Enter the url to your site - local or online: both work - and use the controls to adjust the width and height of your viewport to find exact breakpoint widths in pixels. Then use that information in your media queries to create a responsive design.
Watch the video explaining usage and why it was built.
If your site appears with scrollbars, make sure to check the scrollbar visible box to get the right viewport width and height.
Fork the project or log an issue on github
Built by @rem