Viewport Units vs CSS Units (em, rem)

Developers should learn and use viewport units when building responsive web applications that need to maintain consistent proportions across various screen sizes, such as full-screen hero sections, modals, or typography that scales with the viewport meets developers should use em and rem units when building responsive websites that need to adapt to different screen sizes or user font-size settings, as they provide flexibility and consistency across devices. Here's our take.

Viewport Units

Nice Pick

Developers should learn and use viewport units when building responsive web applications that need to maintain consistent proportions across various screen sizes, such as full-screen hero sections, modals, or typography that scales with the viewport

Pros

• They are particularly useful for mobile-first design, ensuring elements like buttons or containers resize appropriately without complex media queries, and for creating immersive experiences like landing pages that fill the entire screen regardless of device
• Related to: css, responsive-design

Cons

• Specific tradeoffs depend on your use case

CSS Units (em, rem)

Developers should use em and rem units when building responsive websites that need to adapt to different screen sizes or user font-size settings, as they provide flexibility and consistency across devices

Pros

• Em is ideal for component-level styling where sizes should scale with local context, while rem is preferred for global sizing to maintain a consistent scale throughout the document, reducing complexity in CSS
• Related to: css, responsive-design

Cons

• Specific tradeoffs depend on your use case

The Verdict

Use Viewport Units if: You want they are particularly useful for mobile-first design, ensuring elements like buttons or containers resize appropriately without complex media queries, and for creating immersive experiences like landing pages that fill the entire screen regardless of device and can live with specific tradeoffs depend on your use case.

Use CSS Units (em, rem) if: You prioritize em is ideal for component-level styling where sizes should scale with local context, while rem is preferred for global sizing to maintain a consistent scale throughout the document, reducing complexity in css over what Viewport Units offers.

The Bottom Line

Viewport Units wins

Developers should learn and use viewport units when building responsive web applications that need to maintain consistent proportions across various screen sizes, such as full-screen hero sections, modals, or typography that scales with the viewport