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Clari-Fi uses blurring to simulate the challenges of viewing small icons, images and text on mobile screens


Live demo for mobile screenshots

This page can apply a calibrated level of Gaussian blurring to your mobile screenshot, which you can upload using the button provided below. This enables you to evaluate the visual clarity (i.e. perceptibility) of text, icons, and images that are intended to be viewed on a mobile device.

The process will now be described in more detail for icons, although the same process is also applicable for evaluating other graphical details within a mobile screenshot. This tool can also be used to check banner adverts, or any image file that is full width, but not necessarily full height.

Clari-Fi speeds up the process of developing icons for mobiles, because it enables the visual clarity of these icons to be evaluated on a large screen device, and uses blurring to simulate the challenges of viewing these icons on a mobile device.

Once you have uploaded your screenshot, you should 'zoom in' on the blurred version of the icons that you want to assess, and evaluate whether these icons remain perceptible, quickly and with certainty, despite the applied blurring. This evaluation should be performed by someone whose knowledge of the icons is similar to the users, and not the person who designed the icons.

This tool applies a level of blurring that corresponds to Clari-Fi’s Check Level AA. This level of blurring has been calibrated to a mobile screen that is 68 mm wide (which corresponds to iPhone 6+ / 7+ / 8+).

If graphical details remain perceptible in the blurred version of your screenshot, then the percentage of people who might have difficulty perceiving these details is in the range 0-52%*.

When designing graphical details for mobile devices, this can be considered a minimally acceptable level of visual clarity+.

See the Worked example for more detail on the different Clari-Fi Check Levels.

* Population percentages refer to people who might have difficulty because of visual acuity issues. Some people may have difficulty perceiving these details for other reasons, especially colourblindness.

+ 0-52% of the population having difficulty wouldn’t normally be considered a minimally acceptable level. However, designing for mobile screens is an extreme challenge, and many graphical details within mobile interfaces would be improved if they could at least reach this level of visual clarity.


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