DEV Community

Cover image for I built a free online PDF and image toolkit (no signup, no tracking)
DevBlocks42
DevBlocks42

Posted on

I built a free online PDF and image toolkit (no signup, no tracking)

A few weeks ago, I built a small web tool because I needed something simple: a way to manipulate PDF and image files without installing heavy software or creating accounts.

Most existing tools felt either:

  • overly complicated
  • behind paywalls
  • or full of ads and tracking

So I decided to build my own lightweight alternative.


What I built

It's a free online toolkit that runs entirely in the browser/backend, allowing users to process common file tasks:

  • Convert images to PDF or other image formats
  • Merge multiple PDF files into one
  • Add password protection to PDF files (using encryption)

Everything is designed to be fast, minimal, and accessible from any device.


Why this project exists

The main goal was simplicity.

I wanted:

  • no account creation
  • no email collection
  • no hidden paywalls
  • a tool that just works
  • GDPR compliant tool

It’s mainly built for quick everyday tasks like:

  • sending documents
  • organizing PDFs
  • converting images for administrative use

Tech stack

The project is built with:

  • FastAPI (backend)
  • Nginx (reverse proxy)
  • Cloudflare (DNS + security layer)
  • Vanilla HTML/CSS/JS frontend

The focus was more on performance and simplicity than on heavy frontend frameworks.


What I learned

Building a “simple tool” is surprisingly complex when you consider:

  • file handling safely
  • performance for large files (asynchronous jobs and event queue)
  • keeping the UI minimal but usable
  • making everything work across devices

Live demo

You can try it here:

https://universal-converter.fr.eu.org?language=en

Or in french language here:

https://universal-converter.fr.eu.org/?language=fr


Future improvements

I plan to add:

  • more image formats support
  • PDF compression
  • OCR features
  • OMR features using Audiveris
  • mobile UX

Feedback welcome

If you have suggestions or ideas for useful features, feel free to share them.
I’m mainly improving this project based on real usage.


Top comments (0)