xxHash64
Compute a xxHash64 digest of any file, on your device.
Runs on your device. The file is never uploaded.
xxHash64 prints a 64 bit non-cryptographic digest as 16 lowercase hex characters, beside the name of the file it came from. Both halves of the seed stay at 0, since the row passes your bytes and offers no field to change them. Nothing here resists a deliberate collision, so keep XXH64 to cache keys and corruption checks.
Questions
Is xxHash64 a cryptographic hash?
No. XXH64 is a fast non-cryptographic hash for tables, checksums and de-duplication. Anyone who wants to can construct two inputs with the same value, so it says nothing about tampering. If you need that guarantee, use SHA-256 hash or BLAKE3 hash.
How long is the output?
64 bits, printed as 16 lowercase hex characters, after a line with the title and your file name. There are no options. That is the same visible length as the xxHash3 tool here, which makes the two easy to mix up, so record which algorithm produced a value you plan to compare later.
Is xxHash64 the same as xxHash3?
No. XXH64 is the older algorithm and XXH3 is the newer one, and they give different values for the same input despite both being 64 bits here. Pick the one that matches whatever produced the value you are comparing against.
What seed is used?
The default of 0. This tool calls hash-wasm xxhash64 with your file bytes and nothing else, so both halves of the seed stay at zero and the result lines up with other implementations left at their default. There is no field on this page to change it.
Why does another tool report a different number?
Two usual causes. It seeded differently, or it hashed different bytes, which happens when one side hashes a pasted string and the other hashes a file that ends with a newline. Some tools also print the value as a decimal integer rather than hex.