Validation

Validate 8-digit EAN-8 / GTIN-8 product barcodes with check-digit verification, GS1 country prefix and packaging breakdown.

Security

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

Validation

Validate International Securities Identification Numbers (ISO 6166 ISIN) with Luhn check-digit verification, country/issuer prefix and NSIN breakdown.

Validation

Validate or generate numbers using the Luhn algorithm (mod-10). Works for credit cards, IMEI, IMEISV, SIN, NPI and any custom Luhn-based identifier.

Validation

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.

Validation

Validate 9-digit US ABA bank routing numbers (RTN) with MICR check-digit verification, Federal Reserve district lookup and ABA institution breakdown.

Validation

Validate 7-character UK/Irish SEDOL securities identifiers with weighted mod-10 check-digit verification and SEDOL-7 structure breakdown.

Security

Generate RFC 6238 TOTP (time-based, 6/8 digits, 30/60s step) and RFC 4226 HOTP (counter-based) one-time passwords from a base32 shared secret, fully offline with HMAC-SHA1/256/512, plus an otpauth:// URI for importing into Google Authenticator / Authy

Validation

Validate OpenAPI 3.0/3.1 and Swagger 2.0 documents structurally: required fields, path/operation completeness, response codes, $ref resolution, operationId uniqueness, and component integrity

Security

Generate or validate 12 to 24 word BIP39 mnemonic phrases with entropy and PBKDF2-HMAC-SHA512 seed output

Validation

Lint robots.txt syntax, flag risky rules, and test important URLs before you ship crawler directives

Security

Generate Ed25519 or X25519 keypairs from random or deterministic seed text, then sign or verify messages