BLAKE2b File
Compute the BLAKE2b (512-bit) hash of any file. Streamed in chunks, so large files work without freezing the browser.
Calculate the BLAKE2b hash of a file. Streams the file in your browser. Read more Show less
What is BLAKE2b file hashing?
BLAKE2b is a cryptographic hash function published in 2012 by Aumasson, Neves, Wilcox-O'Hearn, and Winnerlein. It produces a 512-bit (64-byte) digest, shown as 128 hexadecimal characters. It is faster than SHA-512 in software and provides the same security level, making it a popular alternative in modern systems.
BLAKE2b is used in libsodium, Argon2, Zcash, and many other modern protocols. It is not standardized by NIST, but its design was published openly and it has been extensively analyzed.
How to use
Drag, click, or paste a file. The tool streams the file in chunks and computes BLAKE2b as it reads. It also accepts a URL; the server must allow cross-origin requests.
Keyed mode
BLAKE2b supports a keyed mode for message authentication, often called BLAKE2b-MAC. This tool uses the unkeyed default, which is what most file-integrity workflows expect. For keyed authentication, use HMAC-SHA-256 or one of the KMAC tools.
FAQ
Are files uploaded?
No. Everything runs locally in your browser. Files are streamed in chunks and never sent anywhere.
Why is my checksum different from the vendor's?
Confirm you have the exact same file. A re-download that includes any trailer or redirect can produce a different hash. Read the file in binary mode; text modes can alter line endings.
How large a file can I hash?
Any size your browser can open. Files are streamed in chunks, so memory use stays flat regardless of file size.
Can I verify a signed download with this?
It verifies the file matches the checksum you were given. The security of the verification depends on where the checksum came from: HTTPS from the vendor is far better than a checksum posted in a forum.
Command line equivalent
# Linux (coreutils b2sum)
b2sum myfile.bin
# Python
python3 -c 'import hashlib; print(hashlib.blake2b(open("myfile.bin","rb").read()).hexdigest())'
# OpenSSL 3.x
openssl dgst -blake2b512 myfile.binThe server must allow cross-origin requests (CORS). If it doesn't, download the file and use the File tab.