Pressing the Side Button to Confirm Payments on iPhone X

Occasionally I notice a burst of traffic to Daring Fireball from Hacker News. It’s always short-lived, because for reasons I’ve never seen explained, Daring Fireball articles always get blacklisted from Hacker News once they hit their front page. It’s apparent that a lot of HN readers do not like my work on the basis that they see me as a shameless Apple shill, but it’s a shame the articles get deleted because I like reading the comments. I feel like it keeps me on my toes to read the comments from people who don’t like Daring Fireball.

Even after being blacklisted from the Hacker News homepage, though, the comment threads still exist. I went through the Hacker News comments on my iPhone X review today, and a few comments about how Apple Pay works on the iPhone X caught my attention:


Apple made some interactions so unintuitive that even I was confused. One example is purchasing an app. Pre-X, you’d tap the “get” button and place your finger on the home button or enter your password. With the X you have to tap the button, look at your device, and then follow the most unintuitive animation to actually press the physical side button.


I’ve had the X for a few days now. The animation to press the physical button totally had me stumped the first few times! Overall I’m a fan (such as great camera and great screen) but some of the new interactions are taking some getting used to.


Yeah the explanation for the side button tap should be considered a straight up bug — I had to google what to do.

These remarks caught my attention because a technically-savvy family member was confused by the same thing the first time they tried to buy an app on their new iPhone X. They showed me the phone with the “Double Click to Pay” animation1 and asked me, “What am I supposed to double click here? It doesn’t work.” What they had tried was double tapping on the “Double Click to Pay” label on screen. When I explained that the animation was pointing to the physical side button, the proverbial light bulb turned on.

This is an interesting design dilemma. The reason why Apple requires you to press the physical side button to confirm a purchase with Apple Pay or in the App Store is because pressing the side button can’t be faked by an app. If it was an on-screen button, a nefarious app could present a fake Apple Pay button. With any normal app, clicking the side button once will always lock the screen, and double-clicking will put you in Apple Pay mode. Only Apple’s own software can override the side button like this. Double clicking the side button to confirm a purchase effectively guarantees that it was a legitimate payment experience.

But: people naturally expect everything they do on an iPhone to be done on screen. The screen is the phone — and that’s even more true with the iPhone X. Even with an animation pointing to the side button on screen, it doesn’t occur to people that they need to do something off-screen to authorize the transaction. They think the affordance on the side of the screen is the button they’re supposed to double tap (and they don’t notice the verbal distinction between “click” and “tap”).

I’m not sure what the solution here is, but I think Apple needs to come up with a better indication — perhaps something more explicit, the first time you encounter it — that you need to click the hardware button, not tap something on screen.

Update: This problem is not new to Face ID. Touch ID has a similar problem. Here’s a note I got today from a friend:

FWIW, Touch ID has been out for four years, and I still see people try to press the fingerprint icon that shows up in the middle of the screen. Can’t count the number of times just in the past six months. I don’t think the X’s initial double-click confusion is a new problem.

Alex fehners:

@jtregear @daringfireball Father in law repeatedly said his Touch ID wasn’t working. He was putting his thumb to the finger print icon on screen rather than the home button.

Iván Cavero Belaunde:

@daringfireball Not entirely a new problem. First time my mom was asked for her fingerprint for iTunes purchases with TouchID, the thought she had to put her finger on the fingerprint on-screen image, not on the home button.

Update 2: Some more commentary.

Joanna Stern:

Yes! On-screen language just needs to be rewritten with an arrow pointing right. I suggest: “Press the damn side button twice. It’s on the damn right edge of the phone.”…

John R. Kirk:

Mock me if you will, but I went weeks without understanding how to confirm payments on the iPhone X. I kept double-tapping the screen. I had to google and read an article before I was able to figure it out.

Apple got this UI wrong. Very wrong.…

Craig Mod:

This was my main crit of @gruber’s otherwise great review — the side-button double-press is really, really, really bad. Unintuitive but more damningly — it’s not fun!

This is in large part because the power-button-across-from-volume-rockers has always felt like a fundamentally wrong design decision. Double-press aside, I take 5-10 unintentional screenshots a day. At least they’re in their own folder now.

The best part of the iPhone X experience really is just how fun it feels — how it’s so totally tactile and responsive and fluid in a way iPhones have never been.

  1. The thing to keep in mind if you watch this animation is that the “Double Click to Pay” animation is aligned perfectly with the hardware side button. ↩︎