Developer Guides
Background for everyday development tasks: converting data formats, writing regular expressions, reading cron schedules, working with Unix timestamps, using hash functions, encoding data with Base64 and in URLs, reading JWTs, and generating passwords and UUIDs.
Converting Between JSON, CSV and YAML
What each format is good at and what can change during conversion.
Read guide →Regular Expression Basics
Character classes, quantifiers, groups, flags and backtracking.
Read guide →How to Read Cron Expressions
Unix, Spring, Quartz and AWS fields, special characters and time zones.
Read guide →Hash Functions Explained
Checksums, MD5 vs SHA-256, HMAC, and why hashing is not encryption.
Read guide →Base64, URL Encoding and JWT Explained
How Base64 and percent-encoding work, what a JWT contains, and why none of them hides data.
Read guide →Strong Passwords and UUIDs
Length, randomness, entropy, and the difference between UUID v4 and v7.
Read guide →Unix Timestamps Explained
Seconds or milliseconds, time zones, daylight saving and the 2038 limit.
Read guide →Use the Developer Tools
The guides explain the concepts; the tools run in your browser.
Frequently Asked Questions
Do I need to install anything to use the developer tools?
No. The tools run in a modern web browser, and the data you enter is processed on your device.
Can I use the results directly in production?
Review every result first. Formats, regex engines and schedulers differ between systems, so test the output where it will be used.