Hash generator

What this hash generator does

Type or paste text and get its SHA-1, SHA-256, SHA-384 or SHA-512 digest as lowercase hexadecimal, recomputed on every keystroke. The tool encodes the text as UTF-8 and hands the bytes to crypto.subtle.digest, the same implementation browsers use for TLS and WebAuthn — so the result is exactly what sha256sum would print for the same bytes. Nothing is uploaded; the digest is computed locally.

How to use it

1. Paste the text into the Text box. Everything you type counts, including trailing spaces and line breaks.
2. Pick the Algorithm (SHA-256 is preselected).
3. Read the digest in the panel below and click Copy.

To hash several variants, just edit the text — the digest updates live, so you can watch how a single changed character produces a completely different output (the avalanche effect).

Algorithm reference

Algorithm	Digest size	Hex length	Status (2025)	Typical use
MD5	128 bit	32	Broken — collisions in seconds	Legacy checksums only; not available here
SHA-1	160 bit	40	Broken for collisions (SHAttered, 2017)	Git object IDs, legacy systems; avoid for security
SHA-256	256 bit	64	Secure	TLS certificates, Bitcoin, content hashes, HMAC keys, JWT HS256/RS256
SHA-384	384 bit	96	Secure	Subresource Integrity (sha384-…), ECDSA P-384
SHA-512	512 bit	128	Secure	Long-term integrity, faster than SHA-256 on 64-bit CPUs

SHA-256, 384 and 512 are the SHA-2 family; SHA-384 is SHA-512 truncated with different initial values. Browsers can verify integrity="sha256-…", sha384-… and sha512-… attributes, but the value there is Base64 of the raw bytes, not hex — pipe the digest through the Base64 converter after converting hex to bytes, or use openssl dgst -sha384 -binary file.js | openssl base64 -A.

Known answers to sanity-check against

Input	Algorithm	Digest
(empty string)	SHA-256	e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
abc	SHA-256	ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad
abc	SHA-1	a9993e364706816aba3e25717850c26c9cd0d89d

Clear the text box and you will see the famous e3b0c442… empty-string digest. If a build or verification step shows that value, it hashed nothing — usually a missing file or an empty variable.

What hashes are — and are not — good for

A cryptographic hash is a one-way, fixed-size fingerprint: the same input always gives the same digest, a tiny change gives an unrelated one, and finding an input for a given digest is infeasible. That makes it right for:

• Integrity checks — compare the digest of a download with the one the publisher lists.
• Content addressing and cache keys — name a file by its SHA-256 and you get deduplication for free.
• Commit signatures and Merkle trees — Git, package lockfiles, blockchains.
• HMAC — hashing with a secret key for message authentication (JWT HS256 is HMAC-SHA256).

It is not encryption (there is no key and no way back), and it is not a password store. Hashing is designed to be fast, which is the opposite of what password storage needs; use Argon2id, bcrypt or scrypt with a per-user salt and a cost factor tuned to roughly 100 ms. Likewise, hashing an email address or phone number does not anonymize it — the input space is small enough to enumerate.

Hashing in your own code

The browser call is the same one this tool makes:

async function sha256Hex(text: string): Promise<string> {
  const bytes = new TextEncoder().encode(text);
  const digest = await crypto.subtle.digest('SHA-256', bytes);
  return [...new Uint8Array(digest)].map((b) => b.toString(16).padStart(2, '0')).join('');
}

crypto.subtle is only available in secure contexts (HTTPS or localhost). In Node, createHash('sha256').update(text).digest('hex') from node:crypto is equivalent and also offers MD5.

Related tools and snippets

• Base64 encoder / decoder — Subresource Integrity and many APIs want digests as Base64 rather than hex.
• UUID generator — when you need a random identifier rather than a fingerprint of existing data.
• JWT decoder — see where HMAC-SHA256 is used in practice.
• Text diff — two strings hash differently and you cannot see why? Diff them to find the invisible character.
• Number base converter — read a hex digest’s bytes as decimal or binary.