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SHA-256 Hash Generator

Runs in browser

Generate SHA-256 hashes from text instantly. WebCrypto hardware-accelerated, real-time output. Used in Bitcoin, TLS, and digital signatures. Zero uploads.

Last updated 02 Apr 2026

Type or paste any text and get its SHA-256 hash in real time. Hardware-accelerated via the browser's WebCrypto API, supports uppercase output, and runs entirely client-side — nothing is uploaded.

Looking for SHA-256 Decrypt / Lookup?

SHA-256 is a 256-bit (64 hex character) hash from the SHA-2 family, widely used in TLS certificates, code signing, and Bitcoin. While SHA-256 is collision-resistant, unsalted SHA-256 passwords can be looked up in rainbow tables. For password storage, use bcrypt. Lookup uses rainbow table databases — salted hashes cannot be reversed.
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How to use

  1. 1

    Open the Generate tab

    Ensure the 'Generate' tab is active — it is the default on this page.

  2. 2

    Type or paste your text

    Enter any text in the input field. The SHA-256 hash updates in real time as you type, powered by the browser's WebCrypto API.

  3. 3

    Toggle uppercase if needed

    Check 'Uppercase' in the options bar to output the hash in uppercase letters — useful for hex comparison with some systems.

  4. 4

    Copy the result

    Click the Copy button next to the output to copy the 64-character SHA-256 hash to your clipboard.

  5. 5

    Verify or reverse lookup

    Switch to the Lookup tab to check whether a known SHA-256 hash has a match in rainbow table databases.

Frequently asked questions

What is SHA-256?
SHA-256 (Secure Hash Algorithm 256-bit) is a cryptographic hash function from the SHA-2 family, standardized by NIST. It produces a 256-bit (64 hex character) output and is the most widely used hash algorithm in the world, found in TLS, Bitcoin, code signing, and file integrity verification.
Is SHA-256 safe for password storage?
No. Unsalted SHA-256 is vulnerable to rainbow table attacks — large precomputed databases of hash→plaintext pairs. Modern GPUs can compute billions of SHA-256 hashes per second. For password storage, use a purpose-built key derivation function like bcrypt, Argon2id, or scrypt.
Does this tool upload my text?
No. SHA-256 hashing uses the browser's WebCrypto API (crypto.subtle.digest), which runs entirely client-side. Nothing is sent to any server.
Are inputs sent to a server?
No. The Generator tab is strictly local — there are zero network requests. The Lookup tab (reverse lookup) does query external rainbow table APIs, but the Generator itself has no outbound traffic.
What is WebCrypto and why does this tool use it?
WebCrypto is the W3C Web Cryptography API built into all modern browsers. It delegates cryptographic operations to the operating system's native crypto library, which is often hardware-accelerated (via Intel SHA Extensions or ARM SHA2 instructions). This makes SHA-256 faster in the browser than many pure-JavaScript implementations.
How does SHA-256 compare to MD5?
SHA-256 produces a 64-character (256-bit) output vs MD5's 32-character (128-bit) output. SHA-256 has no known practical collision attacks, while MD5 is considered cryptographically broken. For any new system, prefer SHA-256.
What is SHA-256 used for in practice?
SHA-256 appears in TLS certificate fingerprints, Git commit hashes, Bitcoin mining (double-SHA-256), JWT HS256 signatures, HMAC-SHA256 API authentication, npm package integrity checks (package-lock.json), and file integrity verification for software downloads.
Can SHA-256 hashes be reversed?
Not mathematically — SHA-256 is a one-way function. However, very common strings may appear in rainbow table databases. The SHA-256 Decrypt tool can check these databases, though match rates are much lower than for MD5.
Why does the same text always produce the same SHA-256 hash?
SHA-256 is a deterministic function — identical inputs always produce identical outputs. This property makes it useful for integrity verification: if a file's SHA-256 matches the expected value, the file is unmodified.

Generate SHA-256 hashes from any text string with hardware acceleration

in your browser.

**SHA-256** (Secure Hash Algorithm 256-bit) is part of the SHA-2 family,

designed by the NSA and standardized by NIST. It produces a 256-bit

(64 hex character) hash and is used everywhere security matters:

- **TLS/SSL certificates** — server identity verification in HTTPS

- **Bitcoin proof-of-work** — the mining algorithm for the Bitcoin network

- **Code signing** — Authenticode, Apple notarization, and APK signing

- **File integrity** — verifying ISO images, package managers (npm, pip, apt)

- **Digital signatures** — ECDSA and RSA signatures in JWT and SSH

- **HMAC-SHA256** — API authentication tokens and webhook verification

**This tool uses WebCrypto** (`crypto.subtle.digest`), the browser's native

cryptography API. SHA-256 computation is often hardware-accelerated via

Intel SHA extensions, running faster than most JavaScript implementations.

**Not suitable for password storage** — unsalted SHA-256 is vulnerable to

rainbow table attacks. Use bcrypt, Argon2, or scrypt for passwords.

All processing is client-side. Your text never leaves your device.

Related tools

SHA-256 Decrypt — Hash Lookup

Look up SHA-256 hashes against rainbow table databases. Not true decryption — SHA-256 is one-way. Works only for common, previously indexed strings.

MD5 Hash Generator

Generate MD5 hashes from text in real time. Instant output, uppercase toggle, 100% browser-based. Not for passwords — use bcrypt instead.

Bcrypt Hash Generator

Generate bcrypt hashes with configurable cost factor (4–31). Auto-salted, rainbow-table resistant, fully browser-based. Recommended for secure password storage.

Hash Generator

Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from text or files instantly in your browser.

AES Encrypt

Encrypt text with AES-256-GCM, AES-CBC, AES-CTR, or AES-ECB in your browser. PBKDF2 key derivation, random IV, zero uploads.

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