DEV Community

Shahzaib
Shahzaib

Posted on

Stop Uploading Sensitive PDFs to Random Websites

#privacy #security #showdev #webdev

Stop Uploading Sensitive PDFs to Random Websites

Every time you upload a contract, medical record, or financial statement to a "free PDF tool" site, you're trusting a stranger's server with your most sensitive documents.

Here's what actually happens on most free PDF sites:

  1. Your file uploads to their server
  2. It sits there (for how long? who knows)
  3. It gets processed, maybe logged, maybe backed up
  4. You hope they delete it

There's a Better Way: Browser-Side Processing

Modern browsers can do everything a server can for PDF work:

  • pdf.js extracts text from any PDF
  • pdf-lib merges, splits, rotates, edits
  • Tesseract.js does OCR on scanned pages
  • Canvas API renders pages to images

None of this needs a server. Your file never leaves your device.

What I Built

PdfWord (https://pdfwordtools.pages.dev) runs 47 PDF tools entirely in your browser:

  • Merge, split, compress, convert, edit, sign
  • 11 AI tools (summarizer, MCQ generator, chat with PDF, contract checker)
  • Works offline as a PWA after first load

The only exception: AI tools send extracted text (not your file) to the AI. Everything else is 100% local.

How to Tell If a "Free" Tool Is Safe

Open DevTools → Network tab → upload a file → if you see your file in an upload request, it's going to their server. Check if it works offline (airplane mode) — if yes, it's truly client-side. Read the privacy policy — vague = red flag.

The Rule

If a free tool needs your file on their server to do something your browser can do alone, find another tool.

Try it: https://pdfwordtools.pages.dev — disconnect your internet after loading, everything still works.

47 free PDF tools. No signup. No server uploads. Building in public.

Top comments (0)