CRC Calculator
Compute checksums (Modbus CRC-16, CRC-32 and more).
READY
crc_calculator.tool
READY
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.