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Konvert: A Professional, Private File Converter in Your Browser

Konvert: A Professional, Private File Converter in Your Browser

July 7, 2025

I’ve always been fascinated by how far web technology has come. With Konvert, I wanted to prove that you don’t need bloated desktop apps or shady online services to convert files professionally you can do it all in the browser, safely and privately.

Konvert is a web-based file converter that transforms images, videos, and audio files between hundreds of formats all without uploading anything to a server. Everything runs locally using WebAssembly.

🎯 Why I Built It

Most “free” converters online either limit your file size, harvest your data, or bombard you with ads. I wanted something that:

  • Processes files instantly
  • Respects your privacy
  • Works offline once loaded
  • Has a clean, modern interface

So I decided to build it myself.

✨ What Makes Konvert Different

  • 100% Local Processing: Your files never leave your device. No uploads, no tracking.
  • Works Offline: Once the app loads, you can convert files without internet access.
  • No Limits: Convert as many files as your browser’s memory allows.
  • Batch Conversion: Drag in multiple files and process them all at once.
  • Multi-language: Supports English, Arabic, and French.
  • Accessible Design: Fully WCAG 2.1 compliant.
  • Dark Mode: Because everything looks better in dark mode.

🧠 What I Learned

WebAssembly with FFmpeg

Integrating FFmpeg WebAssembly was a game-changer. It let me bring professional-grade file conversion directly into the browser, no native binaries required.

Next.js 14 and TypeScript

I used Next.js 14 with the App Router and Server Components. This setup made the app fast to load and easy to maintain.

UI & Accessibility

I spent time refining the user experience with Tailwind CSS and Radix UI, making sure Konvert is responsive, intuitive, and accessible to everyone.

Performance and Memory

Handling large video and audio conversions taught me a lot about memory management and optimizing WebAssembly performance.

🛠 Tech Stack

  • Next.js 14 (TypeScript)
  • FFmpeg WebAssembly
  • Tailwind CSS
  • Radix UI

🎨 Screenshot

Konvert Screenshot

🔗 Try It Out

🙌 Final Thoughts

Building Konvert reminded me why I love web development. It’s exciting to see browsers become capable of tasks that used to be reserved for native apps.

If you often work with different file formats and want a fast, private alternative to traditional converters, give Konvert a try. I’d love to hear your feedback or ideas for new features.

— Maruf