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SHA-256 Hash Generator — Compute SHA-256 Hashes

The industry-standard hash for verifying file downloads and detecting tampering — a unique 64-character fingerprint.

Result

Hash chaining feeds each digest back in as the next input: H(H(…H(input))). Bitcoin uses double SHA-256 (2). This is not a password KDF — use PBKDF2, bcrypt, or scrypt for passwords.

What is SHA-256 Hash?

SHA-256 is a cryptographic hash function in the SHA-2 family, producing a fixed 256-bit (64-character hex) output from any input. It's the workhorse of modern internet security. For a broader SHA comparison, start with our Hash Generator hub.

Deterministic — the same input always produces the same hash.
Avalanche effect — changing a single bit of input flips roughly half the output bits.
Preimage resistant — you can't reverse the hash to recover the original input.
Used everywhere — TLS certificates, Bitcoin mining, file integrity checks, and digital signatures all rely on SHA-256.

Zero-Server Tool Data Guarantee

All hashing happens locally in your browser. Your input is never sent to any server.

How to Use

01

Enter Your Text

Type or paste the text you want to hash into the input area.

02

View the Hash

The SHA-256 hash is computed instantly as you type. It is displayed as a 64-character hex string.

03

Verify a Checksum

Switch to the Verify tab and paste a published checksum — sha256sum-style output works too — to confirm it matches the hash of your input.

04

Copy the Result

Use the copy button to save the hash to your clipboard.

Common Use Cases

File Integrity Verification

Generate a checksum before and after file transfer to confirm nothing was modified in transit.

Password Storage

Hash passwords before storing them. Always combine with a unique per-user salt and a slow KDF like bcrypt.

Data Deduplication

Hash content to detect duplicate files or records without comparing them byte-by-byte.

Digital Signatures

Hash the document first, then sign the hash — this is faster and more secure than signing raw data.

Implementation Examples

JavaScriptBrowser (Web Crypto API)
async function sha256(message) {
    const msgBuffer = new TextEncoder().encode(message);
    const hashBuffer = await crypto.subtle.digest('SHA-256', msgBuffer);
    const hashArray = Array.from(new Uint8Array(hashBuffer));
    return hashArray.map(b => b.toString(16).padStart(2, '0')).join('');
}


const hash = await sha256('hello world');
// "b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9"

SHA-256 vs SHA-512 vs MD5

PropertySHA-256SHA-512MD5
Output size256-bit (64 hex)512-bit (128 hex)128-bit (32 hex)
Security level128-bit (unbroken)256-bit (unbroken)Broken (collisions found)
Speed (64-bit CPU)FastFaster on 64-bitFastest
Use for passwords?No (too fast)No (too fast)Never
Current recommendationRecommendedRecommendedAvoid for security
NIST approved?YesYesDeprecated

Which SHA-2 Size?

SHA-2 sizeOutputCollision resistanceBest for
SHA-22456 hex112-bitLegacy compatibility, compact checksums on constrained systems
SHA-256You're here64 hex128-bitGeneral purpose — file integrity, TLS, signatures, blockchain
SHA-512128 hex256-bitMaximum security margin, high-assurance certificates
SHA-512/25664 hex128-bitSHA-256's size with SHA-512's speed — length-extension resistant

All SHA-2 sizes use the Merkle-Damgård construction from NIST FIPS 180-4. SHA-224 truncates SHA-256's output, and SHA-512/256 truncates SHA-512's — which is what gives it length-extension resistance.

Production Best Practices & Security

Don't use SHA-256 alone for passwords — it's too fast; use bcrypt, scrypt, or PBKDF2 instead. Why:SHA-256 is designed to be extremely fast. An attacker can compute billions of SHA-256 hashes per second on modern hardware, making brute-force attacks trivial.
Use a salt for uniqueness — without a salt, identical inputs produce identical hashes, enabling rainbow table attacks. Why:Salting ensures that even if two users have the same password, their hashes will be different. This prevents attackers from using pre-computed tables (rainbow tables) to crack millions of hashes at once.
Verify integrity end-to-end — compute the hash at the source and verify it at the destination to detect tampering. Why:If a file or message is altered in transit, the hash will change completely. Comparing the original hash with the received hash is the most reliable way to ensure data integrity.
Prefer SHA-256 over SHA-1 — SHA-1 has known collision vulnerabilities; SHA-256 remains unbroken. Why:Cryptographic researchers have demonstrated that SHA-1 is no longer secure because two different inputs can produce the same hash (a collision). SHA-256 has a much larger output space and no known practical attacks.
Use HMAC for authenticated hashing — if you need both integrity and authenticity, use HMAC-SHA-256 with a secret key. Why:A standard hash only proves the data wasn't changed by accident. An HMAC uses a secret key to prove that the hash was generated by someone who knows that key, preventing "length extension" attacks.
Never store plaintext passwords — for credentials, store a slow-KDF hash (bcrypt, scrypt, Argon2, PBKDF2) with a unique salt, never the password itself or a plain SHA-256 of it. Why:A plain SHA-256 of a password can be brute-forced billions of times per second, and unsalted hashes let attackers use precomputed rainbow tables. The hash is only useful for verification, never for recovering the secret.

Frequently Asked Questions

On Linux or macOS, run: sha256sum filename. On macOS (alternative): shasum -a 256 filename. On Windows PowerShell, run: Get-FileHash -Algorithm SHA256 filename, or on Command Prompt: certutil -hashfile filename SHA256.

Compare the output character-for-character with the checksum published by the software vendor. A mismatch indicates the file was corrupted during download or tampered with.

For text input, paste into BetterPass's SHA-256 tool. For binary files, always use your OS's built-in tool to avoid encoding issues.