StringMash.com

SHA-256 generator

The SHA-256 hash of your text, computed on your device.

3 characters
Updates as you type

Show the steps
  1. SHA-256 of 3 bytes of UTF-8: 256 bits, written as 64 hex digits. The same input always gives the same hash, and any change gives a completely different one.
  2. SHA-256 is a current, secure general-purpose hash.
  3. Hashing is one-way: there is no key, and the input can't be worked back out from the hash. For passwords, use a slow, salted function such as bcrypt, scrypt or Argon2 rather than any of these.

Using the generator

Type or paste text and the SHA-256 hash appears, 64 hex digits. The text is hashed as UTF-8, which is what nearly every other tool and library does, so the result matches theirs. Algorithm switches to MD5, SHA-1, SHA-384 or SHA-512, and Letters gives capitals if you need them.

Hashing runs in your browser through the Web Crypto API. Nothing you type is sent anywhere.

What SHA-256 is for

SHA-256 turns any input into a 256-bit fingerprint. The same input always gives the same hash, a one-letter change gives a completely different one, and there's no known way to find two inputs with the same hash. That makes it right for checking a download, naming content, and signing. It isn't right for storing passwords on its own: see hashing vs encryption.

Questions

Can a SHA-256 hash be reversed?

No. It's one-way. A short or common input can be guessed and checked, but the hash itself gives nothing back.

Why doesn't my hash match another tool's?

Usually a hidden difference in the input: a trailing newline, a space, or a different text encoding. This page hashes exactly what's in the box as UTF-8.

What's the SHA-256 of an empty string?

e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855.

Sources

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