CipherTools

Python SHA3-256 Hash Code Example (Online Runner)

Python SHA3-256 hashing code example with runnable snippets to calculate SHA3-256 and verify results online.

Online calculator: use the site SHA-3 text tool.

Calculation method

Use hashlib.sha3_256, encode text to bytes, and call hexdigest() for a 64-character hex digest.

Implementation notes

  • Package: built-in hashlib.
  • Implementation: SHA3-256 is the standardized SHA-3 variant (not the older Keccak variants) and always outputs 32 bytes.
  • Notes: SHA-3 and SHA-2 produce different digests for the same input; pick one and stay consistent across systems.
python
import hashlib


def sha3_256_text(text: str, encoding: str = "utf-8") -> str:
    return hashlib.sha3_256(text.encode(encoding)).hexdigest()

# Example usage
from hashlib import sha3_256

payload = "hello world"
digest = sha3_256(payload.encode("utf-8")).hexdigest()
print(digest)

File hashing example

python
from pathlib import Path
import hashlib
import tempfile


def sha3_256_file(path: Path, chunk_size: int = 1024 * 1024) -> str:
    hasher = hashlib.sha3_256()
    with path.open("rb") as handle:
        for chunk in iter(lambda: handle.read(chunk_size), b""):
            hasher.update(chunk)
    return hasher.hexdigest()


if __name__ == "__main__":
    with tempfile.TemporaryDirectory() as temp_dir:
        sample_path = Path(temp_dir) / "example.bin"
        sample_path.write_bytes(b"example payload\n")
        print(sha3_256_file(sample_path))

If you create files with echo, note it appends a newline by default. Use echo -n or include a \n byte to match this digest.

SHA3-256 file hashes are computed from the file bytes only. The filename or path is not included unless you explicitly hash it as part of the input.

When to use SHA3-256

SHA3-256 is part of the Keccak family and offers strong security properties. Use it when you want SHA-3 compatibility or need diversity beyond SHA-2.

Test vectors

InputExpected SHA3-256
(empty string)a7ffc6f8bf1ed76651c14756a061d662f580ff4de43b49fa82d80a4b80f8434a
abc3a985da74fe225b2045c172d6bd390bd855f086e3e9d525b46bfe24511431532
message digestedcdb2069366e75243860c18c3a11465eca34bce6143d30c8665cefcfd32bffd
abcdefghijklmnopqrstuvwxyz7cab2dc765e21b241dbc1c255ce620b29f527c6d5e7f5f843e56288f0d707521

Complete script (implementation + tests)

python
import hashlib

TEST_VECTORS = {
    "": "a7ffc6f8bf1ed76651c14756a061d662f580ff4de43b49fa82d80a4b80f8434a",
    "abc": "3a985da74fe225b2045c172d6bd390bd855f086e3e9d525b46bfe24511431532",
    "message digest": "edcdb2069366e75243860c18c3a11465eca34bce6143d30c8665cefcfd32bffd",
    "abcdefghijklmnopqrstuvwxyz": "7cab2dc765e21b241dbc1c255ce620b29f527c6d5e7f5f843e56288f0d707521",
}


def sha3_256_hex(data: bytes) -> str:
    return hashlib.sha3_256(data).hexdigest()


def sha3_256_text(text: str, encoding: str = "utf-8") -> str:
    return sha3_256_hex(text.encode(encoding))


def run_tests() -> None:
    for text, expected in TEST_VECTORS.items():
        actual = sha3_256_text(text)
        assert actual == expected, f"SHA3-256 mismatch for {text!r}: {actual} != {expected}"
    print("All SHA3-256 test vectors passed.")


if __name__ == "__main__":
    run_tests()