Free · Private · Client-side

SHA-256 Hash Generator

Generate secure SHA-256 hashes from text or files. Perfect for checksums, file verification, and ensuring data integrity across systems.

Generated values never leave this device.

Text to Hash

SHA-256 is a one-way 256-bit digest (64 hex characters) — it cannot be reversed. For storing passwords, use bcrypt or Argon2 instead of a bare SHA-256 hash.

SHA-256 Hash

No input

Enter text above to generate SHA-256 hash

Hash Files

Select file to hash (processed locally, never uploaded)

Compare Hashes

Hash 1

Hash 2

Enter hashes above to compare (case-insensitive)

Try These Examples

Expected Hash Examples

SHA-256 Test Vectors

Input: ""
SHA-256: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855

Input: "Hello World"
SHA-256: a591a6d40bf420404a011733cfb7b190d62c65bf0bcda32b57b277d9ad9f146e

Input: "The quick brown fox jumps over the lazy dog"
SHA-256: d7a8fbb307d7809469ca9abcb0082e4f8d5651e46d3cdb762d02d0bf37c9e592

Input: "password123"
SHA-256: ef92b778bafe771e89245b89ecbc08a44a4e166c06659911881f383d4473e94f

About SHA-256 Security

Cryptographically secure - SHA-256 is approved by NIST and widely trusted
One-way function - Cannot be reversed to recover original input
Deterministic - Same input always produces the same 64-character hex output
Collision resistant - Extremely difficult to find two inputs with same hash

Common SHA-256 Use Cases

File Verification

Verify file integrity after downloads. Compare SHA-256 checksums to ensure files haven't been corrupted or modified.

Bitcoin Mining

SHA-256 is the core algorithm used in Bitcoin's proof-of-work mining process and block creation.

Digital Signatures

Create digital signatures by hashing documents before encryption, improving efficiency and security.

Data Deduplication

Identify duplicate content in storage systems by comparing SHA-256 hashes instead of full content.

Password Storage

Part of password hashing schemes like PBKDF2-SHA256, though use bcrypt/Argon2 for direct password storage.

Caching Keys

Generate unique, fixed-length cache keys from variable-length input data for efficient storage systems.

SHA-256 vs Other Hash Functions

Algorithm	Output Size	Security	Use Case
MD5	128-bit (32 chars)	Broken	Legacy checksums only
SHA-1	160-bit (40 chars)	Deprecated	Git commits (legacy)
SHA-256	256-bit (64 chars)	Secure	Recommended standard
SHA-512	512-bit (128 chars)	Very Secure	High-security applications

Generate SHA-256 in Code

JavaScript (Browser)

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

const hash = await sha256('Hello World')
console.log(hash) // a591a6d40bf420404a011733cfb7b190d62c65bf0bcda32b57b277d9ad9f146e

Node.js

const crypto = require('crypto')

function sha256(text) {
  return crypto.createHash('sha256').update(text).digest('hex')
}

const hash = sha256('Hello World')
console.log(hash) // a591a6d40bf420404a011733cfb7b190d62c65bf0bcda32b57b277d9ad9f146e

Python

import hashlib

def sha256(text):
    return hashlib.sha256(text.encode()).hexdigest()

hash_value = sha256('Hello World')
print(hash_value)  # a591a6d40bf420404a011733cfb7b190d62c65bf0bcda32b57b277d9ad9f146e

Terminal Commands

# Hash text
echo -n "Hello World" | sha256sum
echo -n "Hello World" | openssl dgst -sha256

# Hash files
sha256sum filename.txt
openssl dgst -sha256 filename.txt

# Verify file integrity
sha256sum --check checksums.txt

Frequently Asked Questions

Is SHA-256 reversible?

No, SHA-256 is a one-way cryptographic hash function. It's computationally infeasible to reverse a SHA-256 hash to recover the original input. This is by design and a core security feature.

How long is a SHA-256 hash?

SHA-256 produces a 256-bit (32-byte) hash, typically displayed as a 64-character hexadecimal string. Each hex character represents 4 bits, so 64 × 4 = 256 bits.

Can I use SHA-256 for passwords?

Don't use plain SHA-256 for password storage. It's too fast and vulnerable to rainbow table attacks. Use bcrypt, Argon2, or scrypt instead, which include salting and are intentionally slow.

Is SHA-256 the same as AES-256?

No, they're completely different. SHA-256 is a one-way hash function for data integrity, while AES-256 is a symmetric encryption algorithm for securing data that needs to be decrypted later.

What's the difference between SHA-256 and SHA-512?

SHA-512 produces longer hashes (512-bit vs 256-bit) and offers higher theoretical security, but SHA-256 is sufficient for most applications and is more widely supported and efficient.

SHA-256 Best Practices

✓ Do

• Use for file integrity verification
• Implement in digital signature schemes
• Use for blockchain and cryptocurrency
• Generate cache keys from variable data
• Use in HMAC constructions for authentication
• Verify software download checksums

✗ Don't

• Use plain SHA-256 for password storage
• Expect to reverse hashes to get original data
• Use for generating random values
• Hash sensitive data without proper key management
• Assume collision resistance for eternity
• Use for encryption (it's hashing, not encryption)

How to generate a SHA-256 hash

Enter text or upload file

Type your text into the input field or upload a file you want to hash.

Generate hash

The SHA-256 hash is computed automatically as you type, entirely in your browser.

Copy result

Copy the generated SHA-256 hash to use for verification or storage.