Check Digit Generator

About This Tool

The Check Digit Generator computes a checksum digit for a numeric string using standard algorithms. It is designed for developers and data professionals who need deterministic, testable identifiers for barcodes, account numbers, or internal IDs.
Conceptually, you provide a base numeric string and select an algorithm. The tool applies the algorithm's rules to produce a single check digit and, optionally, the full number with the check digit appended. It also supports validation by comparing an existing digit to the computed one.
Core features include multiple algorithms (Luhn, Verhoeff, Damm, Mod11), input validation, preservation of leading zeros, and batch processing. Use cases include generating test data for payment cards, shipping codes, and inventory IDs, or validating inputs in ETL pipelines.
Unique value lies in a single, programmable interface that documents the math, supports standard ISO/IEC references, and provides exact, numeric outputs suitable for automated testing and data quality checks.

Sign in to see all your usage