Is my text sent to a server?

No. The hash is computed locally using your browser's built-in Web Crypto API (crypto.subtle.digest). Your text never leaves your device and nothing is uploaded.

Yes. SHA-256 is part of the SHA-2 family and is widely considered secure. It is used in TLS certificates, Bitcoin, file integrity verification, and digital signatures. For password storage, use a dedicated password hash such as bcrypt or Argon2 instead of a raw SHA-256.

How long is a SHA-256 hash?

A SHA-256 hash is 256 bits, shown as 64 hexadecimal characters. The length is always 64 hex characters regardless of how long or short the input is.

Is SHA-256 reversible?

No. SHA-256 is a one-way function — you cannot recover the input from the hash. The only way to "reverse" it is to guess inputs and hash them until one matches, which is why it is used for integrity checks and fingerprints.

Will the same text always give the same hash?

Yes. SHA-256 is deterministic: identical input always yields identical output. Even a one-character change produces a completely different hash, which is what makes it useful for detecting tampering.

What is SHA-256 used for?

It verifies file integrity (checksums), signs TLS certificates, secures the Bitcoin and other blockchains, and acts as a building block in HMAC and digital signatures. It confirms that data has not changed.

SHA-256 Hash Generator

SHA-256 hash generator

This tool turns any text into its SHA-256 digest — a fixed 256-bit fingerprint shown as 64 hexadecimal characters. It’s used to verify that a file or message hasn’t changed, to compare values without storing the original, and as a building block in TLS, blockchains, and digital signatures. The hash updates as you type and never leaves your browser.

How it works

The input text is encoded to UTF-8 bytes with TextEncoder, then hashed by the browser’s native Web Crypto API via crypto.subtle.digest("SHA-256", data). The resulting ArrayBuffer is converted to a lowercase hex string. SHA-256 is deterministic (same input, same output) and one-way (you cannot derive the input from the hash), and a single changed character flips roughly half the output bits.

Example

Input	SHA-256 (first 16 of 64 hex chars)
`hello`	`2cf24dba5fb0a30e…`
`Hello`	`185f8db32271fe25…`
(empty string)	`e3b0c44298fc1c14…`

Note how hello and Hello produce entirely different digests — that sensitivity to change is the point.

A note on passwords: SHA-256 is too fast to be a safe password store on its own. For passwords use a purpose-built, deliberately slow hash like bcrypt or Argon2. Hashing here runs entirely in your browser, so it is safe to use with sensitive strings — nothing is uploaded.