The Toothbrush Test & Mobile Onboarding

Note: If you’re seeking information about the cost of poor onboarding to the user funnel or specific tactics that comprise stellar onboarding design, this post may not be for you.

The good news is there’s plenty of information about these areas from Samuel Hulick at The even better news is that in just 3 minutes, you will learn a quick test that you (designer or not) can execute to examine the effectiveness of your mobile app onboarding. Now read on!

Perhaps a few months back you heard about Google CEO Larry Page’s “Toothbrush Test” as an approach to deciding which companies to acquire.

In ten weeks, I’ve developed my own version of the Toothbrush Test, focused not on acquiring companies (though I’d love to have Page’s billions to make that possible for myself) but on improving mobile app onboarding processes.

Onboarding is Hard

Onboarding is one of the toughest design challenges.

When done poorly, it prevents users from accomplishing the one thing that enables access to all the awesome stuff an app can do.

When done well, it engages users quickly and inspires a sense of trust that infuses itself each time you request more information or action.

And when done in a mediocre manner? It unfortunately leans closer to the “failure” category than the “success” category.

This means there’s a very slim chance of success.

On Golf and Design

Another way to think about this is the Golf Rule, applied by Steve Krug to the concept of visual hierarchy. Like golf, a game in which a person of questionable sanity attempt to get a tiny ball in a tinier hole with one of 14 sticks**, onboarding seems deceptively simple at first glance yet is truly difficult. It also means there are only a few ways to get it right, and it’s glaringly obvious to outsiders when it’s done wrong (even when the golfer know how much they’ve improved their form).

**My fascination and frustration with golf warrants a separate post.

TL;DR: Onboarding is SUPER important to usage and growth, and is very easy to screw up.

Why Should You Believe Me

As a UX Designer, it’s part of my process to be in-the-know about the latest apps. It also doesn’t hurt that I’m seeking my next gig and checking out new companies — an incredibly motivational factor to encourage continual new-app downloads by your truly. ;)

The bottom line is that I’ve tried out several apps each week, for 10 weeks. Originally, this started as a test to stay relevant, gleaning the latest developments in visual and interaction design. Instead, I gleaned something much more useful: a get-smart-fast education in onboarding.

The Toothbrush Test

The key to the Toothbrush Test is to do it first thing in the morning. Ssshhh. Trust your Toothbrush Test Guru.

Wake up. Stretch. Do your thing. But don’t get too energized. You should still be a bit sleepy. Sleepiness is key.

Now go brush your teeth, like you do every day. (You do brush your teeth every morning, right?)

While brushing your teeth, bleary-eyed and already maxing-out your cognitive load with the simple brushing motion, get out your phone.

Open a new app. (Or somehow engage the onboarding process for *your* app, which you’ve likely already got sitting on your phone.)

Now: sign up for the product/service/whatever.


My system of scoring is simple. So simple that I don’t write it down, because generally speaking, it’s intuitive and easy to remember who wins and who loses.

Da Rules:

Do I have to slow down my tooth-brushing movement while signing up?
Negative points.

Do I have to stop brushing my teeth completely?
Automatic fail.

Can I continue brushing my teeth without interruption?

The reason why this scoring system works is because it accurately reflects the golf rule: much easier to fail than to pass.

I know it’s harsh. Sorry. And you’re welcome.


That’s really about it. Try it out and let me know how it works for you!

Two Notes:

1) The Toothbrush Test is really meant for mobile apps, mostly because it’s difficult to type on a desktop keyboard with one hand. I also wonder whether it’s because it’s easier to get away with complex onboarding on web, since users are more likely to be in a setting where they’re prepared to give more information (seated at a desk, ready to rock). Please voice your thoughts on whether this is the case. I’d love to hear from you!

2) This test still applies if you’re using a powered toothbrush.

3) There are cases in which an app or website needs a hefty onboarding process. There are other in which a company can even benefit from a lengthy signup! The Toothbrush Test is not as helpful for these scenarios.

Now go, be free! Set your alarm clock and a reminder to run the Toothbrush Test bright and early. Share your learnings as a comment, if you would be so kind! I’m curious to see if this helps other people.

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