CRC32, CRC16 & CRC8 Checksum Calculator
Cyclic redundancy checks for data integrity.
Free · no sign-up · runs locally·
About this tool
CRCs are fast error-detection codes, not cryptographic hashes: they catch transmission and storage corruption but offer no protection against deliberate tampering. CRC32 (as used in ZIP, PNG, and Ethernet), CRC16-CCITT, and CRC8 are computed here bit-for-bit in your browser.
Like everything on encrypt.tools, this runs entirely in your browser — nothing you enter is transmitted or stored.
Do the same in a terminal
Reproduce or cross-check this tool with standard command-line utilities. For deterministic operations like hashing and encoding, the output matches exactly.
$ python3 -c 'import zlib; print(format(zlib.crc32(b"hello"), "08x"))'
3610a686Frequently asked questions about CRC Checksum
Is a CRC a secure hash?+
No — CRCs detect accidental corruption (transmission errors, bad sectors) but offer no protection against deliberate tampering. They're error-detection codes, not cryptographic hashes.
Where is CRC32 used?+
In ZIP archives, PNG images, Ethernet frames, and many storage and networking protocols to catch bit errors.
Why do the values differ from another tool?+
There are many CRC variants differing in polynomial, initial value, and bit reflection. This tool uses CRC32 (IEEE 802.3), CRC16-CCITT, and CRC8 (poly 0x07).