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SHA-256 Hash Generator

256-bit SHA-256 digest of the input bytes. This is the default integrity hash on CZNull.

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Input
Output

How to generate a SHA-256 hash

  1. Paste the text, hex, or Base64 you want to hash.
  2. Set Input encoding (UTF-8 for normal text).
  3. Choose hex or Base64 output. Turn on HMAC and enter a key if you need a keyed digest.
  4. Compare the result to a published checksum using an exact string match.

SHA-256

SHA-2 family cryptographic hash function

Digest size256 bits (64 hex characters)
Block size512 bits
StandardFIPS 180-4 / SHA-2
EngineWeb Crypto subtle.digest("SHA-256"), or HMAC-SHA-256

What SHA-256 is

SHA-256 is a 256-bit member of SHA-2. People use it for file integrity, Git objects, and many certificate fingerprints. Public collision attacks are not practical today.

Still matching a legacy checksum? See MD5 and SHA-1, or browse all hash tools.

How this page hashes

Input encoding turns what you paste into bytes. Those bytes go to the browser Web Crypto API as SHA-256 or HMAC-SHA-256. If Web Crypto is missing, the workbench reports an error instead of a guessed digest.

When to use SHA-256

Use SHA-256 for checksums and content addressing. It is not a password storage function by itself. Pair a password with a slow KDF such as Argon2 or bcrypt in your own stack. Hashing is not encryption. Anyone can hash the same input and compare.

HMAC-SHA-256

Turn on HMAC when you need a keyed digest. The page hashes the message with your key using HMAC-SHA-256. Set key encoding to match how the other system stores the key. Empty input still produces a defined digest of the empty byte string.

SHA-256 questions

Is SHA-256 computed on CZNull's servers?
No. The browser Web Crypto API hashes the bytes on your device.
How is this different from MD5?
SHA-256 is 256 bits and remains suitable for integrity. MD5 is 128 bits and collision-broken.
Does empty input produce a hash?
Yes. The SHA-256 of an empty byte string is a defined value, not an error.
What is HMAC on this page?
HMAC-SHA-256 combines a key with the message. Turn on HMAC, set the key encoding, and enter the key. The output is still 256 bits.
Can I hash a file?
This page hashes what you paste (text, hex, or Base64). File hashing is not on this page yet.