CryptoHash Studio
Generate SHA-256, SHA-384 and SHA-512 hashes from text or files. Nothing ever leaves your browser.
Input
Hashes
See the avalanche effect live
Edit box B by a single character and watch how much of the SHA-256 output flips — that's the avalanche effect NIST FIPS 180-4 relies on for collision resistance.
How hashing works
A cryptographic hash function takes input of any size and produces a fixed-size "digest" — 256, 384 or 512 bits for the SHA-2 family. The same input always produces the same digest, but even a one-character change produces a completely different one:
SHA-256("abc") = ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad
SHA-256("abd") = a52d159f262b2c6ddb724a61840befc36eb30c88877a4030b65cbe86298449c9
This tool uses the browser's native crypto.subtle.digest() — part of the W3C Web Cryptography API — so hashing happens with the same audited implementation your browser uses for TLS, not a JavaScript reimplementation.
Frequently asked questions
Is it safe to hash sensitive data here?
Yes. Hashing runs entirely in your browser using the native Web Cryptography API (crypto.subtle); no text or file is ever uploaded to a server.
What's the difference between SHA-256, SHA-384 and SHA-512?
They're all part of the SHA-2 family defined in NIST FIPS 180-4, differing mainly in digest size (256, 384 and 512 bits) and internal word size. Longer digests give a larger security margin against brute-force and collision attacks, at a small computational cost.
What is the avalanche effect and why does it matter?
It's the property that changing a single bit of input flips roughly half the output hash's bits. It means near-identical inputs produce completely unrelated-looking hashes, which is essential for detecting tampering and for resisting attacks that try to predict a hash from a similar known one.
Can I hash a file instead of text?
Yes. Select or drop a file and it's read locally with the FileReader API and hashed the same way as text — the file itself is never uploaded anywhere.