DEV Community: Aizaz Ali

I Built a Privacy-First PDF Tool That Never Uploads Your File

Aizaz Ali — Sat, 24 Jan 2026 17:06:21 +0000

I Built a Privacy-First PDF Tool That Never Uploads Your Files

Hey everyone! 👋

I've been working on a side project for a while now, and I finally feel ready to share it with the dev community. It's called AeroPDF a collection of free PDF tools that run 100% in your browser.

No uploads. No servers touching your files. Just pure client-side magic.

Why I Built This

We've all been there. You need to quickly merge two PDFs or compress a file before emailing it. You Google "merge pdf online" and end up on some sketchy site that:

Uploads your file to who-knows-where
Shows you 47 ads
Asks you to "sign up for premium" after processing ONE file
Probably keeps a copy of your data forever

I got tired of it. Especially when dealing with sensitive stuff like contracts, invoices, or personal documents. Why should I trust a random server with my files?
So I thought: What if everything just happened locally?

The Tech Stack

For the curious devs out there, here's what powers AeroPDF:

Next.js 14 (App Router) For the framework and SSR
pdf-lib The backbone for most PDF manipulations (merge, split, rotate, etc.)
PDF.js Mozilla's library for rendering PDF previews
Tailwind CSS Because life's too short for vanilla CSS
Deployed on Netlify Simple, fast, free tier is generous

The key insight was that pdf-lib can do almost everything you need for basic PDF operations, and it runs entirely in JavaScript. No backend required.

How It Actually Works
When you drop a file into AeroPDF, here's what happens:

// Simplified example of merging PDFs client-side
import { PDFDocument } from 'pdf-lib';
async function mergePDFs(pdfFiles) {
  const mergedPdf = await PDFDocument.create();

  for (const file of pdfFiles) {
    const arrayBuffer = await file.arrayBuffer();
    const pdf = await PDFDocument.load(arrayBuffer);
    const pages = await mergedPdf.copyPages(pdf, pdf.getPageIndices());
    pages.forEach(page => mergedPdf.addPage(page));
  }

  return await mergedPdf.save();
}

That's it. The file goes from your device → browser memory → back to your device as a download. The server never sees it.

Features I'm Most Proud Of

Merge PDF Combine multiple files, drag to reorder
Split/Extract Pages Visual page picker
Compress PDF Reduces file size (with quality options)
PDF to Word Basic text extraction
E-Sign Draw or type signatures directly on documents
Password Protection Encrypt PDFs before sharing

And honestly, most of these took way less code than I expected once I figured out the pdf-lib API.

The Privacy Angle

I'm not just saying "privacy-first" for marketing. There's literally no backend processing.

No file uploads
No analytics tracking your documents
No cookies beyond what's needed for the site to function
Works offline once loaded (it's a PWA)

You can literally disconnect from the internet after the page loads and it still works. Try that with iLovePDF.

Lessons Learned

Browser APIs are powerful FileReader, Blob, URL.createObjectURL() are your friends
pdf-lib is amazing Seriously, huge thanks to the maintainers
SEO for tool sites is hard Competing with established players takes time
Users actually care about privacy The feedback I've gotten shows people appreciate not uploading files

What's Next?

I'm working on:

A Chrome extension for quick access

Try It Out

If you work with PDFs (and who doesn't?), give it a spin: aeropdf.app

It's completely free. No accounts. No limits. No BS.

Would love to hear your feedback or suggestions. And if you're interested in the technical details of any specific feature, drop a comment happy to write a deeper dive!

P.S. If you're building something similar and need help with client-side PDF processing, feel free to reach out. I've learned a lot of tricks along the way.

I Built a Privacy-First PDF Tool That Never Uploads Your Files

Aizaz Ali — Sat, 24 Jan 2026 17:02:05 +0000

I Built a Privacy-First PDF Tool That Never Uploads Your Files

Hey everyone! 👋

I've been working on a side project for a while now, and I finally feel ready to share it with the dev community. It's called AeroPDF a collection of free PDF tools that run 100% in your browser.

No uploads. No servers touching your files. Just pure client-side magic.

Why I Built This

We've all been there. You need to quickly merge two PDFs or compress a file before emailing it. You Google "merge pdf online" and end up on some sketchy site that:

Uploads your file to who-knows-where
Shows you 47 ads
Asks you to "sign up for premium" after processing ONE file
Probably keeps a copy of your data forever

The Tech Stack

For the curious devs out there, here's what powers AeroPDF:

Next.js 14 (App Router) For the framework and SSR
pdf-lib The backbone for most PDF manipulations (merge, split, rotate, etc.)
PDF.js Mozilla's library for rendering PDF previews
Tailwind CSS Because life's too short for vanilla CSS
Deployed on Netlify Simple, fast, free tier is generous

The key insight was that pdf-lib can do almost everything you need for basic PDF operations, and it runs entirely in JavaScript. No backend required.

How It Actually Works
When you drop a file into AeroPDF, here's what happens:

// Simplified example of merging PDFs client-side
import { PDFDocument } from 'pdf-lib';
async function mergePDFs(pdfFiles) {
  const mergedPdf = await PDFDocument.create();

  for (const file of pdfFiles) {
    const arrayBuffer = await file.arrayBuffer();
    const pdf = await PDFDocument.load(arrayBuffer);
    const pages = await mergedPdf.copyPages(pdf, pdf.getPageIndices());
    pages.forEach(page => mergedPdf.addPage(page));
  }

  return await mergedPdf.save();
}

That's it. The file goes from your device → browser memory → back to your device as a download. The server never sees it.

Features I'm Most Proud Of

Merge PDF Combine multiple files, drag to reorder
Split/Extract Pages Visual page picker
Compress PDF Reduces file size (with quality options)
PDF to Word Basic text extraction
E-Sign Draw or type signatures directly on documents
Password Protection Encrypt PDFs before sharing

And honestly, most of these took way less code than I expected once I figured out the pdf-lib API.

The Privacy Angle

I'm not just saying "privacy-first" for marketing. There's literally no backend processing.

No file uploads
No analytics tracking your documents
No cookies beyond what's needed for the site to function
Works offline once loaded (it's a PWA)

You can literally disconnect from the internet after the page loads and it still works. Try that with iLovePDF.

Lessons Learned

Browser APIs are powerful FileReader, Blob, URL.createObjectURL() are your friends
pdf-lib is amazing Seriously, huge thanks to the maintainers
SEO for tool sites is hard Competing with established players takes time
Users actually care about privacy The feedback I've gotten shows people appreciate not uploading files

What's Next?

I'm working on:

A Chrome extension for quick access

Try It Out

If you work with PDFs (and who doesn't?), give it a spin: aeropdf.app

It's completely free. No accounts. No limits. No BS.

Would love to hear your feedback or suggestions. And if you're interested in the technical details of any specific feature, drop a comment happy to write a deeper dive!

P.S. If you're building something similar and need help with client-side PDF processing, feel free to reach out. I've learned a lot of tricks along the way.

Building Privacy-First PDF Tools That Run Entirely in the Browser

Aizaz Ali — Fri, 16 Jan 2026 19:56:00 +0000

When I first started using online PDF tools, I noticed a common pattern: every tool required uploading files to a server (Majority). It seemed harmless at first, but then I realized many of these files are sensitive. Contracts, invoices, tax forms, medical records… and yet we trust these files to anonymous servers.

That didn’t sit right with me.

So I started experimenting with client-side PDF processing: running all the logic entirely in the browser. That means:

Files never leave your device
No server ever touches your documents
Everything happens locally, fast and securely

It’s not just a merger. On the site, you can now:

Merge PDFs
Split PDFs
Compress PDFs
Rearrange PDF pages
Delete PDF pages
Edit PDF metadata
Full PDF editor and More...

Each tool runs directly in the browser, so your data stays private.

Building this taught me a lot about browser APIs, memory constraints, and performance optimization. It also made me think more about privacy-first design: how can web tools be convenient, but still keep sensitive data safe?

I wrote a detailed guide explaining the how and why behind these tools, including step-by-step instructions and technical insights:
👉 Check it out here -> https://aeropdf.app/blog/merge-pdf-securely-guide

I Would love to hear from other developers: Have you built privacy-first tools?
What challenges did you face keeping everything client-side?