CRC Calculator

Compute checksums (Modbus CRC-16, CRC-32 and more).

READY

crc_calculator.tool

READY

Input mode

Hex bytesText (ASCII)

Input data

Hex bytes, e.g. 01 03 00 00 00 0A

CRC-16/MODBUS0xCDC5

Modbus frame (lo hi)C5 CD

CRC-16/CCITT-FALSE0x0428

CRC-320xDDEBE1C8

Byte count6

// HOW IT WORKS

A CRC (cyclic redundancy check) detects transmission errors by treating the data as a big number and taking the remainder of a polynomial division. The tool computes common CRCs such as Modbus CRC-16 and CRC-32.

Example

Modbus RTU frame 01 03 00 00 00 0A → CRC-16 0xCDC5 (low byte first on the wire: C5 CD).

Notes

The polynomial, initial value and bit order (reflected/normal) must match the protocol — Modbus uses 0xA001, init 0xFFFF, reflected.
A CRC detects errors but provides no security — it is not a cryptographic hash.

TOOLS

CRC Calculator

Compute checksums (Modbus CRC-16, CRC-32 and more).

READY

crc_calculator.tool

READY

Input mode

Hex bytesText (ASCII)

Input data

Hex bytes, e.g. 01 03 00 00 00 0A

CRC-16/MODBUS0xCDC5

Modbus frame (lo hi)C5 CD

CRC-16/CCITT-FALSE0x0428

CRC-320xDDEBE1C8

Byte count6

// HOW IT WORKS

Example

Modbus RTU frame 01 03 00 00 00 0A → CRC-16 0xCDC5 (low byte first on the wire: C5 CD).

Notes

The polynomial, initial value and bit order (reflected/normal) must match the protocol — Modbus uses 0xA001, init 0xFFFF, reflected.
A CRC detects errors but provides no security — it is not a cryptographic hash.