BLAKE2b File Hash

Calculate BLAKE2b hashes or keyed MACs for local files and accessible URLs in your browser with selectable digest length and output encoding. Read more

What is BLAKE2b?

BLAKE2b is a variable-length cryptographic hash optimized for 64-bit platforms. This page hashes the raw bytes of a local file or an accessible URL and can return from 1 to 512 bits. It also exposes BLAKE2’s built-in keyed mode for protocols that require a MAC rather than an ordinary file digest.

How to use this file hash calculator

  1. Choose Local File and select a file, or choose URL and enter an accessible file URL.
  2. Select the digest length and Hex or Base64 output.
  3. Leave Key empty for an ordinary checksum, or enter the exact secret key and encoding for keyed BLAKE2b.
  4. Calculate and compare the result with a value obtained through a trusted channel.

Local files are read in your browser and are not uploaded by this tool. URL hashing requires the remote server to permit the browser request, so some cross-origin URLs cannot be read even when they open normally in a tab.

Result example

The displayed value covers the file’s exact bytes. Changing a line ending, metadata stored inside the file, archive contents, or any other byte changes the digest. Renaming a file without changing its contents does not change the result because the filename is not hashed.

Important limitations

Matching a digest confirms equality only relative to the expected value you trust. If an attacker can replace both a download and the checksum beside it, an unkeyed BLAKE2b digest does not establish publisher identity. Keyed mode requires securely shared key material and is not interchangeable with HMAC-BLAKE2b.

RFC 7693 specifies BLAKE2b and its keyed operation. For text or explicitly encoded bytes, use the BLAKE2b text calculator. Compare BLAKE2s File Hash when a format requires BLAKE2s instead.

Frequently asked questions

Why does my result differ from another tool?

Confirm the algorithm variant, digest length, key bytes, and whether the other program hashes the raw file or a transformed representation. A 256-bit BLAKE2b result is not the same algorithm output as a BLAKE2b-512 string truncated to 256 bits afterward.

Can I use the result to verify a download?

Yes, when the expected BLAKE2b value comes from a trusted source and uses the same digest length and keyed or unkeyed mode. The comparison detects changed bytes but does not by itself prove who published the file.

Input
File
Drag and drop the file here or click to select a file. It will process locally and won't be uploaded.
Output
Settings
Hash
Key