Tools you constantly need during development but hate searching for every time — solve it all in one place. Here are 10 essential IT calculators for everyday developer tasks, from formatting JSON to decoding JWTs.
📑 Table of Contents
1. Data Conversion Tools
The most frequently needed tools for API development, debugging, and data transfer.
Pretty-print or minify JSON. Also validates syntax and highlights errors instantly.
Encode or decode images, auth tokens, and binary data. Essential for Data URIs and API auth headers.
Safely encode URL parameters with special characters and decode percent-encoded strings back to readable form.
2. Security Tools
Password hashing, data integrity checks, and token-based authentication are core to any modern service.
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes at once. Useful for file integrity checks and checksum comparisons.
Decode JWT tokens to inspect Header, Payload, and Signature. Check expiration, issuer, and custom claims instantly.
3. Frontend Tools
Essential tools for converting CSS units and color formats during UI development.
Convert between px, rem, em, vw, and vh. Perfect for responsive design workflows.
Convert between HEX, RGB, RGBA, HSL, and HSV color formats. Great for translating Figma colors to code.
4. Server & Infrastructure Tools
Network configuration and file permission management tools for DevOps and full-stack developers.
Calculate network address, broadcast address, and host range from a subnet mask or CIDR notation.
Convert Linux file permissions between numeric (e.g. 755) and symbolic (e.g. rwxr-xr-x) notation.
5. Location-Based Tools
Calculate the straight-line distance between two GPS coordinates using the Haversine formula. Ideal for delivery radius and store locator features.
6. Pro Tips
💡 Maximize Your Productivity
Add 3-4 most-used tools to your browser bookmark bar for one-click access.
Quickly verify hash values or JWT structures included in pull requests.
All CalKit IT tools run entirely in your browser. No data is ever sent to a server.
Wrap-Up
A developer's day is a series of small conversion tasks. Instead of searching for a new tool each time, bookmark CalKit and handle everything in one place. All tools are free, require no sign-up, and process data entirely on the client side.