CRC-16 Generator
Generate a CRC-16 checksum of any text or file, instantly inside your browser.
What is CRC-16?
CRC-16 is a cyclic redundancy check that takes any input — text or a file — and produces a fixed 16-bit checksum, shown as 4 hexadecimal characters. It's commonly used in serial protocols like Modbus and in older file formats where a compact checksum is enough to catch accidental transmission errors. Like all CRC algorithms, it is fast but not cryptographically secure.
This tool computes the checksum of typed text or an uploaded file directly using the standard CRC-16/ARC polynomial, entirely inside your browser.
GuideHow to use it
How the checksum is calculated
The input is read as raw bytes — either the UTF-8 bytes of typed text, or the exact bytes of an uploaded file — and processed through the selected CRC polynomial entirely in JavaScript, using a precomputed lookup table for speed.
Why it helpsFeatures & benefits
Why this runs entirely in your browser
Files and text checksummed here can contain private data, so nothing is uploaded to a server. The CRC algorithm runs entirely in JavaScript locally in the tab, which means it keeps working offline once the page has loaded.
Common uses
Verifying a downloaded file wasn't corrupted in transit, checking data integrity in embedded and serial protocols, validating archive contents, or working through a computer science exercise on error-detecting codes.
Frequently asked questions
A few things people usually want to know before trusting the numbers.
No. CRC-16 is designed to detect accidental corruption, not deliberate tampering. Use SHA-256 or SHA-512 for security-sensitive integrity checks.
16 bits, shown as 4 hexadecimal characters.
Yes. Switch to File mode and upload or drag a file — its exact bytes are checksummed, not just its text content.
Yes. Clicking a different algorithm switches the page while keeping the text or file you've already entered.
No. All checksumming happens locally in your browser. Nothing typed, pasted, or uploaded here is sent to a server, stored, or shared.