CRC32 Checksum
Compute a CRC32 checksum in hex and decimal.
How to use
- 1 Choose whether your input is UTF-8 text or hex bytes.
- 2 Type or paste the data into the input box.
- 3 Read the CRC32 result in hex and decimal.
- 4 Toggle uppercase hex if your tooling needs it.
- 5 Copy the checksum.
About CRC32 Checksum
The CRC32 Checksum tool computes the cyclic redundancy check used throughout computing for fast integrity verification.
This is the standard CRC-32 defined by IEEE 802.3 and used by zip and gzip archives, PNG image chunks and Ethernet frames, with the reflected polynomial 0xEDB88320.
Paste any text and the tool returns the checksum as both an 8-digit lowercase hex string and an unsigned decimal integer, updating live as you type.
You can switch the input mode to interpret your input as raw hex bytes instead of UTF-8 text, which is useful when you already have a byte sequence (for example "de ad be ef" or "deadbeef") and want its checksum rather than the checksum of those ASCII characters.
Spaces between bytes are ignored, and the tool flags odd-length or non-hex input rather than guessing.
A toggle switches the hex output between lowercase and uppercase to match whatever your other tooling expects.
CRC32 is a checksum, not a cryptographic hash: it is excellent for catching accidental corruption during transfer or storage, but it is fast to reverse and trivial to collide deliberately, so never use it for security or to verify untrusted downloads.
Everything runs locally in your browser with no upload and no network request, so it works offline and keeps your data private.
FAQ
Which CRC32 variant is this?
The standard IEEE 802.3 CRC-32 with reflected polynomial 0xEDB88320 — the same one used by zip, gzip and PNG. The check value for "123456789" is cbf43926.
Can I use CRC32 to verify a download is genuine?
No. CRC32 only catches accidental corruption. It is not collision-resistant, so use SHA-256 or another cryptographic hash for security or authenticity checks.
Does it handle binary data?
Yes, indirectly. Switch to hex-bytes mode and paste the bytes as hex; the checksum is computed over those raw bytes rather than their text representation.