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.

Which developer tool do you need?

These utilities cover the small, recurring jobs that interrupt real work — reading an API response, converting a data file, decoding a token, scheduling a task. They pair naturally:

• Read or fix data: the JSON Formatter validates and pretty-prints JSON and pinpoints parse errors; the Code Formatter beautifies or minifies JS, CSS and HTML.
• Convert between formats: CSV → JSON for spreadsheet data, XML → JSON for legacy APIs and RSS/SOAP.
• Encode & decode: Base64 for data URIs and inspecting JWTs.
• Schedule & document: the Cron Generator builds and explains crontab expressions; the Markdown Editor previews README and docs as you type.

A typical flow: an API call returns something unexpected → format the response as JSON to see the structure → if it's actually XML or CSV, convert it → decode a Base64 or JWT field to read it. Everything runs in your browser, so code and data never leave your machine. The same utilities are available through the Tools Ninja API for automation and CI pipelines.

Frequently Asked Questions