GunkyJunky Making your digital life easier

Why Client-Side Processing Matters for Your Privacy

• 2 min read • GunkyJunky Team
privacy technology

Understanding the difference between uploading your files to a server versus processing them in your browser—and why it matters.

When you use most online PDF tools, here’s what typically happens: you upload your file to their server, they process it, then you download the result. Sounds convenient, right? But there’s a better way.

The Upload Problem

Every time you upload a file to a server:

  1. Your file leaves your device and travels across the internet
  2. Someone else stores it (even if temporarily)
  3. You lose control over what happens to it
  4. You trust them to delete it (maybe they do, maybe they don’t)

For many files, this isn’t a big deal. But what about:

  • Tax documents
  • Medical records
  • Contracts with sensitive information
  • Personal photos or correspondence

Do you really want those on someone else’s server?

The Client-Side Alternative

Client-side processing means the work happens in your browser, on your device. Nothing gets uploaded. Nothing leaves your computer.

How It Works

Modern browsers are surprisingly powerful. They can:

  • Manipulate PDF files directly
  • Compress images
  • Merge and split documents
  • All without internet (after the page loads)

Our tools use this approach. When you compress, split, or merge a PDF:

  1. You select your file (it stays on your device)
  2. Your browser does the work (using JavaScript)
  3. You download the result (created locally)
  4. We never see your file

The Trade-offs

Client-side processing isn’t perfect:

  • Slower for huge files: Your device has less power than a server
  • Limited by your device: Old phones might struggle
  • No cloud storage: You manage your own files

But for most PDF tasks, these trade-offs are worth it for the privacy gain.

How to Know the Difference

Want to know if a tool is truly client-side? Here’s a test:

  1. Load the tool page
  2. Disconnect from the internet
  3. Try processing a file

If it still works, it’s client-side. If it fails, your files are being uploaded.

Our Philosophy

We believe your files are yours. Period. That’s why we built our tools to run entirely in your browser. It’s a bit more complex for us to develop, but it’s the right thing to do.

In a world where data breaches make headlines weekly, the best protection is not collecting data in the first place.

Your files. Your device. Your privacy.