file to "process" it.

The tradeoffs (being honest)

• No accounts, no cross-device sync, no server-side history. For utilities, that's fine — you do one thing and leave.
• Some formats (TIFF, exotic codecs) the browser just won't decode; you draw the line and say so.
• SEO is the whole growth engine, since there's no viral loop. That's the part I'm still figuring out.

If you're sitting on a "should this be a SaaS or just a tool" decision: a surprising amount can be just a tool, and shipping it that way is faster, cheaper, and more private.

Tools are here if useful: https://boring-tools-6ip.pages.dev — happy to go deeper on any part of the stack in the comments.