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
JWT Secret Generator
Generate cryptographically secure JWT secret keys from 128 to 512 bits. Supports HS256, HS384, and HS512. Runs entirely in your browser.
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 Decoder
Decode JWT tokens online without a secret. Inspect header, payload, expiration, and claims. Free client-side JWT decoder.
Use NowJWT Fuzzer
Generate JWT security test variants: tampered payloads, alg:none, expired tokens. Educational JWT fuzzer for development.
Use NowCryptographic Tools
Hash 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 NowAPI Key Generator
Generate secure API keys in UUID, hex, alphanumeric, or Base64 format with custom prefixes. Cryptographically random. Free tool.
Use NowRSA 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 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 NowPassword & Identity
Password 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 Tools
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