B3sum

b3sum Plugin

Compute BLAKE3 cryptographic hashes for files and streams. The fastest standardized hash function.

Commands

Hash

• b3sum hash file document.pdf — Compute hash of a file
• b3sum hash file file1.txt file2.txt — Hash multiple files
• b3sum hash stdin — Hash data piped to stdin
• b3sum hash file large.iso --num-threads 8 — Multi-threaded hashing

Check

• b3sum hash check checksums.txt — Verify hashes against a list

Options

• --raw — Output raw bytes instead of hex
• --num-threads N — Use N threads (default: all CPUs)
• --no-mmap — Disable memory mapping

Full Access

• b3sum _ _ — Passthrough for advanced options

Usage Examples

• "Get the BLAKE3 hash of this ISO file"
• "Verify the integrity of downloaded files using checksums.txt"
• "Pipe a file through b3sum and get the hash"
• "Hash multiple files at once with multi-threading"

Installation

cargo install b3sum

Key Features

• Blazing fast: BLAKE3 is the fastest standardized hash
• Multi-threaded: Automatically uses all CPU cores
• Streaming: Can hash data piped from stdin
• Check mode: Verify file integrity from hash lists
• Raw output: Output raw bytes for further processing
• Non-interactive: All operations are one-shot CLI commands

Comparing Hashes

# Generate hash
b3sum myfile.bin

# Check against stored hash
echo "abc123...  myfile.bin" > myhash
b3sum --check myhash