SHA-256 is a cryptographic hash function that produces a fixed 256-bit (64 hex characters) output. It is widely used for data integrity verification, digital signatures, and password hashing.

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

32 hex characters

Processed locally

How it works

Each character of your text is fed 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 yourselfin 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 all security applications including TLS certificates, code signing, and HMAC construction.

Output size: 256 bits (64 hex characters)
Standard: FIPS PUB 180-4 (NIST)
Browser API: SubtleCrypto.digest()
Security status: Approved, recommended for all uses

Related operations

For encoding the result as Base64 for transport, try Base64. To generate strong random secrets to hash, use the password generator. For random unique identifiers without a hash collision risk, see the UUID generator.

Frequently asked questions

What is SHA-256?: SHA-256 is a cryptographic hash function that produces a fixed 256-bit (64 hex characters) output. It is widely used for data integrity verification, digital signatures, and password hashing.
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.