Compute cyclic redundancy checks across 18 standard CRC algorithms in one pass — CRC-8 (SMBus, MAXIM, ROHC), CRC-16 (ARC, CCITT-FALSE, KERMIT, MODBUS, USB, XMODEM, GENIBUS, MCRF4XX), and CRC-32 (IEEE 802.3, BZIP2, MPEG-2, POSIX, Castagnoli/iSCSI, JAMCRC). Paste ASCII text or hex bytes; every result updates as you type.
Click any hex value to copy it. The check value for the ASCII string "123456789" is the canonical test vector for every CRC variant listed in the Rocksoft / Catalog of CRCs.
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A cyclic redundancy check treats data as a polynomial over GF(2) and divides it by a fixed generator polynomial; the remainder is the CRC. Different applications standardize different polynomials, bit/byte reflection modes, initial values, and final XOR values — the Catalog of CRC algorithms by Greg Cook lists 100+ variants. The common ones implemented here:
0x04C11DB7, reflected).0x1EDC6F41).