Determine correct breakpoints to wireframe to a responsive website!

1. In which breakpoint sizes should we design responsive websites and apps?
2. How many breakpoints at minimum are recommended for use on a responsive website?

In which breakpoint sizes should we design responsive websites and apps?

With a huge number of device targets and screen sizes across the Windows ecosystem, rather than optimizing your UI for each device, we recommended designing for a few key width categories (also called "breakpoints"): Small (smaller than 640px) Medium (641px to 1007px) Large (1008px and larger)

How many breakpoints at minimum are recommended for use on a responsive website?

While there is no universal set of breakpoints or best practices, you should use at least 3 breakpoints for the most device flexibility (see illustration). When designing for specific breakpoints, consider the content you have. Don't build media queries for devices, built it for content.