Why I Built a 100% Client-Side PDF & Image Suite That Works Offline

Saurabh Kumar Sharma — Wed, 22 Jul 2026 20:35:57 +0000

Most of us use online tools like TinyPNG or iLovePDF to quickly compress a screenshot or merge a document. But have you ever thought about where those files go?

For businesses handling sensitive tax forms, signed contracts, or personal photos, uploading assets to third-party databases is a massive security compliance risk.

That's why I built Resizer Tools—a completely browser-native suite of 26 utility tools.

How it works under the hood

Instead of sending files to a server-side API, Resizer Tools delegates 100% of the computation to your device's local engine:

PDF Compilation: We use client-side streaming via pdf-lib to stitch pages and encrypt layouts.
Image Downscaling: We leverage the browser's native Canvas API and WebGL vectors to compress assets up to 80% with zero quality loss.
Offline Mode: Since all JavaScript libraries run locally in your browser memory, you can open the site, disconnect your Wi-Fi, and keep processing files without issue.

Check it out here: https://resizertools.com

I would love to get your thoughts on the architecture, speed, and what tools we should build next!

DEV Community: Saurabh Kumar Sharma

Why I Built a 100% Client-Side PDF & Image Suite That Works Offline

How it works under the hood