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CRC Online Calculator

Calculate various CRC checksums, supporting CRC-8, CRC-16 (Modbus, CCITT), CRC-32, CRC-64 and more algorithms. Supports text, hexadecimal, Base64 and file calculation.

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About CRC Algorithm

Cyclic Redundancy Check (CRC) is a powerful error-detecting code widely used in digital communication networks and storage devices to detect accidental changes to raw data. The system calculates a short checksum value based on polynomial division remainder for input data blocks and appends it to the data block.

When retrieving or receiving data, the checksum is recalculated. If the calculated result does not match the received checksum value, it indicates data corruption and error correction measures can be taken. CRC is designed to be easy to implement in binary hardware, easy to analyze mathematically, and particularly good at detecting common errors caused by transmission channel noise.

Supported CRC Standards

This tool implements various standard CRC algorithms widely used in industrial and network protocols. Each variant is defined by its polynomial, initial value, XOR output and reflection properties.

AlgorithmBit WidthPolynomialApplication
CRC-88 bit0x07Simple data verification, sensors
CRC-16/Modbus16 bit0x8005Modbus protocol, industrial communication
CRC-16/CCITT16 bit0x1021X.25, HDLC, Bluetooth
CRC-3232 bit0x04C11DB7ZIP, Ethernet, PNG
CRC-32C32 bit0x1EDC6F41iSCSI, SCTP, Btrfs
CRC-64/ECMA64 bit0x42F0E1EBA9EA3693ECMA-182, XZ compression

Common Use Cases

Network packet verification (Ethernet frames, IP packets)
File integrity verification (ZIP archives, PNG images)
Industrial communication protocols (Modbus RTU, fieldbus)
Storage system data verification (iSCSI, SSD controllers)
Embedded system data transmission (IoT sensors, USB communication)
Firmware and Bootloader integrity checks

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