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About this tool
Generate a SHA-256 hash of any text, computed securely in your browser.
The SHA-256 Hash Generator computes the SHA-256 digest of any text you paste — a 256-bit value shown as 64 lowercase hexadecimal characters — using the browser's native Web Crypto engine. Your text is encoded as UTF-8 before hashing, so the result matches what sha256sum, OpenSSL, Python's hashlib or a Node crypto call would return for the same bytes. It is built for developers verifying a checksum, an API signature or a stored digest without pasting the value into someone else's server.
Open SHA-256 Hash Generator on AltFTool — it loads instantly in your browser.
Type or paste your text into the Input box — it is UTF-8 encoded before hashing, and 'Load sample' fills in the example 'hello world'.
The Result box updates live as you edit, with no convert button: the digest comes from the browser's own crypto.subtle.digest('SHA-256') call.
Press Copy next to Result to copy the 64-character lowercase hex hash, or Clear above the Input box to start over.
The digest comes from the browser's own audited crypto implementation, so it is both fast on large inputs and free of reimplementation bugs.
Because the hashing is local, you can safely digest a token, a secret or an unreleased payload that must not touch a third-party endpoint.
The hash updates as you edit and copies whole, which is how you spot that a stray newline is what broke your comparison.
b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9. SHA-256 output is always 256 bits — 64 hex characters — regardless of input size; the empty string hashes to e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855.
Usually the bytes differ rather than the algorithm. A trailing newline, Windows CRLF line endings instead of LF, or a different text encoding changes every character of the digest. Also check you are comparing against SHA-256 and not SHA-1 or MD5 — the lengths give it away at 64, 40 and 32 hex characters respectively.
Yes, for integrity and signatures: there is no known practical collision or preimage attack against it, which is why it underpins TLS certificates and Bitcoin. It is still the wrong choice for storing passwords, because it is designed to be fast — use bcrypt, scrypt or Argon2 with a per-user salt for that.
No. It is a one-way digest, not encryption, and the original input is not recoverable from the 64 characters. Short, guessable inputs can still be identified by hashing candidates and comparing, so a hash alone is not a way to hide a value.