Generate SHA-256 hashes from any text using the browser's native Web Crypto API. Industry-standard 256-bit cryptographic hashes for checksums, digital signatures, and data integrity. 100% private.
Type or paste any text into the input box. The SHA-256 hash is computed asynchronously using your browser's native Web Crypto API — the same cryptographic engine used for HTTPS. Large inputs are handled efficiently.
The 64-character hexadecimal SHA-256 hash appears instantly. Toggle between hex (lowercase/uppercase) and Base64 representations using the format buttons. The hash updates automatically as you edit the input.
Click Copy to copy the hash. Use the Verify tab to paste a known SHA-256 hash and confirm whether your input matches — useful for verifying software downloads, API signatures, and file integrity.
SHA-256 (Secure Hash Algorithm 256-bit) is a cryptographic hash function from the SHA-2 family, standardised by NIST. It produces a fixed 256-bit (64 hexadecimal character) hash from any input. SHA-256 is used in TLS/SSL certificates, Bitcoin and most blockchains, code signing, git commit hashes, HMAC authentication, and API signature verification.
SHA-256 alone is not recommended for password hashing because it is too fast — attackers can test billions of SHA-256 hashes per second using GPUs. Password hashing requires slow, memory-hard algorithms designed to make brute force impractical: use bcrypt, scrypt, or Argon2 for passwords. SHA-256 is excellent for data integrity, checksums, and HMAC, but not for raw password storage.
MD5 produces a 128-bit hash (32 hex chars) and is considered cryptographically broken — practical collision attacks exist. SHA-256 produces a 256-bit hash (64 hex chars) and is currently considered secure with no known practical collisions. SHA-256 is significantly more resistant to brute force due to its larger output space (2²⁵⁶ possible hashes vs 2¹²⁸ for MD5). SHA-256 is slower to compute, which is a security advantage.
The Web Crypto API (window.crypto.subtle) is a browser-native cryptographic library built into all modern browsers (Chrome, Firefox, Safari, Edge). It provides hardware-accelerated implementations of standard algorithms including SHA-256. Using the Web Crypto API means this tool requires no external library, is as fast as native code, and has been audited as part of the browser.
SHA-256 is a one-way function — it is computationally infeasible to reverse a SHA-256 hash to recover the original input (for any input that is not guessable by brute force). The output space has 2²⁵⁶ possible values — more than the estimated number of atoms in the observable universe — making exhaustive search impossible with any foreseeable technology.
HMAC (Hash-based Message Authentication Code) SHA-256 is SHA-256 combined with a secret key to create a keyed hash. Unlike plain SHA-256, HMAC-SHA256 verifies both data integrity and authenticity — an attacker cannot forge a valid HMAC without knowing the secret key. HMAC-SHA256 is used for API authentication (AWS Signature V4, JWT HS256), webhook verification, and secure cookies.
