Tools
Small utilities that make the ideas in the articles visible. Every tool runs entirely in your browser; nothing you type is sent to a server.
AI and LLMs
Token counter
Count tokens with a real tokenizer and see how much of a context window your text fills.
Chunking playground
Split your own text with different RAG chunking strategies and compare the pieces.
AI security
Prompt injection checker
See which common injection patterns a simple filter spots, and learn why filters are not enough.
Networking
IPv4 subnet calculator
Network, broadcast, host range and mask for any IPv4 address in CIDR notation.
Web and encoding
Security headers analyzer
Paste a site's response headers and get a checklist of missing or weak protections.
JWT decoder
Decode a JSON Web Token's header and payload and spot common mistakes. Decoding only; no verification.
Base64 encoder and decoder
Encode and decode Base64 and Base64url with correct handling of Unicode text.
Hash generator
SHA-1, SHA-256, SHA-384 and SHA-512 hashes of text, computed with your browser's Web Crypto.