Developer Utilities

Robust data transformers, security analyzers, and reference guides for software engineers.

Security & Privacy

API Key Generator

Generate secure, random API keys and secrets with custom prefixes.

Cipher Workshop

Encode and decode text with six historical ciphers — Caesar, ROT13, Atbash, Vigenère, Morse Code, and Bacon's binary steganography cipher.

Hash Generator

Generate MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes from text or files — entirely in your browser.

JWT Inspector

Decode and analyze JSON Web Tokens locally and securely.

Data Transformers

Base64 Converter

Encode and decode text or images to Base64 format instantly.

Coordinate Converter

Convert coordinates between DD, DMS, and UTM — with Haversine great-circle distance calculation.

Epoch Converter

Convert Unix timestamps to human-readable dates and vice versa.

Number Base Converter

Convert numbers between decimal, hex, binary, and octal — plus Base 36, Base 12, Maya Base 20, Babylonian Base 60, and Roman Numerals.

String Case Transformer

Transform text between camelCase, PascalCase, snake_case, kebab-case, and more — instantly.

A Bit of Whimsy

Black Cat's Yarn Chase

Take a break, entertain the void. Catch the falling yarn before it reaches the black cat.

Shiny Object Detector

A scientifically questionable diagnostic tool that measures the shininess of whatever new technology, framework, or side project you're currently distracted by.

Cron Reference

Moved — see Cron Workbench.

Developer Utilities

Cron Workbench

Parse any cron expression into plain English and explore the full syntax with a searchable field-by-field reference and common schedule presets.

Regex Workbench

Test and debug regular expressions live, with match highlighting, capture group tables, and multi-language code snippets.

Reference

DNS Record Reference

A searchable reference for every major DNS record type — with plain-English explanations, real-world usage examples, and example zone file syntax.

EPSG Code Reference

A searchable reference for the most common EPSG coordinate reference system codes — with proj4 strings, area of use, units, and descriptions for every entry.

Localization Reference

A searchable reference for locales, language codes, country codes, currency codes, timezones, date formats, and number formats — everything you need for i18n and l10n in one place.

MIME Type Reference

A searchable reference for every common MIME type — with file extensions, Content-Type header values, and usage notes for APIs, browsers, and servers.

Time Management

Focus Timer

A minimalist analog and digital countdown timer designed for focus, presentations, and classroom use.

Structural Formatters

GeoJSON Inspector

Paste, validate, format, and preview GeoJSON on an interactive map. Supports all geometry types.

HTML Formatter

Format, beautify, and minify HTML code instantly entirely within your browser.

JSON Formatter & Validator

Prettify, minify, and validate JSON strings with smart fix capabilities.

YAML Formatter & Validator

Format, validate, and convert YAML and JSON strings with ease.

Diagramming

Mermaid Diagram Composer

Write diagrams as code and see them rendered live — flowcharts, sequences, ERDs, and more.

Synthetic Generators

Mock Data Generator

Generate synthetic datasets for customers, products, financial transactions, and technical logs with controlled fuzziness for testing.