How to calculate CRC-32 online for Ethernet frames?

For Ethernet CRC-32 (IEEE 802.3), select the CRC-32/ISO-HDLC algorithm (also called CRC-32/PKZip or plain CRC-32). Input your frame data in HEX format. The CRC-32/ISO-HDLC uses polynomial 0x04C11DB7 with init 0xFFFFFFFF and reflected input/output. The check value for '123456789' is 0xCBF43926.

What is the AUTOSAR CRC calculator used for?

AUTOSAR CRC algorithms (CRC-8/AUTOSAR and CRC-32/AUTOSAR) are used in automotive software architectures for ECU communication integrity verification and memory protection, compliant with the AUTOSAR specification. CRC-8/AUTOSAR uses polynomial 0x2F; CRC-32/AUTOSAR uses polynomial 0xF4ACFB13.

How does a CRC calculator work?

A CRC (Cyclic Redundancy Check) calculator divides the input data polynomial by a generator polynomial using GF(2) arithmetic. The remainder is the CRC checksum. Key parameters include: the polynomial, initial value, input/output reflection, and XOR-out value. Different algorithms vary these parameters for their specific use cases.

How to calculate CRC-8/SAE-J1850 online?

Select CRC-8/SAE-J1850 from the algorithm list, input your data in ASCII or HEX format, and click Add Output. CRC-8/SAE-J1850 uses polynomial 0x1D with init value 0xFF and is widely used in automotive OBD-II and SAE J1850 vehicle network protocols.

What is CRC-16/CCITT and how is it different from CRC-16/XMODEM?

CRC-16/CCITT is an umbrella term that encompasses several variants. CRC-16/XMODEM (also known as CRC-16/CCITT-FALSE with init 0x0000) uses polynomial 0x1021, no reflection, and no XOR-out. CRC-16/IBM-3740 (also called CRC-16/CCITT-FALSE) uses the same polynomial but init value 0xFFFF. Always specify the exact variant to avoid ambiguity.

CRC Calculator

Q: How do I calculate a Modbus RTU CRC online?

Select CRC-16/MODBUS algorithm, set Input Method to HEX, enter your bytes (e.g. 0x01 0x03 0x00 0x00 0x00 0x0A), and set Byte Order to Little Endian. The result is the 2-byte CRC appended to your Modbus RTU frame. This tool supports online Modbus CRC calculation instantly.

Q: What is the CRC-17/CAN-FD polynomial?

The CRC-17/CAN-FD polynomial is x^17 + x^16 + x^14 + x^13 + x^11 + x^6 + x^4 + x^3 + x + 1, represented as 0x1685B in hexadecimal. The initial value is 0x00000 and there is no input or output reflection. This tool supports direct online calculation for CRC-17/CAN-FD.

Q: What is the CRC-21/CAN-FD polynomial?

The CRC-21/CAN-FD polynomial is x^21 + x^20 + x^13 + x^11 + x^7 + x^4 + x^3 + 1, represented as 0x102899 in hexadecimal. The initial value is 0x000000. This tool calculates CRC-21/CAN-FD checksums online.

Q: What is the CRC-64/WE check value for 123456789?

The CRC-64/WE check value for the ASCII string '123456789' is 0x62EC59E3F1A4F00A. You can verify this using this online CRC-64 calculator by selecting CRC-64/WE, entering '123456789' in ASCII mode.

Q: What is the difference between CRC-32 and CRC-32/MPEG-2?

Both CRC-32/ISO-HDLC (commonly called CRC-32) and CRC-32/MPEG-2 use polynomial 0x04C11DB7, but CRC-32/ISO-HDLC reflects input and output bytes and XORs the final result with 0xFFFFFFFF, while CRC-32/MPEG-2 does not reflect and uses no final XOR. Their check values for '123456789' differ: CRC-32 gives 0xCBF43926, CRC-32/MPEG-2 gives 0x0376E6E7.

Calculate CRC checksums with 100+ algorithms for data integrity verification

What is a CRC Calculator?

A CRC calculator (Cyclic Redundancy Check calculator) computes a short fixed-size checksum from any input data. CRC is the industry standard for error detection in digital networks, embedded systems, automotive buses (CAN, CAN-FD), storage devices, and industrial protocols (Modbus, PROFIBUS, DNP3). Every algorithm — from the simple CRC-8 to the robust CRC-64 — uses polynomial division in GF(2) to produce a checksum that catches single-bit errors, burst errors, and most multi-bit errors.

This tool is a free online CRC calculator and CRC decoder that requires no installation. Enter your data, select an algorithm such as CRC-32, CRC-16/MODBUS, CRC-8/SAE-J1850, or CRC-17/CAN-FD, and get the checksum instantly.

Modbus RTU CRC Calculator Online

The Modbus RTU protocol appends a 2-byte CRC-16/MODBUS checksum to every frame. This CRC uses polynomial 0x8005 (reflected as 0xA001), initial value 0xFFFF, reflected input and output, with no final XOR. The result is transmitted in little-endian order (low byte first).

How to Calculate Modbus RTU CRC Online

Set Input Method to HEX
Enter your frame bytes — for example: 0x01 0x03 0x00 0x00 0x00 0x0A
Select algorithm CRC-16/MODBUS
Set Byte Order to Little Endian and Byte Format to Separated
Click Add Output — the result is your 2-byte Modbus CRC

Example — Read Holding Registers request:

Input (HEX): 01 03 00 00 00 0A

CRC-16/MODBUS (Big Endian): 0x2BA1

CRC-16/MODBUS (Little Endian, separated): 0xA1 0x2B

Complete RTU frame: 01 03 00 00 00 0A A1 2B

CAN FD CRC Calculator — CRC-17/CAN-FD and CRC-21/CAN-FD

CAN FD (Controller Area Network Flexible Data-Rate) uses two CRC algorithms depending on frame length. Both are supported by this online CRC calculator.

CRC-17/CAN-FD — Polynomial, Parameters & Check Value

CRC-17/CAN-FD Parameters:

Polynomial: x¹⁷ + x¹⁶ + x¹⁴ + x¹³ + x¹¹ + x⁶ + x⁴ + x³ + x + 1
Hex polynomial: 0x1685B
Initial value: 0x00000
Input reflection: No | Output reflection: No
XOR-out: 0x00000
Check value ("123456789"): 0x04F03

Applied to CAN FD frames with up to 16 data bytes (DLC 0–12).

CRC-21/CAN-FD — Polynomial, Parameters & Check Value

CRC-21/CAN-FD Parameters:

Polynomial: x²¹ + x²⁰ + x¹³ + x¹¹ + x⁷ + x⁴ + x³ + 1
Hex polynomial: 0x102899
Initial value: 0x000000
Input reflection: No | Output reflection: No
XOR-out: 0x000000
Check value ("123456789"): 0x0ED841

Applied to CAN FD frames with more than 16 data bytes (DLC 13–15).

AUTOSAR CRC Calculator — CRC-8/AUTOSAR and CRC-32/AUTOSAR

AUTOSAR (AUTomotive Open System ARchitecture) defines specific CRC profiles for ECU inter-module communication and memory protection. Both CRC-8/AUTOSAR and CRC-32/AUTOSAR are available in this online calculator.

CRC-8/AUTOSAR

Polynomial: 0x2F
Initial value: 0xFF
XOR-out: 0xFF | No reflection
Check value ("123456789"): 0xDF
Use case: Short E2E protection frames in AUTOSAR communication stack

CRC-32/AUTOSAR

Polynomial: 0xF4ACFB13
Initial value: 0xFFFFFFFF
XOR-out: 0xFFFFFFFF | Reflected input & output
Check value ("123456789"): 0x1697D06A
Use case: AUTOSAR NvM (Non-Volatile Memory) block protection, long E2E profiles

Ethernet CRC-32 Calculator — IEEE 802.3 Frame Check Sequence

Ethernet uses CRC-32/ISO-HDLC (IEEE 802.3) as the Frame Check Sequence (FCS) appended to every Ethernet frame. It is the most widely used CRC algorithm — also found in ZIP, PNG, gzip, and many other file formats.

CRC-32/ISO-HDLC (Ethernet CRC-32) Parameters:

Polynomial: 0x04C11DB7
Initial value: 0xFFFFFFFF
XOR-out: 0xFFFFFFFF | Reflected input & output
Check value ("123456789"): 0xCBF43926

Also known as: CRC-32/PKZip, CRC-32b, CRC-32/ADCCP

To calculate the CRC-32 for an Ethernet frame online: select CRC-32/ISO-HDLC, enter frame payload in HEX, set Big Endian output. The result is the 4-byte FCS value.

CRC-64 Online Calculator — CRC-64/WE, CRC-64/XZ, CRC-64/ECMA-182

CRC-64 provides 64-bit checksums for large data sets such as database records, storage systems, and network payloads. This online calculator supports all major CRC-64 variants.

CRC-64 Check Values for "123456789":

CRC-64/WE: 0x62EC59E3F1A4F00A
CRC-64/XZ (also CRC-64/GO-ECMA): 0x995DC9BBDF1939FA
CRC-64/ECMA-182: 0x6C40DF5F0B497347
CRC-64/GO-ISO: 0xB90956C775A41001
CRC-64/MS: 0x75D4B74F024ECEEA
CRC-64/REDIS: 0xE9C6D914C4B8D9CA

How This Online CRC Calculator Works

This tool calculates CRC checksums entirely in your browser using WebAssembly (Rust compiled to WASM). No data is sent to any server — your input stays private. All 100+ CRC algorithms use the industry-standard implementations from the crc crate with verified test vectors.

Key Features

100+ CRC algorithms:CRC-3 through CRC-64 — every algorithm from the Catalogue of CRC algorithms
Multiple input formats:ASCII text, HEX (0x / \x / raw), Binary (0b prefix), Decimal, Octal
Flexible output:HEX, Decimal, Binary, Octal — with prefix style, endianness, and byte separation options
Multiple simultaneous outputs:Compare up to 10 algorithms side-by-side on the same input
Persistent settings:Configuration auto-saved to browser local storage
Real-time calculation:CRC computed on every keystroke with full error validation

Supported Input Format Examples

HEX input — all formats accepted:

With 0x prefix: 0x01 0x02 0x03 0x04
Escape sequence: \x01\x02\x03\x04
Short prefix: x01x02x03x04
Raw hex pairs: 01 02 03 04
Mixed: 0x01 \x02 x03 04

Binary input:

0b01001000 0b01100101 or 01001000 01100101

Decimal input (0–255 per byte):

72 101 108 108 111 → "Hello"

CRC Algorithm Quick Reference

The tables below list the most commonly used CRC algorithms with their parameters and primary applications. Use this as a CRC decoder reference when you need to identify or verify an algorithm.

CRC-8 Algorithms

Algorithm	Polynomial	Init	Check (123456789)	Application
CRC-8/AUTOSAR	0x2F	0xFF	0xDF	Automotive ECU, AUTOSAR E2E
CRC-8/SAE-J1850	0x1D	0xFF	0x4B	OBD-II, SAE J1850 vehicle network
CRC-8/MAXIM-DOW	0x31	0x00	0xA1	1-Wire, Dallas/Maxim sensors
CRC-8/SMBUS	0x07	0x00	0xF4	SMBus, I2C
CRC-8/BLUETOOTH	0xA7	0x00	0x26	Bluetooth HEC

CRC-16 Algorithms

Algorithm	Polynomial	Init	Check (123456789)	Application
CRC-16/MODBUS	0x8005	0xFFFF	0x4B37	Modbus RTU industrial protocol
CRC-16/XMODEM	0x1021	0x0000	0x31C3	XMODEM, YMODEM file transfer
CRC-16/IBM-3740	0x1021	0xFFFF	0x29B1	CRC-CCITT (false init variant)
CRC-16/USB	0x8005	0xFFFF	0xB4C8	USB token and data packets
CRC-16/DNP	0x3D65	0x0000	0xEA82	DNP3 (power systems / water utilities)
CRC-16/PROFIBUS	0x1DCF	0xFFFF	0xA819	PROFIBUS fieldbus

CRC-32 Algorithms

Algorithm	Polynomial	Check (123456789)	Application
CRC-32/ISO-HDLC	0x04C11DB7	0xCBF43926	Ethernet, ZIP, PNG, gzip — most common CRC-32
CRC-32/MPEG-2	0x04C11DB7	0x0376E6E7	MPEG-2 transport streams, AAC
CRC-32/AUTOSAR	0xF4ACFB13	0x1697D06A	Automotive AUTOSAR NvM
CRC-32/BZIP2	0x04C11DB7	0xFC891918	BZIP2 compression
CRC-32/ISCSI	0x1EDC6F41	0xE3069283	iSCSI (Castagnoli CRC)

Frequently Asked Questions — CRC Calculator

How do I calculate a Modbus RTU CRC online?

Select CRC-16/MODBUS, set Input Method to HEX, enter your bytes (e.g. 01 03 00 00 00 0A), set Byte Order to Little Endian, then click Add Output. The two result bytes are appended to your Modbus frame in the order shown. See the Modbus CRC section above for a full example.

What is the CRC-17/CAN-FD polynomial?

The CRC-17/CAN-FD polynomial is x¹⁷ + x¹⁶ + x¹⁴ + x¹³ + x¹¹ + x⁶ + x⁴ + x³ + x + 1 (hex 0x1685B). Init value: 0x00000, no reflection, no XOR-out. Check value for "123456789": 0x04F03.

What is the CRC-21/CAN-FD polynomial?

The CRC-21/CAN-FD polynomial is x²¹ + x²⁰ + x¹³ + x¹¹ + x⁷ + x⁴ + x³ + 1 (hex 0x102899). Init value: 0x000000, no reflection, no XOR-out. Check value for "123456789": 0x0ED841.

Why do I get different CRC results from different tools?

CRC algorithms sharing a short name (like "CRC-16" or "CRC-32") can differ in polynomial, initial value, XOR-out, or bit reflection. Always verify which exact variant you need. This tool uses the official algorithm names from the Catalogue of CRC Algorithms (Greg Cook) and computes results using verified test vectors.

What is the CRC-64/WE check value for 123456789?

The CRC-64/WE check value for ASCII input "123456789" is 0x62EC59E3F1A4F00A. You can verify this directly using this tool: select CRC-64/WE, enter 123456789 in ASCII mode, and click Add Output.

How is CRC-16/XMODEM different from CRC-16/CCITT?

"CRC-16/CCITT" is ambiguous. CRC-16/XMODEM uses polynomial 0x1021 with init 0x0000, no reflection. CRC-16/IBM-3740 (often called CRC-CCITT false) uses the same polynomial but init 0xFFFF. Always use the precise algorithm name to avoid mismatches in protocol implementations.

Can CRC detect all errors?

CRC guarantees detection of all single-bit errors, all double-bit errors within the CRC span, all burst errors up to CRC width, and all odd-number-of-bit errors when the generator has (x+1) as a factor. It does not guarantee detection of all multi-bit errors — for security-critical applications, use cryptographic hashes (SHA-256, HMAC) instead.

What is the difference between CRC-32 and CRC-32/MPEG-2?

Both use polynomial 0x04C11DB7, but CRC-32/ISO-HDLC (common CRC-32) reflects input/output and XORs output with 0xFFFFFFFF, while CRC-32/MPEG-2 does not reflect and has no XOR-out. Check values for "123456789": CRC-32 = 0xCBF43926, CRC-32/MPEG-2 = 0x0376E6E7.

How to calculate CRC for a hex string like 0x0B 0x86 0x03?

Set Input Method to HEX and enter 0x0B 0x86 0x03 (or 0B 86 03). Select your target algorithm (e.g. CRC-16/MODBUS for Modbus frames) and click Add Output. The tool accepts all common hex formats including 0x prefix, \x escape, and raw pairs.

Which CRC Algorithm Should I Use?

Ethernet / ZIP / PNG / gzip:CRC-32/ISO-HDLC (standard CRC-32)
Modbus RTU:CRC-16/MODBUS (little-endian, polynomial 0x8005)
CAN bus:CRC-15/CAN
CAN FD (≤16 bytes):CRC-17/CAN-FD
CAN FD (>16 bytes):CRC-21/CAN-FD
AUTOSAR ECU:CRC-8/AUTOSAR or CRC-32/AUTOSAR
USB packets:CRC-16/USB or CRC-5/USB
Bluetooth BLE:CRC-24/BLE
XMODEM / YMODEM file transfer:CRC-16/XMODEM
iSCSI storage:CRC-32/ISCSI (Castagnoli)
Dallas 1-Wire sensors:CRC-8/MAXIM-DOW
Large files / databases:CRC-64/XZ or CRC-64/WE
MPEG-2 video streams:CRC-32/MPEG-2
OpenPGP:CRC-24/OPENPGP

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Input Settings

Input Method

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Algorithm

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ASCII Mode

Any text characters are supported

Processed Data

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CRC-32/ISO-HDLC Result

Click to copy

Algorithm:

Format:

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Bytes: