Algorithms

CRC-32

The error-detection checksum in every ZIP and PNG and gzip. Four bytes and useless against an attacker
IDcrc3219 / 24non-cryptographic · 32-bit
Hash / Non-cryptographic

CRC-32

The checksum in every ZIP, PNG and gzip.

Digest
32-bit · 4 bytes
HMAC
no key mode
Security
NOT for security: error-detection checksum only
Family
4 in non-cryptographic
1 option, 0 required

Sample

hex
0d4a1185
base64
DUoRhQ==

Options

encodingstring
default hex
Output encoding: hex, base64, base64url, binary

Access

Createcreate("crc32")
CLIhashes crc32 'hello world'
Tryplayground with the sample above
Kincrc16-xmodem, xxhash, fnv1a

The IEEE CRC-32, the one in ZIP, PNG, gzip and Ethernet. It catches accidental bit flips and nothing else. Anyone can forge a CRC-32 in microseconds, since it's linear.

ts
create("crc32").hash("123456789").digest; // "cbf43926", the standard check value
create("crc32").hash("The quick brown fox jumps over the lazy dog").digest; // "414fa339"

The avalanche panel on the landing makes the linearity visible. Flip one input bit and the CRC changes by a pattern that depends only on where that bit sat, not on the rest of the input. A real hash moves a random half. Printed big-endian, as crc32 tools write it.