The latest articles on DEV Community by Ngoc Thien (@nnt25). https://dev.to/nnt25 https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F3949858%2F9f0f7594-0d50-4765-ada3-428eaa2025b7.png https://dev.to/nnt25 en Ngoc Thien Mon, 25 May 2026 03:20:13 +0000 https://dev.to/nnt25/building-a-privacy-first-self-hosted-network-diagnostic-tool-2ppj https://dev.to/nnt25/building-a-privacy-first-self-hosted-network-diagnostic-tool-2ppj <h1> NetCheck — Privacy-First Network Diagnostics </h1> <p>I just shipped a self-hosted network diagnostic tool after getting tired of random websites leaking my IP and tracking me.</p> <h2> What it does </h2> <p>DNS lookup, ping, traceroute, MTR, port check, SSL certificate inspection, WHOIS, reverse DNS, HTTP response checker, and request headers — all in one clean page.</p> <h2> The privacy angle </h2> <p><strong>Your origin IP never reaches the targets.</strong> All probes go through Globalping API, so targets see a third-party probe IP instead of yours. No tracking, no cookies, no analytics.</p> <h2> Tech stack </h2> <ul> <li>Backend: Python FastAPI</li> <li>Frontend: Vanilla HTML/CSS/JS (no framework, no build step)</li> <li>Deployment: Docker Compose (one command)</li> <li>License: AGPL v3</li> </ul> <h2> Live demo </h2> <p><a href="https://netcheck.nnt25.io.vn" rel="noopener noreferrer">https://netcheck.nnt25.io.vn</a></p> <h2> GitHub </h2> <p><a href="https://github.com/sudo-Penguin-Lalala/netcheck" rel="noopener noreferrer">https://github.com/sudo-Penguin-Lalala/netcheck</a></p> <p>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.</p> <p>Feedback and contributions welcome!</p> selfhosted privacy networking opensource