US routing number validator

Every check runs in this tab and nothing is uploaded. Be honest with yourself about what a pass means: the weighted sum of any nine digits is 0 to 81, so roughly one number in ten passes the checksum by luck alone. A pass means the digits are internally consistent with the ABA scheme; it does not prove a bank exists or owns that number. No bank-name directory is bundled, since a stale copy is worse than none; the Federal Reserve publishes the E-Payments Routing Directory for that. This tool also cannot decode FedACH participation or wire eligibility.