SHA-256 & SHA-512 Hash Generator Online | Text & File Checksum Calculator

This tool computes SHA-256 or SHA-512 hashes in real time using the browser's built-in crypto.subtle.digest() API — the same Web Crypto API used by security professionals. Select your algorithm, enter text or upload files for batch hashing with CSV export, and choose between UTF-8, Hex, or Base64 input encoding. Results appear instantly in Hex or Base64 format.

Algorithm Comparison

Algorithm	Output Size	Hex Length	Speed (64-bit)	Best for
SHA-256	256-bit (32 bytes)	64 chars	Fast	File checksums, blockchain, TLS
SHA-512	512-bit (64 bytes)	128 chars	Faster on 64-bit	High-security hashing, password KDFs

Code Examples

Compute SHA-256 hash with Web Crypto API:

// Browser — SHA-256 hash
const message = new TextEncoder().encode('hello world');
const hashBuffer = await crypto.subtle.digest('SHA-256', message);
const hashArray = Array.from(new Uint8Array(hashBuffer));
const hashHex = hashArray.map(b => b.toString(16).padStart(2, '0')).join('');
console.log(hashHex);  // b94d27b9...

# Python — SHA-256 hash
import hashlib
hash = hashlib.sha256(b'hello world').hexdigest()
print(hash)  # b94d27b9...

Security Notes

• SHA-256 is collision-resistant — no practical collision attacks exist; suitable for digital signatures and certificates.
• Never use SHA-1 for new projects — it is deprecated and vulnerable to collision attacks since 2017.
• Hashing is not encryption — SHA hashes are one-way functions; you cannot recover the original input.
• For password storage, use a KDF — SHA-256 alone is too fast for password hashing; use bcrypt, scrypt, or Argon2.

Related Tools

Need to compare two hashes side by side? Try the Hash Compare tool. For HMAC generation with a secret key, see the HMAC Generator. You can also derive keys from passwords using the KDF Hash Generator.