🔒 Cryptographic Hash Generator

Generate secure cryptographic checksums and hashes (SHA-256, SHA-512, SHA-384, SHA-1) directly in your browser using the Web Crypto API.

✓ Free✓ No Signup Required✓ Browser-Based

Input String or Secret

Generated Cryptographic Hashes (Client-Side WebCrypto)

What Cryptographic Hash Generator Does

A cryptographic hash turns input of any length into a fixed-length digest. The same input always produces the same digest, a one-character change produces a completely different one, and the function cannot be run backwards to recover the input.

That last property is what people mean by "one-way", and it is frequently overstated. A hash cannot be reversed by computation, but it can be reversed by lookup: if the input is a common password, an attacker simply hashes a dictionary and compares. This is why hashing a password with SHA-256 is not password storage.

This tool computes MD5, SHA-1, SHA-256, SHA-384 and SHA-512 in your browser using the Web Crypto API where available. Two of those are included for compatibility with legacy systems, not because they are safe.

How to Use Cryptographic Hash Generator

Type or paste your text or secret into the input box
View generated SHA-256, SHA-512, SHA-384, and SHA-1 hashes instantly
Click Copy Hash next to any algorithm to copy it to your clipboard

Algorithm Status

"Broken" means practical collisions have been demonstrated — two different inputs producing the same digest. It does not mean the digest can be reversed, but it does mean the hash can no longer prove that two files are the same.

Algorithm	Digest size	Hex length	Status
MD5	128 bits	32	Broken. Collisions found in 2004; generated in seconds today
SHA-1	160 bits	40	Broken. First public collision (SHAttered) in 2017
SHA-256	256 bits	64	Secure. The general-purpose default
SHA-384	384 bits	96	Secure. SHA-512 truncated, resists length-extension
SHA-512	512 bits	128	Secure. Often faster than SHA-256 on 64-bit hardware
SHA-3 (Keccak)	224–512 bits	varies	Secure. Different internal construction, kept as a hedge

Source: NIST FIPS 180-4 — Secure Hash Standard

Choosing by Purpose

The right function depends entirely on what you are defending against.

Purpose	Use	Do not use
Verifying a download	SHA-256	MD5 — a tampered file can be made to match
Storing passwords	Argon2id, scrypt or bcrypt	Any SHA — they are designed to be fast, which helps the attacker
Signing / certificates	SHA-256 or better	SHA-1 — rejected by browsers since 2017
Deduplication, cache keys	SHA-256, or MD5 if no adversary exists
Message authentication	HMAC-SHA-256	A bare hash of key + message

How to Read Your Result

Why SHA-256 is wrong for passwords

Password hashing needs to be slow. SHA-256 is engineered to be fast, and modern GPUs compute billions per second — so an attacker with a leaked database tests a huge dictionary in hours. Argon2id, scrypt and bcrypt deliberately consume time and memory per guess, and their cost can be raised as hardware improves. They also salt each password, so identical passwords do not produce identical hashes.

What a collision actually breaks

A collision means an attacker can produce two files with the same digest. The practical damage is to any use where a hash stands in for identity: a signed contract swapped for a different one, a verified installer replaced with a modified build. It does not let anyone recover the original input, which is why MD5 is still tolerable for non-adversarial deduplication.

Length extension

MD5, SHA-1 and SHA-256 share a construction that lets someone who knows hash(secret + message) compute hash(secret + message + extra) without knowing the secret. That is why naive "hash the key and the message together" authentication is unsafe, and why HMAC exists. SHA-384, SHA-512/256 and SHA-3 are not affected.

Limitations & Accuracy Notes

Hashing here happens in your browser and nothing is transmitted. Even so, treat pasting live secrets into any web page as a habit worth avoiding.
A hash proves integrity only if you obtained the expected digest through a trusted channel. A checksum published on the same page as the download it verifies protects against corruption, not against a compromised server.
MD5 and SHA-1 are offered for compatibility with systems that still require them. Do not choose either for anything new.
These are unkeyed hashes. They tell you a file has not changed; they do not tell you who produced it. That requires a signature or an HMAC.

Frequently Asked Questions

What is a cryptographic hash function?

A hash function transforms arbitrary input text into a fixed-length string of hexadecimal characters. It is a one-way mathematical function designed to be impossible to reverse.

Is it safe to generate hashes online?

Yes, our Hash Generator uses the browser-native Web Crypto API, processing all data 100% locally on your device without sending text over the internet.

Why does the same input always produce the same hash?

Hash functions are deterministic by design — identical input always produces identical output, which is exactly what makes them useful for verifying a file or message has not changed.

Is MD5 still safe to use?

No — MD5 is cryptographically broken; researchers can deliberately craft different inputs that produce the same hash. It should not be used for security purposes like password storage, though it can be fine for simple non-security checksums.

Can a hash be reversed?

Not by computation — hashing is one-way by design. What is possible is guessing: hashing candidate inputs until one matches. For short or common inputs that is fast, which is why precomputed rainbow tables exist and why salting matters.

Should I use MD5 or SHA-1?

Not for anything security-related. Practical collision attacks exist against both, meaning two different inputs can be constructed to produce the same digest. They remain fine as checksums for detecting accidental corruption in a download, and that is the only use worth keeping them for.

Which algorithm should I use instead?

SHA-256 is the sensible default for general integrity and signing use. For password storage, no general-purpose hash is appropriate however modern — passwords need a deliberately slow function such as bcrypt, scrypt or Argon2, which are designed to make guessing expensive.

Why do I get a different hash than another tool?

Usually a difference in exactly what was hashed. A trailing newline, a different character encoding, or hashing a file versus hashing the text inside it all produce completely different digests — a hash changes entirely when one bit of input changes.

Is my input sent to a server?

No. Hashing runs in your browser using the Web Crypto API.

What is a salt and why does it matter?

A salt is a unique random value combined with each input before hashing. It means identical passwords produce different digests, which defeats precomputed tables and stops an attacker learning that two users share a password. A salt is not a secret — it is stored alongside the hash.

References & Further Reading

NIST FIPS 180-4 — Secure Hash Standard (SHA-1, SHA-2 family) — Normative specification of SHA-1 through SHA-512
NIST FIPS 202 — SHA-3 Standard — The Keccak-based permutation family

By OnlineToolHubs Team • September 2026