Giles Butler

Backpacking around the web.


After a few weeks of testing and testing again I’m really proud to announce my first web app – Responsi. A place for testing responsive web designs inside your desktop browser.

I use Chrome for my day to day browsing as well as development and after testing the Responsive Mode in the Firefox dev tools I wanted the same functionality in Chrome and so Responsi was born. I really liked the ability of dragging to resize the viewport window so that was the main feature that I was aiming to replicate. Apart from that I added a few standard preset dimensions and the ability to rotate the viewport when needed. A few little extras include:

  • A bookmarklet to load whatever page your looking at into Responsi
  • iPad support – (Beta)
  • Retina Graphics Ready

Responsi is built in the awesome JavaScript framework Spine and the source code is available to view on github.

Check it out at or if you are Chrome user then its installable via the Chrome Web Store.


  • david shave said:

    Hi, is it possible to add custom screen sizes? I would like to add the boostrap v3 sizes. Great plugin BTW.

    • Giles said:

      Hi David,

      Thanks for the feedback, this has been the most requested feature by far. I’m currently not working on Responsi at the moment though due to working on a startup.
      Once I get round to it I will update this post to let you know.



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