Tools

Small developer tools

Everything here runs entirely in your browser. Nothing you paste in is ever sent anywhere - open your browser's network tab and check for yourself.

Command explainer

Paste a shell command and get a plain-English breakdown of every flag - handles combined short flags, pipes, and &&.

Cron expression explainer

Turn a 5-field cron expression into plain English plus the next 5 run times in your local timezone.

chmod calculator

Flip checkboxes or type octal/symbolic notation - converts between all three, plus setuid/setgid/sticky.

Regex tester

Live-highlighted matches and a capture-group table, with a timeout guard against catastrophic patterns.

JWT decoder

Decode a JWT's header and payload, with exp/iat/nbf shown as human dates. Does not verify signatures.

JSON <-> YAML

Convert between JSON and YAML in either direction, plus format or minify JSON with line/col error messages.

LLM token & cost calculator

Paste text or enter token counts to see exact OpenAI token counts (estimated for Claude/Gemini) and the cost per request or per month, against a verified per-1M-token price table.

RAG chunking visualiser

Paste text and compare fixed-character, fixed-token, sentence-aware, and paragraph/recursive chunking strategies as coloured blocks, with overlap highlighted and size stats.