Hash Generator

How to generate a hash online

jsonsql.dev generates cryptographic hashes instantly in your browser. No data is sent to any server — your text and files stay on your machine.

Example

Input text:

Hello, World!

Hash outputs:

MD5:    65a8e27d8879283831b664bd8b7f0ad4
SHA-1:  943a702d06f34599aee1f8da8ef9f7296031d699
SHA-256: dffd6021bb2bd5b0af676290809ec3a53191dd81c7f70a4b28688a362182986f
SHA-512: 374d794a95cdcfd8b35993185fef9ba368f160d8daf432d08ba9f1ed1e5abe6cc69291e0fa2fe0006a52570ef18c19def4e617c33ce52ef0a6e5fbe318cb0387

Supported hash algorithms

• MD5 — 128-bit hash, widely used for checksums. Not recommended for security purposes due to known collision vulnerabilities.
• SHA-1 — 160-bit hash. Deprecated for cryptographic use but still common for file integrity checks and git commit hashes.
• SHA-256 — 256-bit hash from the SHA-2 family. Industry standard for digital signatures, certificates, and blockchain.
• SHA-512 — 512-bit hash from the SHA-2 family. Provides maximum security and is faster than SHA-256 on 64-bit systems.

Features

• Generate MD5, SHA-1, SHA-256, and SHA-512 hashes simultaneously
• Real-time hashing as you type with debounce for performance
• Three output formats: hex lowercase, hex uppercase, and Base64
• File hashing via drag-and-drop or file picker
• Compare mode to verify a hash against all computed results
• Shows input size in bytes
• 100% client-side — no data is uploaded to any server
• Dark and light theme support

Hash Generator vs other tools

What is a hash function

A cryptographic hash function produces a fixed-length fingerprint of any input data. Even changing a single character completely transforms the output — this is called the avalanche effect.

Hash functions have three essential properties:

• One-way — a hash function takes any input and produces a fixed-length output (called a digest or hash). You cannot reverse the process to recover the original input from the hash.
• Deterministic — the same input always produces exactly the same hash. Hashing "hello" with SHA-256 will produce the same 64-character hex string every time, on every machine.
• Avalanche effect — even the smallest change to the input (a single bit flip, adding a space, changing one letter) produces a completely different hash output. This makes it impossible to guess the input by looking at similar hashes.

These properties make hash functions essential building blocks in cryptography, data integrity verification, digital signatures, password storage, and content-addressable storage systems like Git.

Hash algorithm comparison

MD5 and SHA-1 are cryptographically broken — do not use them for security. SHA-256 is the minimum recommended hash for integrity verification and digital signatures.

Common use cases for hashing

Hashing is one of the most widely used operations in software engineering and security. Here are the most common real-world applications:

• File integrity verification — when you download software, the publisher provides a SHA-256 checksum. You hash the downloaded file and compare the result to verify no corruption or tampering occurred during transfer.
• Password storage — secure systems never store passwords in plaintext. Instead, they store the hash of the password combined with a unique salt. When you log in, the system hashes your input and compares it to the stored hash. For password hashing specifically, use specialized algorithms like bcrypt, scrypt, or Argon2 — they are intentionally slow to resist brute-force attacks.
• Data deduplication — storage systems hash file contents to detect duplicates. If two files produce the same hash, they are (almost certainly) identical, so only one copy needs to be stored.
• Digital signatures — rather than signing an entire document (which would be slow), the document is first hashed, and then the hash is signed with a private key. The recipient verifies the signature by hashing the document and checking the signed hash.
• Content-addressable storage — Git uses SHA-1 hashes to identify every object (commits, trees, blobs). Docker image layers are identified by their SHA-256 digest. This means the content itself determines its address.
• API request signing (HMAC) — HMAC (Hash-based Message Authentication Code) combines a secret key with a hash function to authenticate API requests. AWS, Stripe, and most webhook providers use HMAC-SHA256 to sign requests.

Hashing in different programming languages

Here are code examples for generating a SHA-256 hash in popular languages and environments:

JavaScript (browser)

async function sha256(text) {
  const data = new TextEncoder().encode(text);
  const hash = await crypto.subtle.digest('SHA-256', data);
  return Array.from(new Uint8Array(hash))
    .map(b => b.toString(16).padStart(2, '0'))
    .join('');
}

await sha256('Hello, World!');
// "dffd6021bb2bd5b0af676290809ec3a53191dd81c7f70a4b28688a362182986f"

Node.js

const crypto = require('crypto');
const hash = crypto.createHash('sha256')
  .update('Hello, World!')
  .digest('hex');
// "dffd6021bb2bd5b0af676290809ec3a53191dd81c7f70a4b28688a362182986f"

Python

import hashlib
hash = hashlib.sha256(b'Hello, World!').hexdigest()
# "dffd6021bb2bd5b0af676290809ec3a53191dd81c7f70a4b28688a362182986f"

Command line (Linux/macOS)

echo -n "Hello, World!" | sha256sum
# dffd6021bb2bd5b0af676290809ec3a53191dd81c7f70a4b28688a362182986f

# Or for a file:
sha256sum myfile.zip

Hash vs encryption vs encoding

Hashing is a one-way operation — you cannot recover the original input from a hash. This is fundamentally different from encryption (reversible with a key) and encoding (reversible without a key).

A common mistake is using encoding (like Base64) for security — Base64 is not encryption and provides zero confidentiality. Another common mistake is using general-purpose hash functions (like SHA-256) for password storage — use bcrypt or Argon2 instead, as they are designed to be slow and resistant to brute-force attacks.

Related tools

Frequently asked questions