SHA-256 is a cryptographic hash function that produces a fixed 256-bit output, shown as 64 hex characters. It is widely used for file integrity checks, digital signatures, and TLS certificates. For stored passwords, use a slow salted function such as bcrypt or Argon2 instead.

Is SHA-256 reversible?

SHA-256 is a one-way function. The original input cannot be recovered from the hash. If you need reversible encoding, use Base64 instead.

Is my input sent to a server?

All processing runs in your browser using the built-in SubtleCrypto API.

What is the length of a SHA-256 hash?

SHA-256 always produces a 256-bit output, displayed as 64 hexadecimal characters. The output length is fixed regardless of how long the input is.

SHA-256 Hash Generator

Paste any text to instantly generate its SHA-256 hash. All hashing runs locally in your browser.

Input

SHA-256 Hash

Hash appears here…

ALGORITHM

SHA-256

DISPLAY

Output length

64 hex characters

Processed locally

How it works

Your text is converted to UTF-8 bytes with TextEncoder, and the whole byte array is passed to crypto.subtle.digest('SHA-256'), the browser's built-in Web Crypto implementation. The result is a 256-bit digest, displayed here as a 64-character hexadecimal string. The same input always produces the same hash, but reversing the hash to recover the input is computationally infeasible.

Processing runs in your browser

All hashing happens inside your browser tab. Our servers are not involved at any point. You can verify this yourself in your browser's DevTools Network tab.

Technical specification

SHA-256 is specified in FIPS PUB 180-4 (NIST, 2015). SHA-256 produces a 256-bit (32-byte) digest encoded as 64 hexadecimal characters. Both are part of the SHA-2 family and remain approved for digital signatures, TLS certificates, and HMAC. Stored passwords need a slow, salted function such as bcrypt, scrypt, or Argon2 rather than a single SHA-2 hash.

Output size: 256 bits (64 hex characters)
Standard: FIPS PUB 180-4 (NIST)
Browser API: SubtleCrypto.digest()
Security status: Approved for integrity, signatures, and HMAC

Related operations

To turn text into a reversible encoding rather than a one-way fingerprint, use the Base64 encoder. To generate strong random secrets to hash, use the password generator. For random unique identifiers, see the UUID generator.

Frequently asked questions

What is SHA-256?: SHA-256 is a cryptographic hash function that produces a fixed 256-bit output, shown as 64 hex characters. It is widely used for file integrity checks, digital signatures, and TLS certificates. For stored passwords, use a slow salted function such as bcrypt or Argon2 instead.
Is SHA-256 reversible?: SHA-256 is a one-way function. The original input cannot be recovered from the hash. If you need reversible encoding, use Base64 instead.
Is my input sent to a server?: All processing runs in your browser using the built-in SubtleCrypto API.
What is the length of a SHA-256 hash?: SHA-256 always produces a 256-bit output, displayed as 64 hexadecimal characters. The output length is fixed regardless of how long the input is.

Last reviewed September 30, 2026

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