Building a Privacy-First Self-Hosted Network Diagnostic Tool

NetCheck — Privacy-First Network Diagnostics

I just shipped a self-hosted network diagnostic tool after getting tired of random websites leaking my IP and tracking me.

What it does

DNS lookup, ping, traceroute, MTR, port check, SSL certificate inspection, WHOIS, reverse DNS, HTTP response checker, and request headers — all in one clean page.

The privacy angle

Your origin IP never reaches the targets. All probes go through Globalping API, so targets see a third-party probe IP instead of yours. No tracking, no cookies, no analytics.

Tech stack

• Backend: Python FastAPI
• Frontend: Vanilla HTML/CSS/JS (no framework, no build step)
• Deployment: Docker Compose (one command)
• License: AGPL v3

Live demo

https://netcheck.nnt25.io.vn

GitHub

https://github.com/sudo-Penguin-Lalala/netcheck

This is my first project and honestly a lot of it was built with Claude Code assistance, but every line is reviewed and it's production-ready.

Feedback and contributions welcome!

Comments

[Bhavin Sheth]

Really like the privacy-first approach here. Using third-party probes instead of exposing the user’s IP solves a problem most diagnostic tools ignore — impressive first project.