CRC Calculator (Cyclic Redundancy Check)
Compute CRC checksums for error detection. Supports common standards and custom parameters.
Hex ASCII
CRC Presets
CRC-32 Result
0xCBF43926
Data: "48656c6c6f" (hex)
Polynomial
0x04C11DB7
Width
32 bits
CRC (decimal)
3295232550
CRC Algorithm
CRC = (CRC << 1) XOR poly if MSB set
Final: CRC XOR finalXOR
Polynomial – divisor represented in binary (MSB omitted in hex notation)
Initial value – starting CRC register content
Final XOR – value XORed with CRC after processing
Reflect Input – reverse bit order of each input byte
Reflect Output – reverse bit order of final CRC
Initial value – starting CRC register content
Final XOR – value XORed with CRC after processing
Reflect Input – reverse bit order of each input byte
Reflect Output – reverse bit order of final CRC
People Also Ask
🔍 What is CRC and how does it work?
📊 Common CRC standards and their applications?
🔢 How to choose a polynomial for CRC?
🔄 What do "refin" and "refout" mean?
📏 What is the difference between CRC-8, CRC-16, CRC-32?
⚙️ How to implement CRC in software/hardware?
Understanding Cyclic Redundancy Check
CRC is an error-detecting code commonly used in digital networks and storage devices. It treats data as a binary polynomial and computes the remainder after division by a generator polynomial. The remainder (CRC) is appended to the data; the receiver recomputes and compares.
Why CRC?
CRC is simple to implement in hardware (shift registers and XOR gates) and can detect common errors like burst errors. It is widely used in Ethernet, USB, PNG, ZIP, and many other protocols.
Common CRC Polynomials
| Name | Polynomial (hex) | Width | Applications |
|---|---|---|---|
| CRC-8 | 0x07 | 8 | 1-Wire, Dallas/Maxim |
| CRC-16-IBM | 0x8005 | 16 | Modbus, USB |
| CRC-16-CCITT | 0x1021 | 16 | X.25, HDLC, Bluetooth |
| CRC-32 | 0x04C11DB7 | 32 | Ethernet, PNG, GZIP |
| CRC-32C | 0x1EDC6F41 | 32 | iSCSI, SCTP |
| CRC-64-ECMA | 0x42F0E1EBA9EA3693 | 64 | ECMA-182, DLT-1 |
Detailed FAQs
What is the difference between CRC and checksum?
Checksums (like sum of bytes) are simple but weak; CRCs use polynomial division and are much better at detecting common errors, especially burst errors. CRCs are preferred in many protocols.
How to verify CRC?
The receiver computes CRC over the received data (including the appended CRC). If the result is zero (for some variants) or matches a known residue, the data is considered intact. In this calculator, you can compute CRC for your data and compare.