Rules / viewport rules

viewport.content.device

Default

error

Plugin

viewport

The viewport content includes width=device-width.

Why: Without width=device-width, phones lay out the page at a fixed width instead of the screen width.

When off: viewports without it pass.

<!-- ✗ Fails -->
<meta name="viewport" content="initial-scale=1" />

<!-- ✓ Passes -->
<meta name="viewport" content="width=device-width, initial-scale=1" />

References

• MDN: The viewport meta element: width=device-width sizes the page to the screen.