$ ls -lh ./tools
// client-side only. nothing you type here ever leaves your browser.
# utilities
JWT Decoder
Decode a JWT's header and payload. No signature verification, no network calls.
run ./jwt-decoder →Cron Parser
Human-readable explanation of a cron expression, plus its next run times.
run ./cron-parser →Unix Timestamp Converter
Convert between Unix epoch and human-readable dates, local and UTC.
run ./timestamp-converter →# data
SQL Analytics (DuckDB)
Query CSV, JSON, Parquet or raw log files with SQL, right in your browser. Includes a sample nginx log and ready-made analysis queries.
run ./sql-analytics →# visualizers
SQL Map
Drop PostgreSQL or IBM Db2 scripts (a pg_dump, a db2look export, migrations) and get diagrams and a catalogue of everything in them: tables and how they reference each other, views, functions and what they read and write, triggers step by step, types, indexes, row security and cron jobs. Works on phones too. Your SQL is never uploaded.
run ./sql-map →# templates
IT spreadsheet templates
Not a browser tool, but in the same spirit: Excel + Google Sheets trackers for SSL/domain expiry, IT assets & licences, incidents with MTTR, and on-call rotas. Plain formulas, no macros. From $12.
ls ./shop →// looking for challenges? they moved to ./practice.