JSON Formatter
Regex Tester
Timestamp Converter
UUID Generator
QR Code Generator
Lorem Ipsum
Markdown Editor
Code Minifier
Cron Generator
Code Diff
Case Converter
JWT Debugger
HTML Entities
Color Converter
About Developer Tools Calculators
Every developer needs a good set of tools. Our devtools section has utilities for JSON formatting, regex testing, JWT debugging, UUID generation, code diffing, and more.
Browse our curated collection of developer tools calculators below. Each tool includes detailed formulas, educational content, and real-time results. Use the 14 calculators in this category to make informed decisions, solve problems, and get accurate answers instantly.
Frequently Asked Questions
Is my data safe using these developer tools?
Yes. Every tool runs entirely client-side using JavaScript in your browser. No data — JSON, JWT tokens, code, or text — is ever sent to any server. You can safely work with production credentials and proprietary code without worrying about interception.
How do I decode a JWT token to see what is inside?
Paste your token into the JWT debugger and it decodes the base64 header and payload instantly, showing the algorithm, timestamps, and claims. Everything happens in your browser. Note that the payload is base64-encoded, not encrypted, so avoid putting sensitive data in JWT payloads.
How do I generate a UUID for my database or API?
The UUID generator creates v4 random UUIDs with one click. Choose uppercase or lowercase, with or without hyphens, and generate multiple IDs at once. Each UUID uses cryptographically strong random number generation suitable for production use.
What do the five fields in a cron expression mean?
Minute (0-59), hour (0-23), day of month (1-31), month (1-12), and day of week (0-7, where 0 and 7 are Sunday). For example, "30 6 * * 1-5" means weekdays at 6:30 AM. The cron generator builds these visually so you do not need to memorize the syntax.
How do I convert colors between HEX and RGB?
HEX uses six hex digits: first two for red, middle two for green, last two for blue. Convert each pair to decimal (FF becomes 255) to get RGB. The color converter does this instantly and also supports HSL and named CSS colors with live preview as you adjust values.