Available in all subroutines.

Returns the separator needed by the querystring.filter and querystring.filter_except functions.


set req.url = querystring.filter(req.url,
"utm_source" + querystring.filtersep() +
"utm_medium" + querystring.filtersep() +

Try it out

querystring.filtersep is used in the following solution recipes, which show real world use cases. Click RUN to provision a Fastly service, execute the code on Fastly, and see how the function behaves.

Normalize requests

Improve cache performance by normalizing requests. Filter and reorder query params, convert to lowercase, filter headers, and more.

User contributed notes

We welcome comments that add use cases, ideas, tips, and caveats. All comments will be moderated before publication. To post support questions, visit our support center and we'll find you the help you need.