Is my data sent to any server?

No. All computation happens entirely in your browser using JavaScript. Your input never leaves your device.

Which CRC-16 variant does this use?

This uses CRC-16/IBM (also called CRC-16/ARC): polynomial 0x8005, reflected input/output, initial value 0x0000, no final XOR. This is the variant used by Modbus and many industrial protocols.

Which CRC-32 variant does this use?

This uses CRC-32/ISO-HDLC (also called CRC-32b): polynomial 0xEDB88320 (reflected 0x04C11DB7), initial value 0xFFFFFFFF, final XOR 0xFFFFFFFF. This is the same variant used by zlib, gzip, and PNG.

Which CRC-8 variant does this use?

This uses CRC-8/SMBUS: polynomial 0x07, non-reflected, initial value 0x00, no final XOR. This is the most common baseline CRC-8 variant.

What is the hex input format?

Enter bytes as hexadecimal pairs, separated by spaces, commas, or nothing — for example: "DE AD BE EF" or "deadbeef" or "DE,AD,BE,EF". Odd-length sequences are rejected with an error.

Can CRC be used for cryptographic security?

No. CRC is a checksum for error detection, not a cryptographic hash. It is straightforward to craft collisions. For security use SHA-256 or SHA-3.

CRC Calculator

Name: CRC Calculator
Availability: InStock
Author: Nham Vu

Compute CRC-8, CRC-16, and CRC-32 checksums from text or raw hex bytes, with results in hex, decimal, and binary.

Input

Input Mode

Data

CRC Algorithm

CRC-16/IBM — poly 0x8005, init 0x0000 (Modbus, LIN bus)

0 bytes

Result

Enter data on the left to compute a checksum.

All Algorithms at a Glance

Enter data above to see all checksums.

Algorithm	Hex	Decimal

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Summary

Compute CRC-8, CRC-16, and CRC-32 checksums from text or raw hex bytes, with results in hex, decimal, and binary.

How it works

Choose the input mode — plain text (UTF-8) or raw hex bytes (e.g. DE AD BE EF).
Type or paste your data into the input field.
Select the CRC variant: CRC-8, CRC-16 (IBM), or CRC-32 (ISO-HDLC / zlib).
The checksum updates instantly and is shown in hex, decimal, and binary.
Click any Copy button to copy the desired representation to your clipboard.

Use cases

Verify data integrity after transmission over serial or network links.
Generate test vectors for embedded firmware that uses CRC checks.
Debug communication protocols that include CRC fields (e.g. Modbus CRC-16).
Cross-check CRC output from different programming languages or libraries.
Validate the CRC of a small configuration blob or binary patch segment.
Learn how different CRC polynomials produce different results for the same input.
Quickly compute the CRC of ASCII command strings before sending over UART.
Check that a manually assembled hex byte sequence has the expected checksum.

Frequently Asked Questions

Last updated: 2026-06-09 · Reviewed by Nham Vu