Yann Collet · LZ4 · Zstandard · fastest

xxHash calculator

xxHash — extremely fast non-cryptographic hash family by Yann Collet (Facebook/Meta). Used in LZ4 compression, Zstandard (zstd), ClickHouse, and many databases. Pure JavaScript implementation.

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xxHash
 

How to use this tool

  1. Type or paste text into the Input text box — the hash updates instantly as you type.
  2. Pick a variant with the tabs: XXH32 (seed=0), XXH64 (seed=0), or djb2 (classic).
  3. Read the result in the xxHash output, shown as a 0x-prefixed hexadecimal value.
  4. Hit Copy to copy the hash to your clipboard.
  5. Use Clear to empty the box and start over.

Why this tool is helpful

Verify hashes across tools

Cross-check the value from xxhsum or an xxHash library: the same input with seed 0 produces the same XXH32/XXH64 result shown here.

Understand checksums & deduplication

xxHash powers LZ4, Zstandard, and ClickHouse for fast integrity checks and dedup. See the exact values those systems produce.

Compare 32-bit vs 64-bit output

Switch between XXH32 and XXH64 to see the 8-digit vs 16-digit hex output and weigh collision resistance against storage cost.

Speed-sensitive integrity checks

When you need a checksum that is far faster than SHA or MD5, xxHash is the standard choice for non-cryptographic integrity.

Debug hashing in your own code

Reproduce hashes for a known input to confirm your own xxHash implementation matches reference output byte-for-byte.

Stay private

Everything runs in your browser. Nothing is uploaded, logged, or sent to a server — safe for sensitive inputs.

FAQ

What is xxHash?

xxHash is a family of extremely fast, non-cryptographic hash functions created by Yann Collet. This tool computes the XXH32 and XXH64 variants with seed 0, plus the classic djb2.

Is xxHash encryption or a secure hash?

No. xxHash is non-cryptographic and is designed purely for speed, not security. Do not use it for passwords, signatures, or anything where an attacker could forge collisions.

What is the difference between XXH32 and XXH64?

XXH32 produces a 32-bit hash (8 hex digits), while XXH64 produces a 64-bit hash (up to 16 hex digits). XXH64 is wider and typically faster on 64-bit CPUs; choose based on how many bits you need.

What is the seed, and why is it 0?

A seed is a starting value mixed into the hash. This tool uses the default seed 0, matching xxHash reference defaults. A different seed yields a different hash for the same input.

Why doesn't my result match another xxHash tool?

Make sure you are comparing the same variant (XXH32 vs XXH64) and the same seed. Note that XXH3 — the newer generation — is not computed by this page.

Why is the output prefixed with 0x?

The 0x prefix marks the value as hexadecimal, matching how xxhsum and most hash tools print results. The digits after it are the hash itself.

Does any of my data leave my browser?

Never. All hashing happens locally in JavaScript. Your input is not sent to, stored on, or logged by any server.