CRC-32 Checksum
Compute the CRC-32 checksum used by ZIP, PNG and gzip. Detects accidental corruption — it is not a security hash.
Input
CRC-32
Enter something above to see the result.
A checksum, not a hash
CRC is built to catch accidents — a flipped bit on a wire, a truncated file — not attacks. It is fast enough to run on every packet, and it detects all single-bit errors and all burst errors shorter than its width.
It is trivially forgeable, though: anyone can craft different data with the same CRC. If an adversary is in the picture, you need SHA-256, not a checksum.
Frequently asked questions
Which CRC variant is this?
CRC-32 here is the IEEE 802.3 polynomial used by ZIP, gzip and PNG. CRC-16 is the ARC variant used by Modbus and many serial protocols.
Why is my CRC different from another tool?
CRC is a family, not one algorithm. Implementations differ in polynomial, initial value, bit reflection and final XOR — all of which change the result for the same input.