 Connor Clark [X](https://twitter.com/cjamcl) [GitHub](https://github.com/connorjclark)
Published: Oct 8, 2025
Tap interactions may be [delayed by up to 300 milliseconds](https://developer.chrome.com/blog/300ms-tap-delay-gone-away) if the viewport is not optimized for mobile.
## How to pass this insight
At the initial render of the page, a `` element that is optimized for a mobile device must be present.
Here's an example of a passing meta viewport element:
The criteria for a viewport optimized for mobile are the following:
- `width` attribute is set to something (`device-width` is most common)
- `initial-scale` attribute is set, and its value is \>= 1
## Additional references
- [viewport insight source code](https://source.chromium.org/chromium/chromium/src/+/main:third_party/devtools-frontend/src/front_end/models/trace/insights/Viewport.ts)
- [Responsive Web Design Basics](https://web.dev/articles/responsive-web-design-basics#viewport)
- [Using the viewport meta tag to control layout on mobile browsers](https://developer.mozilla.org/docs/Web/HTML/Guides/Viewport_meta_element)
- [Chrome Speed - First Input Delay Changes in Chrome 91](https://chromium.googlesource.com/chromium/src/+/main/docs/speed/metrics_changelog/2021_05_fid.md)