About CryptKit

Free cryptography tools for developers and privacy users.

Our Mission

CryptKit was built with a simple belief: security tools should be accessible, transparent, and private. Everyone deserves the ability to generate strong passwords, encrypt data, and understand cryptography — without sacrificing their privacy.

Why CryptKit Exists

Many online cryptography tools send your sensitive data to servers for processing. When you type a password into a "strength checker" on a typical website, that password travels across the internet to someone else's computer. This is a fundamental privacy violation.

CryptKit takes a different approach. Every tool runs entirely in your browser using the Web Crypto API and well-established JavaScript libraries. Your input never leaves your device. There is no server to compromise, no network request to intercept, and no database to breach.

What We Offer

  • Password Tools: Generate secure passwords, check strength, calculate entropy, and create memorable passphrases.
  • Encryption Tools: Encrypt and decrypt text using AES-256, the same standard used by governments and security professionals.
  • Hash Tools: Generate SHA-256, SHA-512, and other cryptographic hashes.
  • Encoding Tools: Encode and decode Base64, Hex, and other formats.
  • Authentication Tools: Generate HMAC codes, RSA key pairs, and explore BIP39 mnemonic generation (educational purposes).

Our Principles

  1. Privacy first: No PII collection, no user accounts. Your tool inputs stay in your browser. We use only anonymous analytics (GA4 with IP anonymization) and standard advertising (Google AdSense).
  2. Transparency: Our tools use well-known, audited algorithms. We don't hide how things work.
  3. Accessibility: All tools are free to use, work on any modern browser, and require no installation.
  4. Performance: Pages load fast, even on slow connections. We minimize JavaScript and avoid heavy frameworks.

Technology

CryptKit is built with:

  • Astro — Static site framework for fast, SEO-friendly pages.
  • React — For interactive tool components.
  • Tailwind CSS — For a clean, responsive design.
  • Web Crypto API — Browser-native cryptography for AES, SHA, and PBKDF2.
  • zxcvbn-ts — Password strength estimation.
  • BIP39 wordlist — For mnemonic phrase generation and validation.
  • EFF Wordlist — For Diceware passphrase generation.

Contact

Have questions, feedback, or suggestions? Visit our contact page to get in touch.