CRC Checksum Calculator

Online CRC cyclic redundancy check calculation tool that supports multiple standard algorithms such as CRC-8/16/32, customizable parameters, and checksum verification for single and batch files.

Bug report

Browser execution mode: Your data is processed in your browser and is not uploaded to the server.

Speed and Stability: Processing speed depends on your device and browser. For large batch work, the desktop version may be more stable.

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If the online tool fails to load or run, try the desktop tool.https://tools.yikeaigc.com/

Tool Usage

Return to old version

Set algorithm and input first, then calculate the checksum

Common CRC-8, CRC-16/MODBUS, CRC-16/CCITT, and CRC-32 are listed first; switch to custom parameters for protocol adaptation.

Select parameters first Then add data Supports comparison check Batch results ZIP

Current Summary Not calculated

CRC-32 Default algorithm

32-bit Output Width

0 Batch files

0 History

Single CRC calculation

Select input type and CRC parameters, then click Calculate; enable “Show common algorithm comparison” to view multiple results.

Next: Batch Files

Input type

Text UTF-8 Hex Base64 File

Algorithm preset

Input data

Tip: set the algorithm first, then enter data and calculate.

Drag a file here, or click to select Files are read only on this page to calculate checksums

Output format

HEX DEC BIN

Bit width

Polynomial POLY

Initial Value INIT

Result XOR XOROUT

REFIN Input Reflected

REFOUT Output Reflected

Live calculation Show common algorithm comparison

Common Algorithm Comparison

Algorithm	Bit width	HEX	DEC	Parameter Summary

Batch File Verification

Select multiple files, then set the algorithm. Only the first 20 files are shown, but all files will be processed. Results can be downloaded as a ZIP report.

Next: Verify & Compare

Drag multiple files here, or click to select If file names repeat, exported reports auto-add numbers

Select batch algorithm

CRC-8 CRC-16 MODBUS CCITT CRC-32 MD5 SHA-1 SHA-256 SHA-512

CRC Output

Result sorting

Filter file name

Selected files0个

Waiting

Bulk Results

Checksum comparison

Enter a known CRC value and choose an algorithm, or let the tool try common algorithms by bit width to check for a match.

Next: history settings

Expected CRC

Verify algorithm

Input type

Text HEX File

Data to verify

Drag files here, or click to choose Compare file content with the expected CRC

Confirm the CRC parameters first if possible. If you only know the result, auto-detect will try common CRC-8, CRC-16, and CRC-32 presets one by one.

History & Settings

The last 50 single calculations are saved locally; common algorithms and formats can also be saved and restored next time.

Done

Save preferences

Save the current algorithm, input type, output format, and live calculation setting.

Calculation history

Instructions

Software Usage Instructions

Select a calculation method: You can use four sections: single calculation, batch file verification, verification comparison, and history settings.
Set the CRC algorithm: Select common algorithms such as CRC-32, CRC-16/MODBUS, CRC-16/CCITT-FALSE, and CRC-16/XMODEM from the algorithm presets. To adapt to a special protocol, choose custom parameters and fill in the width, POLY, INIT, XOROUT, REFIN, and REFOUT.
Enter the data to process: Single calculation supports text UTF-8, hexadecimal, Base64, and file input. Click “Load Example” to quickly view the calculation result for standard test data.
Run the calculation: After selecting the output format HEX, DEC, or BIN, click “Calculate CRC”. To compare multiple algorithms at the same time, check “Show common algorithm comparison”.
Batch file verification: Select multiple files, check the required CRC algorithms or MD5, SHA-1, SHA-256, and SHA-512 hash algorithms, then click “Start Batch Calculation”. The interface only displays some files, but all files will be covered during processing.
Download results: After batch processing is complete, click “Download Result ZIP” to obtain a complete verification report in CSV, TXT, and JSON formats. Duplicate file names will automatically have numbers appended for distinction.
Verification comparison: Enter a known CRC value, select a specified algorithm or automatic detection, then enter the data to verify to determine whether the checksum matches.
Save settings: Click “Save Settings” to save the current algorithm, input type, output format, and real-time calculation preferences. History records can be copied or cleared.

FAQ

A: CRC-16/MODBUS is a specific parameter combination of CRC-16 and is commonly used in MODBUS RTU communication. It typically uses the polynomial 0x8005, initial value 0xFFFF, input and output reflection, and its result may differ from other CRC-16 variants.

A: CRC results are determined jointly by parameters such as width, POLY, INIT, XOROUT, REFIN, and REFOUT. Even if they are all called CRC-16, different protocols may use different parameters. It is recommended to first confirm the protocol parameters, or use the verification comparison feature to find a matching algorithm.

A: Continuous input or separators such as spaces, commas, and hyphens are supported, for example 48656C6C6F, 48 65 6C 6C 6F, 0x48 0x65. The input must be in pairs to represent complete bytes.

A: Use automatic detection when you only know the target CRC value but are unsure of the exact algorithm. The tool will try common algorithms with the same bit width based on the CRC value length and list matching results or the actual calculated values.

A: Batch mode supports CRC algorithms such as CRC-8, CRC-16, CRC-16/MODBUS, CRC-16/CCITT-FALSE, and CRC-32, as well as MD5, SHA-1, SHA-256, and SHA-512 hash digests, making it suitable for file integrity checks.

A: First select a bit width of 8, 16, or 32 bits, then enter the POLY, INIT, and XOROUT hexadecimal values according to the protocol documentation, and set REFIN and REFOUT. After filling them in, you can use the standard test string 123456789 to verify whether the check value matches.