STRING, read-only.

Available inall subroutines.

The file extension specified in a URL.

If multiple file extensions are present, only the last extension is used. For example, given the path /, req.url.ext would be txt. If no file extension is present, the value will be an empty string.

This variable is updated any time req.url is set.


In the request, req.url.ext will contain html.

Try it out

req.url.ext 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.

Create image transform presets

Use custom, predefined classnames like large, medium, small, teaser, thumb, or article to control Fastly Image Optimizer and optionally prevent end-user access to native properties like 'width'.

Deny access to certain file types

Check for specific URL extensions and deny access with a 403.