SHA3 Hash Generator

Paste a message into this SHA3 hash generator and you get back a SHA3-256 hash, a fixed 256-bit fingerprint that changes completely if even one character of your input changes. Built on SHA-3, the newest hash function in the Secure Hash Algorithm family, the tool runs in your browser, so your text never has to leave your machine.

How the SHA3 Hash Generator Turns Text into a Digest

A hash tool takes a message of any length and returns a digest of fixed length. The SHA-3 family, also called Keccak after the sponge design it was selected from, offers four digest sizes: 224, 256, 384 and 512 bits. The generator reads your input, converts it to bytes using the input encoding you pick, runs those bytes through the Keccak algorithm, and prints the result as hexadecimal or Base64 text. The same bytes always produce the same digest, on any device, in any programming language. The free wordpress password hash generator runs entirely client-side — nothing you enter or generate is ever stored or transmitted.

Three properties make the output useful. First, the digest is deterministic, so two people hashing the same message get the same value. Second, it is one-way: nobody can work backwards from a digest to the original message except by guessing inputs, which is the idea behind preimage resistance. Third, it resists collision attacks, meaning finding two different messages with the same digest is computationally out of reach for a well-chosen digest size.

The sponge construction in four moves

Unlike SHA-1 and SHA-2, which use a Merkle-Damgård chain, SHA-3 uses the sponge construction. The sponge works on a 1,600-bit internal state and moves through four stages. Padding comes first, as described below. During absorbing, each block of your message is XORed into the state, and a 24-round permutation scrambles it. Before the last block, the message gets a small domain-separation suffix and a simple 10*1 padding pattern so that every length lines up with the block size. During squeezing, the sponge reads the digest out of the state, and it can keep squeezing if more output is needed.

The reference implementation of Keccak was released to the public domain, which is one reason you can find the same function in browsers, databases, command-line tools and hardware modules. Each of the 24 rounds applies five steps to the state, named theta, rho, pi, chi and iota. Together these steps form the permutation that gives the sponge its mixing power: theta spreads every bit's influence across columns, rho and pi rotate and rearrange lanes, chi adds the non-linearity that stops algebraic shortcuts, and iota breaks symmetry with a round constant. Because the same permutation is reused for every block, hardware designers can build one small circuit and loop it, which keeps the function cheap to implement.

The split of the state matters for security. Of the 1,600 bits, the rate portion is the part your message touches, and the capacity portion stays hidden. For SHA3-256 the rate is 1,088 bits (136 bytes) and the capacity is 512 bits, which is exactly twice the digest size. A longer digest therefore means a larger capacity and a smaller rate, so SHA3-512 processes fewer message bytes per permutation than SHA3-224 does.

Generate a SHA3-256 Hash Online Step by Step

To generate sha3 hash values with this page, you only need a message and a few seconds. Follow the same order every time so results stay comparable between tools. The free mysql password hash generator runs entirely client-side — nothing you enter or generate is ever stored or transmitted.

1. Type or paste your message into the input box.
2. Choose the input encoding: plain text (UTF-8), hex or Base64. Pick hex only when the characters you typed are already encoded bytes.
3. Select the digest size: SHA3-224, SHA3-256, SHA3-384 or SHA3-512.
4. Choose the output format, hex or Base64, then press the generate button.
5. Use the copy hash button and paste the digest where you need it.

This free online tool also works as a quick checksum calculator: hash a file's contents or a configuration string, then compare the digest with a published value to confirm nothing changed. Unlike a typical SHA-3 hash generator that reads plain text only, it accepts hex and Base64 input as well, so think of it as a sha3 calculator with an encoding switch. The SHA3 digest it prints updates every time you change the message, the size or the output format, so you can watch the effect of each option live.

Choosing the right input encoding

Most mismatches between two hash calculators come from the input encoding, not from the algorithm. The text release-2026.10.05 is 18 bytes in UTF-8, and those 18 bytes are what get hashed. If you select hex input while typing ordinary letters, the generator reads the characters as encoded bytes and returns a different digest. Accented letters and emoji take more than one byte in UTF-8, so a message with a single "é" has more bytes than characters.

Hex or Base64 output

Both formats show the same bytes. A SHA3-256 digest is 32 bytes, which is 64 characters in hex and 44 characters in Base64. Hex is the usual choice for checksum files and command-line output, while Base64 is common in HTTP headers and JSON payloads.

Worked Example: A SHA3 Hash Calculator on One Message

Take the message release-2026.10.05, 18 bytes of UTF-8 text. A SHA3 hash calculator returns these digests for the four SHA-3 sizes:

The same SHA3-256 digest in Base64 is OrglJa+9ciqYbSuYeoO1fm2zTVbSa1kwKK9hvjojKak=. Notice that the hash size is independent of the message length: an 18-byte message and an 18-gigabyte file both produce a 256-bit SHA3-256 digest.

The avalanche effect

Change the last character of the message from 5 to 6 and the SHA3-256 digest becomes 0a56ca2e14dcd3715a4afbee8f2ecde3c21e0b980b2b716ac3dd608b953b1e35. Comparing the two 256-bit values bit by bit, 133 of 256 bits differ, which is 52.0 percent. A good hash function flips about half the bits for any small change, so two similar messages give digests with no visible resemblance.

\(\text{hash size} = \text{bits per digest}\), so the share of flipped bits is:

$$\text{changed share} = \frac{133}{256} \times 100 = 52.0\%$$

Checking a Webhook Payload with a SHA3-256 Hash Generator

Marta, a backend developer in Porto, receives a test webhook from a payment vendor whose documentation promises that every body is signed with a SHA3-256 digest. The vendor's sandbox page lists the expected value for its sample body, 7e352f618d71d84a97f2a976948c3016562c03fab46cf109db48f103a90d5df4, and her handler keeps rejecting the request.

She opens the generator, pastes the 50-character body {"order":48213,"amount":"129.40","currency":"EUR"} exactly as logged, leaves the input encoding on UTF-8, and picks SHA3-256 with hex output. The digest that appears starts with 727f06e5, which is not the 7e352f61 she expected. Because the vendor's sandbox page is the trusted source for the expected value, the mismatch has to be in her bytes, not in the algorithm.

The logger had appended a trailing newline, so she was hashing 51 bytes instead of 50. She deletes the final line break, and the output changes to 7e352f61...0d5df4, an exact match for all 64 hex characters. Before shipping, she tries the Windows ending too: with \r\n the digest becomes 4dcc1da9...96bf03, so she now knows both variants fail.

• Result: 50 bytes of body produce the expected 256-bit SHA3-256 digest.
• Reference point: FIPS 202 fixes the digest at 32 bytes, 64 hex characters, so any shorter value would point to a truncated copy.
• Next action: her handler now hashes the raw request bytes before any logging or trimming happens, and she adds the 50-byte sample as a unit test.

SHA-3 vs SHA-2, SHA-1 and MD5: Which Hash Function to Pick

NIST published SHA-3 as a standard in FIPS 202 on August 5, 2015. It was not meant to replace SHA-2, because no significant attack on SHA-2 has been shown. It exists because the successful attacks on MD5 and SHA-1 convinced NIST that the toolbox needed a structurally different hash algorithm as a backup.

For new designs, either SHA-256 or SHA3-256 is a sound choice. SHA-3 is the better fit when you want a function that is immune to length-extension attacks by construction, or when your protocol already uses Keccak-style primitives.

SHA3-256 vs Keccak-256

These two names cause the most confusion. SHA3-256 is the standardized function from FIPS 202. Keccak-256 is the earlier Keccak submission, which uses a different padding byte. The two produce different digests for identical input, and Ethereum-style systems use Keccak-256, not the NIST standard. If a tool's output doesn't match yours, check which of the two it computes before suspecting a bug.

Security Strength of Each SHA-3 Hash Size

Security in a hash function is measured in bits of work an attacker needs. For a digest of d bits, the standard gives roughly d/2 bits of collision resistance and d bits of preimage resistance. SHA3-256 therefore offers 128 bits against collisions and 256 bits against preimage attacks, while SHA3-512 offers 256 and 512 bits.

\(\text{collision strength} = \frac{d}{2}\) and \(\text{preimage strength} = d\), where \(d\) is the digest size in bits.

Quantum computers and hash size

Grover's algorithm gives a quantum computer a square-root speedup when searching for preimages, which roughly halves the effective strength. Against that, SHA3-256 would still keep about 128 bits of preimage resistance, and SHA3-512 about 256 bits. Collision search benefits much less. Choosing a longer digest is the standard way to keep margin against quantum attacks. Speed is rarely a concern in practice: Keccak runs at roughly SHA-2 speed in software, with hardware acceleration available on some CPUs, so hashing a short message in your browser feels instant.

Put this to use in the generator by choosing SHA3-224, SHA3-256, SHA3-384 or SHA3-512 in the digest size selector: pick SHA3-256 for general integrity checks, and move to SHA3-512 only when a protocol or policy asks for the larger margin.

What a SHA3-256 Hash Is Used For, and What It Is Not

A SHA3-256 digest is a cryptographic hash, a compact fingerprint of data. It is not encryption: nothing is hidden and nothing can be decrypted, because the digest does not contain the message. Real encryption always has a key that reverses it, and a hash never does. In cryptography the two jobs are kept apart: encryption protects confidentiality, while a hash proves integrity. Typical uses of these hash functions include:

• Verifying a downloaded file against a checksum published by the vendor.
• Confirming data integrity of backups, build artifacts and configuration files.
• Building content addresses and deduplication keys for databases.
• Supporting digital signatures, where the digest rather than the whole message is signed.
• Feeding protocols and implementations that need a modern hash algorithm alongside SHA-2.

Why you should not store passwords as plain digests

A bare SHA3-256 digest is fast to compute, so attackers can test billions of guesses per second against leaked passwords. Real password hashing needs a salted, deliberately slow function such as Argon2, scrypt or bcrypt. A plain digest also gives no authentication, because anyone can recompute an unkeyed hash after tampering with a message. When you need to prove who produced the data, use a keyed construction such as HMAC or a digital signature.

Verifying data with a trusted source

You can verify data only when the expected digest comes from a trusted source, such as the vendor's official site, a signed release note or your own earlier record. Hash the same bytes, compare every character of the two digests, and treat any difference as a failed check. A digest copied from the same untrusted page as the download proves nothing.

Why Your SHA3 Hash Calculator Result May Differ

When two tools disagree about the same message, the cause is almost always the input rather than the algorithm. Work through this list in order:

• Wrong algorithm. Confirm the expected function is SHA3-256 and not SHA-256 or Keccak-256. For release-2026.10.05, SHA-256 gives ff7eb53c0071aa83e2a48badcad5e92d31e0fe185fd95f0dded396fd8993cd63, nothing like the SHA3-256 value.
• Different bytes. Check the encoding. A hex field and a text field hash different bytes for the same visible characters.
• Line endings. A trailing newline, or Windows \r\n instead of Unix \n, adds bytes and changes the digest entirely.
• Hidden whitespace. Copying from a PDF or web page often adds spaces or non-breaking characters.
• File versus text. To hash a whole file, use a file hash tool rather than pasting its contents, since pasting can alter bytes.

Test Vectors and Standards Behind the SHA3 Hash Generator

This generator implements the fixed-length FIPS 202 functions, so its output can be checked against the same published vectors as any other implementation. SHA-3 is a hash algorithm built for compatibility: NIST designed it so that it can be swapped in for SHA-2 wherever an application needs a second, structurally different option. In practice you will meet it in several places. Transport and signature protocols list SHA3-256 and SHA3-512 among their approved digests. Blockchain tooling uses Keccak-style hashing for addresses and for committing to data. Operating systems and libraries ship SHA-3 next to SHA-2 so that applications can pick one through a single interface.

Because the standard is public, independent implementations can be tested against the same published vectors. A well-known check is the empty message: SHA3-256 of zero bytes is a7ffc6f8bf1ed76651c14756a061d662f580ff4de43b49fa82d80a4b80f8434a. If a library or tool does not return that value for an empty input, it is either computing a different function or reading extra bytes. Running the same test against any new tool takes ten seconds and saves hours of debugging later.

How NIST standardized the function

The NIST standard that defines SHA-3 is FIPS 202, titled SHA-3 Standard: Permutation-Based Hash and Extendable-Output Functions. It specifies the four fixed-length functions and the two extendable-output functions, SHAKE128 and SHAKE256. A related set of NIST documents covers keyed uses, such as KMAC, which builds a message authentication code from the same permutation. Agencies and vendors that must follow federal rules can therefore use SHA-3 in cryptography products without custom approval.

The path there began when NIST opened a public hash function competition in 2006, after attacks on MD5 and SHA-1. Keccak entered with 50 other candidates, reached the final round in December 2010, and was named winner on October 2, 2012. Its designers, Guido Bertoni, Joan Daemen, Michaël Peeters and Gilles Van Assche, published the algorithm openly, and FIPS 202 followed in 2015. The secure hash algorithm 3 standard also defines the extendable-output functions SHAKE128 and SHAKE256, which the fixed-length generator does not use. Winning the competition did not make Keccak a drop-in clone of earlier hash functions: it was chosen precisely because its sponge design differs from the SHA-2 family, which gives security teams a fallback if a weakness is ever found in either design. The competition also left a lasting habit in modern cryptography of choosing standards through open public review rather than behind closed doors, and Keccak's wide cryptanalysis during those years is a large part of why people trust it today.

Privacy and Browser-Based Hashing

This hash tool computes digests locally in your browser, so the message is not uploaded to a server. That matters for security when you hash anything sensitive, such as an internal identifier or an API payload. Good security practice still says to avoid pasting live secrets into any web page; a one-way digest of a short, guessable secret can still be brute-forced offline, which is a weakness of the input rather than of the Keccak permutation.

Developers and programmers can reproduce every result on this page from a command line or library, which makes a quick cross-check easy. Python's hashlib.sha3_256(), OpenSSL's sha3-256 digest and most language standard libraries all follow FIPS 202.

Frequently Asked Questions

What's the difference between SHA-3 and Keccak?

SHA-3 is the NIST-standardized version of the Keccak algorithm (FIPS 202, 2015), which made small padding changes during standardization -- so plain "Keccak-256" and "SHA3-256" actually produce different hash values for the same input. Keccak-256 is specifically still used by Ethereum and some other blockchain systems that adopted it before the SHA-3 standard was finalized, which is why it's offered here separately.

Why would I use SHA-3 instead of SHA-2 (SHA-256/512)?

SHA-3 uses a fundamentally different internal construction (a sponge function) than SHA-2's Merkle–Damgård design, so it doesn't share any of SHA-2's theoretical structural weaknesses -- NIST standardized it specifically as a backup in case future cryptanalysis ever weakens SHA-2. In practice, SHA-256/512 remain considered secure and are far more widely deployed; SHA-3 is chosen when a project specifically wants construction diversity or is required to support it.

Is SHA-3 safe for hashing passwords?

No -- like every general-purpose hash function on this page, SHA-3 is designed to be fast, which is the wrong property for password storage. Use a dedicated slow hash (bcrypt, scrypt, Argon2) for that instead.

Where is Keccak-256 actually used?

Most notably in Ethereum and Ethereum-derived blockchains, for address derivation, transaction hashing, and Solidity's built-in keccak256() function -- a legacy of Ethereum adopting Keccak before NIST's SHA-3 standardization finalized the padding change.

Is my text sent anywhere?

No. The hash is computed entirely in your browser using the js-sha3 library -- nothing is transmitted to a server or stored.