CRC-32

crc32 · version 1.0.0 · Encoding & checksums · free, no key needed

CRC-32 of UTF-8 bytes (ISO 3309 / ZIP / PNG polynomial). Integrity check only; no security claim.

Use when you need to: crc32 · crc-32 · zip crc32.

Supported

• crc32
• crc-32
• zip crc32

Not supported

• crc32c
• hmac
• sha
• cryptographic hash

Behavior

• UTF-8 encode text. CRC-32 with polynomial 0xEDB88320, init 0xFFFFFFFF, final XOR 0xFFFFFFFF.
• hex is 8 lowercase hex digits, zero-padded. value is the unsigned 32-bit integer as a JSON number (0..4294967295).
• This is an integrity checksum, not a cryptographic hash, MAC, or password hash.

Input

• text (string, required): max length 256000

Output

• hex (string, required): min length 8; max length 8
• value (integer, required): min 0; max 4294967295

Limits

• max input bytes: 256000

Example

Request input:

{
  "text": ""
}

Response:

{
  "result": {
    "hex": "00000000",
    "value": 0
  }
}

How to call it

MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "crc32",
  "version": "1.0.0",
  "input": {
    "text": ""
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/crc32/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"text":""}'

The machine-readable contract is at /v1/tools/crc32/versions/1.0.0.

CLI

node cli.mjs run crc32 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• Adler-32: Adler-32 of UTF-8 bytes (RFC 1950). Integrity check only; no security claim.
• Base64 UTF-8: Decode standard Base64 to UTF-8 text. Transformation only; no security claim.
• Hex bytes concat: Concatenate a bounded ordered list of lowercase hex byte strings into one hex string.
• Hex bytes slice: Slice a lowercase hex byte string by explicit byte-index bounds, half-open like Array.slice.
• Hex bytes xor: Byte-wise XOR of two equal-length lowercase hex byte strings. Transformation only; no cryptographic security claim.
• UTF-8 Base64: Encode a Unicode string as standard Base64 of its UTF-8 bytes. Transformation only; no security claim.