Developer Utilities

A hub of everyday developer utilities

This page bundles the small, fiddly conversions and validations developers reach for many times a day into one place. Everything runs directly in your browser — nothing you type is sent to a server — so it is fast, private and works even on flaky connections. Below is what each tool does and when it is useful.

What's inside

• Timestamp Converter — turn a Unix timestamp into a human-readable date and back again, in both local time and UTC. Essential when you are reading logs, debugging APIs or working with database records that store epoch seconds or milliseconds.
• Color Picker & Converter — pick a color and convert it instantly between HEX, RGB and HSL. Useful for translating a value from a design mockup into the exact format your CSS or code needs.
• Base Converter — convert numbers between binary, octal, decimal and hexadecimal. A quick helper for bitmasks, permissions, color values and low-level debugging.
• Email Validator — check whether an email address is syntactically valid before you rely on it, catching typos and malformed input at a glance.
• Credit Card Validator — verify a card number's format using the Luhn checksum and identify the likely card network. It only checks the maths of the number; it never contacts a bank or processes a payment.

Frequently Asked Questions