Hash Generator

The Web Crypto API deliberately omits MD5, and this tool is not going to work around that.

MD5 has been cryptographically broken since 2004. Collisions — two different inputs producing the same hash — can be generated in seconds on a laptop. Researchers have demonstrated colliding executables, colliding PDFs, and a forged certificate authority.

SHA-1 is also broken; the SHAttered attack produced two colliding PDFs in 2017. It is included here because verifying legacy checksums and Git object ids still requires it, but it should never be used for anything new.

For integrity checking, use SHA-256. It is fast, universally supported, and has no known practical attacks.

For passwords, use none of these. Cryptographic hashes are designed to be fast, which is exactly what an attacker wants when testing billions of guesses. Use Argon2id, scrypt or bcrypt — algorithms deliberately made slow and memory-hungry.

A published checksum lets you confirm a file arrived intact and unmodified. The process is simple, and its limitation is important.

Drop the file in, pick SHA-256, paste the published value, and the comparison is done for you — which beats eyeballing sixty-four hex characters and missing a transposed pair.

What a matching hash proves: the file is byte-for-byte what the publisher hashed. No corruption in transit, no truncated download.

What it does not prove: that the file is safe. If an attacker controls the download page, they control the checksum printed on it too, and can serve a malicious file with a matching hash. Checksums protect against accidents and mirrors, not against a compromised source.

Signatures do prove authenticity. A GPG signature is verified against a key you already trust, so an attacker would need the private key rather than just write access to a web page. Where a project publishes signatures, prefer them.

Files here are hashed locally by your browser, so size is limited only by memory — nothing is uploaded.