Free SHA-256 Hash Generator Online
Generate SHA-256 hashes instantly in your browser — no data sent to any server.
Input
Output
What Is SHA-256 Hashing?
You need to sign an API request, verify a file wasn't corrupted in transit, or store a password hash securely. SHA-256 handles all of that. It's part of the NIST FIPS 180-4 Secure Hash Standard — the same standard used by TLS certificates, Bitcoin mining, and most modern authentication systems. SHA-256 produces a 256-bit (64-hex-character) output with no known practical collisions. The MDN SubtleCrypto.digest() docs show how browsers implement it natively. For production systems, OWASP's Cryptographic Storage Cheat Sheet recommends SHA-256 (or stronger) for all new systems. This tool runs entirely in your browser using the Web Crypto API — your input never reaches a server.
SHA-256 is considered cryptographically secure and is used in TLS/SSL certificates, Bitcoin mining, digital signatures, and file integrity verification. The algorithm is specified in RFC 6234. This tool computes the SHA-256 hash of your entire input text using the Web Crypto API directly in your browser.
How to Use This Tool
Enter Your Text
Type or paste text into the left editor. You can also click Sample to load example text, or Upload a text file.
View the SHA-256 Hash
The right panel displays the SHA-256 hash of your input automatically. The hash updates in real time as you type.
Copy or Download
Click Copy to copy the hash to your clipboard, or Download to save it as a text file.
Hash Examples
Here is an example of SHA-256 hashing:
Input Text
SHA-256 Hash Output
Frequently Asked Questions
Is SHA-256 secure?
Yes. SHA-256 has no known practical collision or preimage attacks. It is the current standard for TLS certificates, code signing, and password hashing (via bcrypt and PBKDF2 which use SHA-256 internally). See NIST FIPS 180-4 for the formal specification.
How is SHA-256 used in Bitcoin?
Bitcoin uses SHA-256 (double-hashed) for its proof-of-work algorithm. Miners must find a nonce that makes the block header hash below a target threshold. This is computationally expensive by design. Learn more at the Bitcoin block hashing algorithm wiki.
Can I use SHA-256 for passwords?
Technically yes, but don't use raw SHA-256 for passwords. It's too fast — a GPU can compute billions of SHA-256 hashes per second. Use a dedicated password hashing algorithm like bcrypt, scrypt, or Argon2 instead. OWASP's cheat sheet explains when to use which algorithm.
Is my data sent to a server?
No. Everything runs locally via the Web Crypto API in your browser. No data ever leaves your machine. You can open the Network tab and confirm zero requests are made.
What's the difference between SHA-256 and SHA-512?
SHA-512 produces a 512-bit (128-hex-char) output vs SHA-256's 256 bits. Both are secure. SHA-512 can be faster on 64-bit processors but produces a larger output. SHA-256 is the default recommendation for most applications per current NIST guidelines.
Related Tools
References: NIST Cryptographic Standards and Node.js Crypto documentation.