Available inall subroutines.

Returns a hash value of the string key, using seed, and returning a number between from and to.

The underlying hash function might not offer cryptographic properties or collision resistance guarantees.


declare local var.hurl INTEGER;
set var.hurl = fastly.hash(req.url, 0, 0, 1023);

Try it out

fastly.hash is used in the following code examples. Examples apply VCL to real-world use cases and can be deployed as they are, or adapted for your own service. See the full list of code examples for more inspiration.

Click RUN on a sample below to provision a Fastly service, execute the code on Fastly, and see how the function behaves.

Enable features gradually

Avoid a huge inrush of traffic to origin caused by gradually applying changes that affect the cache key, like segmented caching, over hours or days.