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To download Responsive Resize from the Mac App Store, you need a Mac with OS X 10.6.6 or later. Learn More.

Responsive Resize

By Duncan Midwinter

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Responsive Resize is a tool for aiding development and testing of responsive websites. Responsive resize works like a mini-browser with an adjustable viewport which can be altered to match the dimensions of virtually any mobile, tablet or desktop device.

Responsive Resize comes with over 40 preset virtual devices, but you can also add as many new devices as you requires.


History remembers up to 25 sites
Status bar gives load times.
Over 40 preset Mobile, Tablet & Desktop devices
Ability to create as many new devices as you require
Ability to choose from preset User Agent Strings - or enter any string you require
Rotate Device
Ability to quickly adjust the viewport
Increase or decrease the with by a set value
Light or Dark application theme
Fullscreen mode
Devices panel
Preferences panel

What's New in Version 1.3

Added user-agent strings for iOS7 (iPhone and iPad) and user-agent string for Safari 7 (Mac)


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Customer Reviews


This is what we do for a living, build mobile ready responsive websites and this will be an invaluable tool going forwrd. Another great thing is you can add custom devices with sizes. Why is that helpful you ask? Because a lot of our clients are running Internet Explorer 10-11 on crummy low-res hardware and you can’t expling to them why the site doesn’t look good on their system! So, this is a great way to test other resolutions so that you can visually show them whats going on with their site, and make some tweaks if needed to adjust to their resolutions so they are happ.

Great idea. Too bad it doesn’t work.

I purchased this thinking it would be a great solution for developing responsive websites. My problem with it is that much of developing is tweaking your media queries then refreshing the browser to see changes. This app does not refresh properly, even after emptying the cache. Even then, you cannot rely on it to consistently display exactly what you would see on a mobile device.

Also not working for me...

I’m on Mavericks. I was quite excited to start using this app, but as soon as I type a URL into the bar, the app becomes a chromeless web browser, and all the functionality disappears. It works fine on startup, with the developer’s site pre-loaded. As soon as I type anything else into the URL bar, poof, no more app. Maybe something I’m missing, but I need some clearer instruction if so.

Responsive Resize
View in Mac App Store
  • Free
  • Category: Developer Tools
  • Updated:
  • Version: 1.3
  • Size: 2.3 MB
  • Language: English
  • Seller:

Compatibility: OS X 10.8 or later, 64-bit processor

Customer Ratings

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