---
title: "Critical CSS Inlining"
category: studio-standards
status: recommended
url: https://webspecification.com/spec/studio-standards/critical-css-inlining/
source_repo: undefined
licence: CC-BY-4.0
---
# Critical CSS Inlining
> Automating the extraction and inlining of above-the-fold CSS.
## What is it?
The process of extracting the exact CSS rules required to style the elements visible in the user's initial viewport (above-the-fold) and injecting them directly into a `
```
## Verification
- Run Lighthouse. If "Eliminate render-blocking resources" flags your main CSS file, critical inlining is not working correctly.