CRC32 & Adler-32 Checksum

Compute the non-cryptographic CRC-32 (IEEE 802.3, used by ZIP / PNG / Ethernet) and Adler-32 (zlib) checksums of text or files — entirely in your browser. Useful for integrity checks where a cryptographic hash is overkill.

Input text

…or a file

Click to choose, or drag & drop a file here

Uppercase hex

Expected checksum (optional)

CRC-32 uses the standard reflected polynomial 0xEDB88320 (init and final XOR with 0xFFFFFFFF). Adler-32 accumulates mod 65521. Everything is computed locally — nothing is uploaded.