xxHash64 is the 64-bit variant of the xxHash family, designed by Yann Collet. It produces 16-character hex hashes at nearly RAM-speed throughput (15-20 GB/s on modern CPUs). It is used for ZFS deduplication, high-performance database hash tables, and fast data synchronization.

How does ZFS use xxHash64?

ZFS uses xxHash64 for block-level deduplication checksums. When ZFS stores or reads data, it computes xxHash64 of each block to detect duplicates, enabling transparent data deduplication that can save terabytes of storage in VM and backup environments.

xxHash64 vs xxHash32: which should I use?

xxHash64 provides better collision resistance at similar speed on 64-bit CPUs. For hash tables with millions of entries, xxHash64 significantly reduces collision probability. Use xxHash32 for embedded/32-bit systems. Use xxHash64 for 64-bit servers and large datasets.

What is the real-world throughput of xxHash64?

On modern CPUs like Intel Core i9 or AMD Ryzen, xxHash64 can achieve 15-20 GB/s on a single core, far exceeding most storage and network speeds. This makes it practical for real-time hashing without becoming a bottleneck.

Is xxHash64 suitable for file deduplication?

Yes, with caveats. xxHash64 is extremely fast for identifying potential duplicates in large datasets. However, because it is non-cryptographic, collisions are possible (though very rare). For guaranteed deduplication, follow xxHash64 matches with byte-by-byte comparison.

Tools

xxHash64|16 hex chars

Input

Output

Hash result will appear here...

0 chars|0 bytes

xxHash64 Hash Calculator — GB/s Throughput Deduplication Hash

Ultra-high-speed 64-bit non-cryptographic hash with GB/s throughput. Powers ZFS storage deduplication, database hash tables, and high-speed data synchronization.

Features

✓Compute xxHash64 checksums online — GB/s throughput for ZFS dedup and database hash tables
✓Real-time 64-bit hash computation with 16 hex character output
✓One-click copy, download as .txt, and uppercase/lowercase toggle
✓Powers ZFS storage deduplication and high-speed data synchronization
✓Hash verification against known xxHash64 checksums
✓100% browser-based with blazing-fast WebAssembly implementation

How to Use

1Type or paste your text into the input box above.
2Your hash digest appears instantly — no page reload needed.
3Toggle UPPERCASE / lowercase to change the hex output format.
4Click the copy icon to copy the hash to clipboard, or use Download to save as .txt.
5Paste an expected hash into the Verify field to check for a match.

Frequently Asked Questions

Related Tools

xxHash32 Hash Generator — Ultra-Fast Database Index Hash

Extremely fast 32-bit non-cryptographic hash approaching RAM bandwidth limits. Used for hash indexing in PostgreSQL, Apache Cassandra, and other high-throughput databases.

CRC32 Checksum Calculator — ZIP/Gzip Data Integrity Tool

32-bit cyclic redundancy check — not cryptographic. The classic data integrity backbone behind ZIP, Gzip, and PNG. Lightning fast but offers zero tamper resistance.

BLAKE3 Hash Calculator — Fastest Merkle Tree Hash (10× SHA-256)

The newest hash algorithm (2020) featuring a Merkle tree architecture for full multithreading. 256-bit default output, up to 10× faster than SHA-256 on modern multi-core CPUs.