Practical, example-driven tutorials for everyday development tasks. Each guide links to a free tool so you can try the technique on your own data.
Pretty-print, minify and sort JSON online or in code. Covers indentation choices, key sorting, common syntax errors and handling large files safely.
Updated Oct 9, 20266 min readUses: JSON Formatter
Decode a JSON Web Token's header and payload by hand or in code, read exp, nbf and iat claims, and see why only signature verification proves a token valid.
Updated Oct 9, 20266 min readUses: JWT Decoder
A practical walkthrough of REST API testing: HTTP methods and idempotency, status code classes, request headers, CORS preflight and repeatable checks in code.
Updated Oct 9, 20266 min readUses: API Tester
Translate curl flags like -X, -H, -d, --json, -F and -u into JavaScript fetch and Axios code, with the defaults and gotchas that make conversions go wrong.
Updated Oct 9, 20266 min readUses: cURL to Code
Understand UUID versions under RFC 9562, compare random v4 with time-ordered v7 for database keys, and generate UUIDs in JavaScript, Python, SQL and the shell.
Updated Oct 9, 20265 min readUses: UUID Generator
Find and fix JSON syntax errors, catch duplicate keys and big-number pitfalls, and validate structure with JSON Schema in JavaScript, Python and CI pipelines.
Updated Oct 9, 20266 min readUses: JSON Validator
Learn the five cron fields, special characters and day-of-month/day-of-week OR rules, with 18 tested schedule examples and tips on timezones and DST.
Updated Oct 9, 20266 min readUses: Cron Generator