Security
Decode JWT tokens
jwt-decoderSecurity
Generate public/private key pairs for various cryptographic algorithms
key-pair-generatorSecurity
Generate JWT tokens with custom claims and algorithms
jwt-generatorValidation
Validate or generate numbers using the Modulus-11 (ISO 7064) check-digit algorithm with ISBN-10 (10..2), Norwegian-ID (3,7,6,1,8,9,4,5,2) and generic 2-7 weight schemes.
mod11-checksumSecurity
Generate or validate 12 to 24 word BIP39 mnemonic phrases with entropy and PBKDF2-HMAC-SHA512 seed output
mnemonic-bip39-generatorValidation
Validate license plate formats from multiple countries including China, USA, Japan, and more
license-plate-validatorCryptography
Hash the same input with MD5, SHA-1, SHA-256, SHA-512, BLAKE2b, and BLAKE3 at the same time and compare them side by side: output length, hex/Base64 digest, security status (broken / modern), and a relative speed benchmark. Great for teaching, choosing a hashing algorithm, or sanity-checking checksums.
hash-algorithm-comparatorSecurity
Compute an HMAC message-authentication signature over a message + shared secret using SHA-1/SHA-2/SHA-3/BLAKE2, or verify an incoming signature against the secret — with webhook presets for Stripe / Slack / GitHub and constant-time comparison
hmac-generator-verifierValidation
Validate International Securities Identification Numbers (ISO 6166 ISIN) with Luhn check-digit verification, country/issuer prefix and NSIN breakdown.
isin-validatorValidation
Audit heading structure from a live URL or pasted HTML, then flag skipped levels, multiple h1 usage, style-only heading abuse, and title metadata drift
heading-hierarchy-auditorValidation
Validate International Bank Account Numbers (IBAN)
iban-validatorValidation
Validate phone numbers from multiple countries including China, US, and more with detailed formatting and carrier info
global-phone-validator