How I Built a Fast, Client-Side JSON Viewer for Developers

Source: Dev.to

As a backend developer, I spend a lot of time working with JSON — API responses, logs, configs, exports.

Over time, I noticed a pattern:

• Many online JSON tools upload data to servers
• Large JSON files become slow or unusable
• Simple conversions (JSON → CSV / YAML) require multiple tools

So I decided to build a small side project for myself — a fast, client‑side JSON viewer that runs entirely in the browser.

Key Design Decisions

1. Everything Runs Client‑Side

No requests are sent to a server. This keeps data private and makes the tool extremely fast.

2. Handle Large JSON Gracefully

Instead of rendering everything at once, the viewer:

• Collapses nodes by default
• Renders incrementally
• Avoids blocking the UI thread

3. One Tool, Multiple Utilities

I didn’t want separate tools for every task, so I added:

• JSON validation
• JSON → CSV / Excel / YAML
• CSV → JSON
• JWT decoding
• Base64 encode/decode

What I Learned

• Client‑side tools can scale surprisingly well with the right rendering strategy
• Developers value privacy more than flashy UI
• Simplicity beats feature overload

Try It & Feedback

If you’re curious, you can try the tool here:

https://jsonviewertool.com

I’d genuinely love feedback from other developers:

• What would you improve?
• What’s missing?
• Any performance edge cases you’ve hit before?

Thanks for reading 🙌