How to use the SHA-256 Hash Generator
- 1. Add inputType text, or choose a file such as an installer or ISO.
- 2. Pick optionsAlgorithms, hex or Base64 output, an optional HMAC key, and a checksum to compare.
- 3. Generate hashCopy the hash and see whether it matches.
What SHA-256 is for
SHA-256 turns any input into a fixed 256-bit fingerprint, shown as 64 hex characters. Change one byte and the hash changes completely, and nobody can work backwards to the input. That makes it ideal for checking downloads: if the SHA-256 of your file matches the one on the publisher's website, the file arrived intact. With a key, HMAC-SHA256 proves a message came from someone who knows the key, which is how many APIs and webhooks sign requests. Everything is calculated in your browser; nothing you enter is uploaded. Hashing uses your browser's built-in Web Crypto engine, so even large files are fast.
SHA-256 alone is not a password hash: it's designed to be fast, which helps attackers guess. Passwords need slow, salted algorithms such as Argon2 or bcrypt.
Worked example
The text Uncodemy has the SHA-256 hash 43a7bc00327630648e083bfc29e2ed47a4ca6e5c9708d0d7846e99d0b3cfd16c. Paste that into Compare with and the tool shows a match; change the text to uncodemy and the hash, and the comparison, change completely. We checked SHA-1, SHA-256, SHA-384, SHA-512, MD5 and HMAC results against Python's hashlib on 49 different inputs, including Hindi text and emoji.
Good to know
- Text is hashed as UTF-8; Windows line endings (\r\n) are turned into \n unless you untick that option.
- Checksums on websites are usually lowercase hex; Base64 is common in HTTP headers and Subresource Integrity.
- SHA-1 and MD5 are included only for checking old checksums.
Frequently asked questions
Is my file uploaded?
No. It's read and hashed in your browser, which is why there's no upload wait.
Why does my hash differ from another tool?
Usually line endings, a trailing newline or text encoding. Try unticking the line-ending option or hashing the file instead of pasted text.
Is the SHA-256 generator free?
Yes. You can open the SHA-256 generator and use every option without signing up. When you generate a hash for the first time, we ask once for your name and WhatsApp number; after that it, and every other Uncodemy tool, opens straight away.