The latest articles on DEV Community by DarkenAmber (@darkenamber). https://dev.to/darkenamber 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%2F3968767%2Fb4ec3020-523e-4203-b89f-3afb3bd14810.png https://dev.to/darkenamber en DarkenAmber Fri, 05 Jun 2026 05:47:30 +0000 https://dev.to/darkenamber/i-built-36-offline-itsecurity-tools-in-a-single-html-file-no-npm-no-backend-no-tracking-1fn0 https://dev.to/darkenamber/i-built-36-offline-itsecurity-tools-in-a-single-html-file-no-npm-no-backend-no-tracking-1fn0 <p><a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fx6ayjk6anur1sz1apkp2.png" class="article-body-image-wrapper"><img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Fx6ayjk6anur1sz1apkp2.png" alt=" " width="800" height="388"></a><br> <a href="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Frmlet1sqz0xo9dklyjs6.png" class="article-body-image-wrapper"><img src="https://media2.dev.to/dynamic/image/width=800%2Cheight=%2Cfit=scale-down%2Cgravity=auto%2Cformat=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Farticles%2Frmlet1sqz0xo9dklyjs6.png" alt=" " width="799" height="385"></a>I'm an engineer from Baku. I build things as a hobby.</p> <p>I got tired of opening 5 different sites every time I needed to check <br> a certificate, calculate subnets, or encrypt something. Each one had <br> ads, wanted my email, and made me wonder where my data went.</p> <p>So I started building. One tool. Then another. 36 tools later — here we are.</p> <h2> The unusual part </h2> <p>It's a single HTML file. 460KB. No npm. No build step. No server.<br> </p> <div class="highlight js-code-highlight"> <pre class="highlight shell"><code>open index.html </code></pre> </div> <p>That's the entire setup. Works offline, works on any machine.</p> <h2> What's inside </h2> <p>The usual stuff — JSON, JWT, Base64, UUID, QR codes, Regex.</p> <p>But also things I haven't seen elsewhere as offline tools:</p> <ul> <li> <strong>Packet Analyzer</strong> - paste Wireshark hex dump, get full protocol breakdown</li> <li> <strong>CIDR Aggregator</strong> - merge subnets, export as Cisco ACL or iptables</li> <li> <strong>Config Diff</strong> - syntax-aware diff for Cisco IOS, Juniper, nginx</li> <li> <strong>HTTP Headers Analyzer</strong> - security grade A+ to F</li> <li> <strong>AES-GCM encryption, SSH/RSA keys</strong> - all via Web Crypto API</li> </ul> <h2> Honest note </h2> <p>Built with heavy AI assistance (Claude). My ideas, my decisions, <br> my testing. Claude wrote the code. Being upfront about this.</p> <h2> Links </h2> <p>Demo: <a href="https://darkenamber.github.io/DarkenAmber-it-tools" rel="noopener noreferrer">https://darkenamber.github.io/DarkenAmber-it-tools</a><br> GitHub: <a href="https://github.com/DarkenAmber/DarkenAmber-it-tools" rel="noopener noreferrer">https://github.com/DarkenAmber/DarkenAmber-it-tools</a></p> <p>Feedback welcome.</p> opensource javascript security networking