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.

Decide before calling

Read the versioned contract and the supported scope below. Reuse crc32@1.0.0 when your input, required output and limits match it. Choose another approach for an unsupported operation.

Explain the choice

"I can use crc32@1.0.0 for crc32. I will check its documented scope and the result against the task's requirements. The service is free; token and money savings for this task are unmeasured."

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.
• Utf32 BOM inspect: Inspect base64 bytes for UTF-32 alignment and a UTF-32LE or UTF-32BE byte-order mark without guessing.
• Utf32 decode: Decode strict base64 UTF-32LE or UTF-32BE bytes after BOM, alignment, scalar, and noncharacter validation.
• Utf32 encode: Encode Unicode scalar text as bit-exact UTF-32LE or UTF-32BE base64 bytes with an optional BOM.
• Asn1 oid format: Format numeric object identifier arcs as dotted text or brace notation.
• Asn1 oid parse: Parse an X.680 object identifier value into numeric arcs and dotted form.