Security Tools
Free developer tools for JWT, cryptography, and security. Pick a tool below — everything runs locally in your browser.
JWT Tools
JWT Secret Generator
Generate cryptographically secure JWT secrets with RFC 7518 minimum lengths. Output as base64url, hex, or base64 — plus one-click Copy for .env. Runs entirely in your browser.
Use NowJWKS Viewer
Paste a JWKS or JWK to inspect kid, kty, alg, and key size. Export RSA/EC public keys to PEM, strip private fields, or build a JWKS from public PEM — free, client-side.
Use NowJWT Decoder
Decode JWT tokens online without a secret. Inspect header, payload, expiration, and claims. Free client-side JWT decoder.
Use NowJWT Token Validator
Validate JWT tokens, verify signatures, check expiration, and inspect header and payload claims. Free online JWT debugger tool.
Use NowJWT Encoder
Create and sign JWT tokens with custom headers, payloads, and secrets. Supports HS256 signing. Free browser-based JWT builder.
Use NowJWT Fuzzer
Generate JWT security test variants: tampered payloads, alg:none, expired tokens. Educational JWT fuzzer for development.
Use NowKeys & Crypto
RSA Key Generator
Generate RSA 2048 and 4096-bit public/private key pairs in PEM format. Free browser-based RSA key generator for RS256 JWT signing.
Use NowHash Generator
Generate MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes instantly in your browser. No data uploaded. Free cryptographic hash tool.
Use NowAES Key Generator
Generate AES-128, AES-192, and AES-256 encryption keys online. Export as hex or Base64. Free client-side AES key generator.
Use NowHMAC Generator
Generate HMAC-SHA256, HMAC-SHA384, and HMAC-SHA512 online. Free client-side HMAC generator for API authentication and JWT signing.
Use NowGenerators
Session / CSRF Secret Generator
Generate cryptographically secure session and CSRF secrets (32–64 bytes). Output as base64url, hex, or base64 — plus Copy for .env. Client-side only.
Use NowPassphrase Generator
Generate memorable high-entropy passphrases from a 2048-word list. Choose word count, separator, and options. Cryptographically random, client-side only.
Use NowAPI Key Generator
Generate secure API keys in UUID, hex, alphanumeric, or Base64 format with custom prefixes. Cryptographically random. Free tool.
Use NowPassword Generator
Generate strong random passwords with custom length and character sets. Cryptographically random, client-side only. Free password generator.
Use NowUUID Generator
Generate RFC 4122 compliant UUID v1, v4, and v5 values. Bulk generate up to 100 UUIDs at once. Free browser-based UUID generator.
Use NowEncoding
Base64 Encoder Decoder
Encode or decode Base64 strings with full UTF-8 support. Client-side only, instant results. Free online Base64 converter tool.
Use Now