Security Tools

Free developer tools for JWT, cryptography, and security. All processing runs in your browser — no data is sent to any server.

JWT Tools

Generate cryptographically secure random keys from 32 to 512 bits of entropy.

Verify JWT signatures, check expiration, and inspect header and payload claims.

Build and sign JWT tokens with custom headers, payloads, and HS256 secrets.

Compute MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes client-side.

Generate secure API keys in UUID, hex, alphanumeric, or Base64 format.

Create strong random passwords with customizable length and character sets.

Generate RFC 4122 compliant UUIDs in v1, v4, and v5 formats — up to 100 at once.

Encode and decode Base64 strings with full UTF-8 support.