The need for an online responsive tester

There were and still there is numerous responsive testing method available both offline and online. They are all good in their own right serving a lot of different stages of the responsive testing realm. That stage we were interested in was the front-end building stage. That part of the workflow when we are compiling the layout, choosing the media queries, and target the devices or device groups. Usually we do it in localhost with the design already done and waiting to be built. Well, on that stage we were missing some things and a handful of those missing things led us to think of a comprehensive solution for our responsive design to test.

Created for testing OnDevice

We’ve created OnDevice, the online responsive design tester, to ensure an accurate testing experience for our web design works. It’s an experience of a device lab translated into the online world. We call it thoughtful. So what does thoughtful mean as a responsive design tester? Well, for us, it means taking into account all the details that would alter the testing result compared to a real device.

What was responsive testing and what was missing?

Before we built our own online responsive tester, we used everything we could find to test our responsive design. Although we have not necessarily found everything in the whole wild world, the tools and methods listed below are those we did find and used quite often. In addition, other missing pieces made us think of something smoother.


  • Had no any nearby
  • Can’t correct and re-test right there
  • Limited number of devices
  • Limited opening hours


  • Testing per device was slow
  • Increasing line of shoppers behind us
  • Making low quality notes in a hurry
  • Shop stuff's embarrassing look


  • Constant switching between resolutions
  • No device type assigned to the resolution
  • Not particularly presentable
  • Occupy a lot of screen when open


  • One resolution to test at the time
  • Applying the resize to all opened window
  • Getting lost in popups
  • Screen size only without physical size


  • Schematic device images
  • Non comparable device listing
  • Usually not client-ready interface
  • Most ignore retina display, scrollbar width


  • Very slow loading
  • Load only one device at the time
  • Test only mobiles devices
  • Offered in package we don’t need

What an effective online responsive design
tester has to ensure for us

Compare the devices

and quickly correct any misalignment

For the sake of efficiency, it was crucial for us to be able to quickly scan through the result of the online responsive testing by comparing the devices. This way we could see whether a modification applied in the stylesheet was put under the right media query and didn't mess up other views. If it did mess them up, we wanted to be able to correct quickly and re-test the page with a single refresh.

Comparable devices for online responsive testing

Scrollbar width for online responsive testing

See the breakpoints applied

as on real devices

We needed to see whether our breakpoints were set correctly when we were targeting a specific device or device group. This was especially so when the design we needed to test online for responsiveness contained custom graphic to resize carefully. That’s were we needed to take into account the scrollbar width, because 17– 20px can be crucial when it comes to applying the media queries.

Show the result to the clients

in a simple and appealing way

The client-facing part of the design process was always one of the most sensitive parts of our workflow. Thus, we needed to show the responsive test results online to people who had no interest in layout explanations and no time to listen to the stories about what would fit in the viewport and/or how much to scroll to reach a particular section. The other very important lesson for us was that clients perceive the design very differently when a black device image is wrapped around the page, simply by altering the contrasts of the design.

Presenting online responsive testing to clients

Big devices for online responsive testing

Testing laptops and monitors

to have the whole picture

When we were designing on a 2–3K pixel wide monitor, even the 1920px one looked like a small screen, let alone laptops. We needed a device range that contains several other office devices under 2–3K pixel, but above the tablet size to be able to test online for different enterprise equipment.

How the online responsive testing looks like now

To solve all the problems we faced during our online responsive design testing sessions, we created an interface for OnDevice on which the test result is displayed: horizontally · by device size · with real device picture · in a scalable form.

OnDevice for online responsive design testing


Seeing the final look of my design in the way that it would actually look on real devices is a great help for me. Also, it makes it a lot easier to show my ideas and progress of work. ( NICOSIA - JanisBar - 27.01.2017 )

OnDevice, a thoughtful responsive tester

Being thoughtful covers three main things. First, OnDevice shows the test results according to the real device sizes, so you can see whether you set your break points correctly. This also means you’ll see the most optimal picture of what the client sees on its device, decreasing the number of change requests afterwards. Second, OnDevice shows multiple devices in one horizontal viewport, making it possible to compare them. Because you don’t need to switch between devices, you get a clear overview of how your responsive design looks across multiple devices, making bug searching and fixing much more effective. Third, OnDevice is a responsive testing tool prepared for presentations. By switching from the edit view to the presentation mode, you can hide the developer toolbar and show the responsive overview of your work to stakeholders.

Online responsive testing now

So here we are now, testing online our responsive design on our ergonomically designed tester tool, OnDevice. It’s also our first live product, constantly improved and shaped toward the highest efficiency based on the members’ feedback. There is much thought in OnDevice and great hope that it can make your responsive testing flow more efficient. Take a look and try it for yourself—maybe it can.