---
title: req.is_background_fetch
summary: null
url: >-
  https://www.fastly.com/documentation/reference/vcl/variables/client-request/req-is-background-fetch
---

**Type:** BOOL  
**Access:** read-only

**Available in:** all subroutines

Whether VCL is being evaluated for a _stale while revalidate_ request to a backend.