SHA-256 Hash Generator
Hash any text to a 64-character SHA-256 digest, live as you type.
How SHA-256 behaves
SHA-256 takes input of any length and returns exactly 256 bits. The mapping is deterministic — the same input always gives the same digest — and it is designed so that changing a single bit of input changes roughly half the output bits, with no way to predict which. That avalanche property is what makes a digest useful as a fingerprint.
Try it above: edit one character of the input and watch the entire hash change. That is not a quirk of the display; every one of the 64 hex digits is recomputed, and there is no visible relationship between the old digest and the new one.
The property that matters for security is collision resistance — the difficulty of finding two different inputs with the same digest. SHA-1 fell to exactly this attack in 2017 and should no longer be used. SHA-256 has no known practical collision attack and remains the recommended default.
Frequently asked questions
What is SHA-256 used for?
It is the workhorse hash of modern computing: file integrity checks, digital signatures, TLS certificates, Git object identifiers, and Bitcoin's proof of work all rely on it. Any time you need a short fixed-length fingerprint of arbitrary data, SHA-256 is the usual answer.
Can a SHA-256 hash be reversed?
No. Hashing is one-way by design — the digest discards information, so there is no decrypt operation. What attackers do instead is guess: hash enormous lists of likely inputs and look for a match. That is why hashing a password with plain SHA-256 is not enough.
Why is the output always 64 characters?
SHA-256 always produces 256 bits regardless of input size, and 256 bits written as hexadecimal is 64 characters. A single letter and a gigabyte file both yield a 64-character digest.
Should I use SHA-256 to store passwords?
No. It is far too fast, which helps an attacker brute-force billions of candidates per second. Use a deliberately slow, salted algorithm built for the job — bcrypt, scrypt, or Argon2.
Is my input sent anywhere?
No. The digest is computed locally by the browser's WebCrypto API. Your text never leaves the page.