Is my input sent to a server?

No. The entire computation runs in your browser using the js-sha3 JavaScript library. Nothing is transmitted to any server.

SHA3-256 is part of the SHA-3 family standardized by NIST in 2015. It uses the Keccak sponge construction and produces a fixed-length 64-character hex digest from any input. Despite the similar name, SHA-3 is structurally different from SHA-2.

Is SHA3-256 the same as Keccak-256?

They are related but not identical. NIST made minor padding changes to Keccak before standardizing it as SHA3-256. The original Keccak-256 (used by Ethereum) produces different output than SHA3-256 for the same input.

Why does a small change in input produce a completely different hash?

This is the avalanche effect — a fundamental property of cryptographic hash functions. Even a single-character change cascades into a completely different 256-bit output.

Can I reverse a SHA3-256 hash back to the original text?

No. SHA3-256 is a one-way function. Given only the hash, it is computationally infeasible to recover the original input with current technology.

Does letter case in the input matter?

Yes. "Hello" and "hello" are different byte sequences and produce different SHA3-256 hashes. The tool is case-sensitive.

SHA3-256 Hash Generator

Type or paste any text and instantly get its SHA3-256 hash computed entirely in your browser — nothing is sent to a server.

Input Text

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SHA3-256 Hash

Enter text on the left to see the hash

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Summary

This SHA3-256 Hash Generator uses the js-sha3 library to compute SHA3-256 (Keccak) digests entirely in your browser. Your input text never leaves your device, making it safe to hash sensitive strings. Results are displayed in both lowercase and uppercase hex and can be copied with a single click.

How it works

Type or paste the text you want to hash into the input area.
The tool feeds your text to the js-sha3 library running locally in your browser.
SHA3-256 applies the Keccak sponge construction to produce a 256-bit digest.
The 32-byte result is displayed as a 64-character lowercase hex string.
An uppercase version is also shown for convenience.
Click any copy button to copy the hash to your clipboard.

Use cases

Verify data integrity by comparing SHA3-256 checksums.
Generate deterministic identifiers from text strings.
Hash tokens or secrets locally during development and testing.
Cross-check SHA3-256 digests published by software download pages.
Experiment with the SHA-3 standard without installing command-line tools.
Compare SHA3-256 output against SHA-256 to understand algorithm differences.
Use as a quick sanity check when implementing SHA3-256 in your own code.

Frequently Asked Questions

Last updated: 2026-05-23 · Reviewed by Nham Vu