CRC32 Calculator
Compute the CRC32 checksum of any text. Shown as hex, unsigned decimal, and signed decimal.
What is CRC32?
CRC32 (Cyclic Redundancy Check, 32-bit) is a checksum algorithm based on polynomial division over GF(2). The standard IEEE 802.3 polynomial (0xEDB88320 in reversed form) is used throughout the computing stack — ZIP archives, PNG images, Ethernet frames, gzip, and many storage and network protocols.
CRC32 vs cryptographic hashes
CRC32 is designed to detect random errors like flipped bits during transmission or storage. It is notcryptographic: it's trivial to construct two messages with the same CRC32, and CRC32 has no key. Never use CRC32 as a signature, password hash, or anywhere an attacker might tamper with data. For those uses pick SHA-256 or HMAC.
Common uses
CRC32 shines as a fast, cheap integrity check: file checksums in ZIP and gzip, frame integrity in Ethernet, identifiers in PNG chunks, and cache keys where collisions are inconvenient but not dangerous. The same checksum is often displayed as hex, signed, or unsigned decimal depending on the tool — they're the same 32 bits, just formatted differently.