Free Developer Tool — 100% Client-Side

Hash Generator

Name: Hash Generator - WebUtil
Author: WebUtil

Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from any text input. Fast, secure, and browser-based.

Input Text

MD5

—

SHA-1

—

SHA-256

—

SHA-512

—

Enter text and click Generate Hashes.

What Is a Hash Function?

A cryptographic hash function takes an input and produces a fixed-size string of bytes (a hash). The output is deterministic — the same input always produces the same hash — but the function is one-way: you cannot recover the original input from the hash. Our free hash generator online computes MD5, SHA-1, SHA-256, and SHA-512 hashes instantly in your browser.

MD5 vs SHA Algorithms

MD5

128-bit hash. Fast but cryptographically broken. Suitable for checksums and non-security applications. 32-character hex output.

SHA-1

160-bit hash. Deprecated for security use. Still found in legacy systems and Git. 40-character hex output.

SHA-256

256-bit hash. Industry standard for security. Used in SSL/TLS, blockchain, and password hashing. 64-character hex output.

SHA-512

512-bit hash. Strongest in the SHA-2 family. Used in high-security applications. 128-character hex output.

Why Hashing Is Irreversible

Hash functions are designed to be one-way functions. They use mathematical operations like bitwise rotations, logical functions, and modular addition that discard information at each step. Given a hash, the only way to find the original input is to try every possible input (brute force) until you find a match — which is computationally infeasible for strong algorithms like SHA-256.

Use Cases for Hashing

Password Storage — Store hashes of passwords instead of plaintext. (Always use a dedicated password hashing function like bcrypt in production.)
Data Integrity — Verify that files haven't been tampered with by comparing their hashes.
API Security — Sign API requests with HMAC using a shared secret key.
Digital Signatures — Hash messages before signing them with asymmetric cryptography.
Blockchain — SHA-256 is the core hashing algorithm behind Bitcoin and many other cryptocurrencies.

Is MD5 Still Safe?

MD5 is not safe for security-sensitive applications. Researchers have demonstrated collision attacks where two different inputs produce the same MD5 hash. For password storage, use bcrypt, argon2, or SHA-256 with a salt. However, MD5 remains widely used for file integrity checks, data deduplication, and non-security checksums where collision resistance is not critical.

Cryptographic hash functions are mathematical algorithms that transform arbitrary-length input data into a fixed-size bit string (a digest or hash) in a strictly deterministic, one-way manner. A secure cryptographic hash exhibits four primary properties: 1) Determinism (the same input always produces the exact same hash), 2) Pre-image resistance (it is computationally infeasible to reverse the hash to find the original input), 3) Second pre-image resistance (it is infeasible to find another input that yields the same hash), and 4) The Avalanche Effect (changing a single bit of input radically alters the resulting hash). Hash algorithms are fundamental to digital signatures, SSL/TLS certificates, Git commit integrity, blockchain consensus, and file checksum verification. MD5 (128-bit) and SHA-1 (160-bit) are now cryptographically broken due to practical collision attacks and must never be used for security. SHA-256 and SHA-512 (from the SHA-2 family) represent the current industry gold standard. Importantly, raw cryptographic hashes like SHA-256 should NEVER be used for user passwords without salting and iteration: attackers can crack raw hashes at billions of guesses per second using rainbow tables and GPUs (use key-derivation algorithms like Argon2 or Bcrypt instead). WebUtil's Hash Generator computes MD5, SHA-1, SHA-256, and SHA-512 hashes simultaneously in your browser using the native Web Crypto API with zero data upload.

How to Do This in Code

async function hashString(algo, str) {
  const buf = await crypto.subtle.digest(algo, new TextEncoder().encode(str));
  return Array.from(new Uint8Array(buf)).map(b => b.toString(16).padStart(2, '0')).join('');
}
hashString('SHA-256', 'hello').then(console.log);

import hashlib
hashlib.md5(b'hello').hexdigest()
hashlib.sha256(b'hello').hexdigest()

import "crypto/sha256"

h := sha256.Sum256([]byte("hello"))
fmt.Printf("%x", h)

echo -n 'hello' | md5sum
echo -n 'hello' | sha256sum

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Related Guides & Tutorials

Security 6 min read

Hash Generator Guide: MD5, SHA-1, SHA-256, and SHA-512 Explained

Learn how cryptographic hash functions work, the differences between MD5, SHA-1, SHA-256, and SHA-512, and when to use each.

Hash Generator FAQ

What is a cryptographic hash function and how does it work?

A cryptographic hash function takes any text or binary input and processes it through mathematical compression functions to produce a fixed-length string (digest) that cannot be reversed.

Can a SHA-256 or SHA-512 hash be decrypted or reversed?

No. Cryptographic hashes are one-way mathematical operations, not encryption. They contain no decryption key. The only way to find the original text is guessing (brute force or dictionary attacks).

Why are MD5 and SHA-1 no longer considered secure?

Researchers have discovered collision vulnerabilities in both MD5 and SHA-1, meaning attackers can generate two different files that produce the exact same hash. Use SHA-256 or SHA-512 for security.

What is the difference between hashing and encryption?

Encryption is a two-way function designed to hide data with a secret key so it can later be decrypted. Hashing is a one-way function designed to verify data integrity and identity without revealing original contents.

Why should I use Bcrypt or Argon2 instead of SHA-256 for user passwords?

SHA-256 is designed to be fast, enabling attackers to test billions of password guesses per second on GPUs. Password hashing algorithms like Argon2 and Bcrypt are deliberately slow and memory-hard to prevent brute-force attacks.

How does WebUtil compute hashes in the browser?

WebUtil uses the browser's native window.crypto.subtle.digest API, executing cryptographic math on your local CPU without sending any data over the network.