Skip to main content
⚡ CRC Calc

CRC verification

CRC check value and “123456789”

Use the standard check string to verify an implementation and distinguish complete CRC models.

5 min read

Why 123456789 is used

CRC catalogues conventionally publish the result for the ASCII bytes of 123456789. This result is called the check value and provides a compact interoperability test.

31 32 33 34 35 36 37 38 39

What a matching check value proves

A matching check value strongly indicates that width, polynomial, Init, RefIn, RefOut, and XorOut are implemented consistently for that model. It does not by itself verify application-specific framing or transmitted byte order.

Recommended validation workflow

Test the check string, compare several known protocol frames, and verify empty input where a reference value is available. Automated tests should run for every preset whenever the engine changes.

Try it in the calculator

Change CRC parameters and compare standard algorithm results using the browser-based calculator.