Mobile Usability for Cats: Essential Design Principles for Felines

by Jakob Nielsen on April 1, 2013

Summary: Feline users require special considerations, including larger tap target zones for paws, continual animation, and audible vocalization.

YouTube has recently been dominated by cats. Even the simplest video of a cat using an iPad app easily gathers millions of viewers.

Bowing to this takeover, our clients are increasingly asking us, "How can we improve our site or app for cats?" With their lack of opposable thumbs and ever-shifting focus, cats are certainly a challenging target audience.

User Research

For our study, we recruited 16 cats as test participants: 4 British shorthairs, 3 Persians, 2 Siamese, 2 Maine Coons, 2 Russian Blues, and 3 cats of “unknown origin.” Of the 16, 4 were declawed and 4 were kittens under 3 months old.

All but three of the cats were allowed outside daily, and all of the test users were experienced with traditional cat toys, including balls and milk-jug rings.

We tested a total of 28 apps and 12 websites, along with apps that were already on the cats' phones or tablets. The study included Android, iOS, and Windows devices.

Usability Findings

The most common usability problem was the tap target size on most interfaces. All of the adult cats were clearly frustrated—even hissing—after accidentally closing the apps they were using.

Even though the cats in the study were smaller than most of the human users we’ve tested, the differences between human and feline anatomies necessitate that we modify our traditional mobile guideline that tappable areas be at least 1cm in diameter. Given the average cat's paw size, we recommend tap target zones of at least 3 cm (slightly larger than one inch), although a Maine Coon might need more due to their unbelievably enormous mitts.

Reasonable accessibility for polydactyl adult cats would require an additional 3 mm.

Photo from usability study showing user reaction to annoying user interface
This test user was clearly irritated—even hostile—after accidentally closing Fruit Ninja.

Other findings:

  • Rapid double and triple taps are common among felines, especially kittens; any response from a multi-tap should be even faster/louder/blinkier than from a single tap.
  • Fitts' Law was found to hold for cats. We expect that it will be confirmed for most other mammalian species in future studies.
    • While beyond the scope of the present research, we suspect that Fitts' Law will not hold for slugs and other crawling critters: their time to reach a target is likely to be linear with the distance.
  • Swiping is expected to work from any and every direction, so ensure that your targets are extra responsive and include corresponding sounds.
  • Animation is especially important, including blinking. In fact, if your site or app doesn't animate, it's pretty much useless.
    • This is a revolutionary finding, considering that blinking has been contraindicated in web design ever since it was #3 on the list of top-10 design mistakes of 1996.
  • A sensory-activated “pause mode” is highly suggested, as nearly half the cats randomly stopped what they were doing to lie down on their devices and stretch, nap, or self-groom for extended periods before resuming their tasks.

Sound Outperforms the Written Word

Other common sources of irritation were the pointless presence of instructions as well as any other use of the English language. While human users rarely read instructions, the users in this study didn’t read at all.

Fishsticks, a Siamese kitten, didn't bother with the helpful hints for Laser Kitten, opting instead to simply bat the screen repeatedly, expecting "immediate results." On the other hand, the best performing app, Fruit Ninja, jumped right into music, spinning watermelons, and responsive “claw marks.”

Screenshot of the home screen in the Laser Kitten iPhone app
Laser Kitten app as tested: Users repeatedly ignored the instructions and went straight to pawing the user interface.

Older Cats Lack Focus

One surprising discovery was the complete lack of attention from the seniors in the study. It was as if older cats didn't even care. One cat, Stephen Pawking, a 16-year-old British Shorthair, stared at the website for Cat Fancy magazine with total disregard, despite its stunning Flash intro. We thus modified the research protocol and gave Mr. Pawking a mouse-catching app, but — due to a life spent solely indoors — he lacked the necessary predatory skills and failed to react. We were, however, able to gain a rather positive reaction to the Call-A-Cat app, which repeatedly plays the sound of a can opener. This simply underlines the importance of sound.

Overall, but especially for younger cats and kittens, the most common feline usage of mobile devices is game play—a finding that was also true in testing young humans. It’s helpful to note that the younger age group tends to tear up devices due to their hyperactivity and sharper claws. For testing purposes, a strong case and screen protector are advised.

Beyond Human–Computer Interaction

When we broaden the user pool beyond the anthropocentric view, it’s no surprise that many of the findings from human–computer interaction (HCI) research must be modified.

Our initial research with feline users has provided a baseline of FCI guidelines. As always, we recommend that you conduct your own user testing if you’re designing for cats. Given this target audience’s reputation for being notoriously independent-minded, they’re less likely than humans to be accepting of bad design.

Learn More

New full-day course based on our work testing non-verbal users: User Testing with Mind Reading: The Superior Alternative to the "Talk Out Loud" Technique.

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