Nothing here yet
Compute SHA-256, SHA-512, SHA-384, SHA-1, MD5 and CRC32 for files or text, and compare the result against a published value. Everything runs in your browser — nothing is uploaded.
Questions
Is my file uploaded?
No. Reading and hashing both happen in the browser. Nothing remains once the tab is closed.
How large a file can it handle?
SHA algorithms require the whole file in memory through the browser's hashing API; files above roughly 500MB may fail on some devices. MD5/CRC32-only jobs read 2MB slices. Calculations stay on your device and normally run in a worker separate from the interface.
The value does not match the publisher, but it should
A single differing byte changes everything, so check first that the pasted value is complete. Also hash the file exactly as downloaded — opening and re-saving it in an editor can change line endings or text encoding, and that changes the hash.
Can I use this to store passwords?
No. SHA-256 and similar hashes are designed to be fast, which is the wrong property for stored passwords. Use a purpose-built scheme with a salt and a tunable cost, such as bcrypt, scrypt or Argon2.
Why do the text box and the file give different values?
Browsers normalise every line break in a text box to LF. A file saved with CRLF line endings is genuinely different data, so it hashes differently. Use the file mode to check a file.
How should I verify a download?
Note the value from the publisher, hash the downloaded file here, and compare the two. ⚠️ Because the value and the file come from the same place, an attacker who controls that place can replace both. Verification protects against corruption in transit and against a copy from somewhere else — not against the publisher being compromised.
Is comparing the first and last few characters enough?
For catching accidental corruption, yes. Against deliberate tampering, no: an attacker can aim for a value whose visible ends match. When tampering is the threat, compare every digit — copy the value from here and diff it as text.
Can it hash a whole folder?
No. A hash maps one byte sequence to one value, and there is no agreed way to fold several files into one. To check a folder, archive it first and hash the archive — bearing in mind that archives embed timestamps, so rebuilding one from identical contents produces a different value.