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Why Apple might have to put Touch ID on the back of iPhone 8

Way back in January 2015 I wrote about Apple deleting the physical Home button so the company could minimize the bezels in iPhone 8:

Imagine a future iPhone where the screen goes to the edge on both sides, disappearing not at the curve but as the curve. Imagine an iPhone where the FaceTime camera and earpiece take up almost no space, and the screen reaches almost all the way to the top. And imagine an iPhone where the Home button is replaced by some new technology that can still allow for a physical escape to a known state, that can still scan fingerprints and authenticate, but that also lets the screen reach almost all the way to the bottom.

In essence, give people bigger screens without having to give them bigger phones to go with them. Turns out, we got a version of that first with iPhone 7. A non-physical Home button that looked and felt, and forced bezel space, just like the previous one. Back then, though, it felt like the goal was to virtualize and embed the Home button — and the Touch ID sensor that had come to live within it — beneath the screen. That was the next step forward with iPhone 8. (Or whatever Apple calls the next iPhone redesign.)

Back sensor shenanigans

Alleged iPhone 8 schematic from Weibo

A alleged schematic, published on Weibo and picked up by 9to5Mac's Benjamin Mayo, however, shows the Touch ID sensor moved to the back of the iPhone.

Apple typically has more audacious and more pragmatic prototypes. Like James Cameron says, If you set your goals ridiculously high and it's a failure, you will fail above everyone else's success. Audacity drives what's possible. Pragmatism ensures products ship.

So, everyone might well want a Touch ID sensor all but invisibly embedded in the display or as part of the touch bar, but the realities of the technology, including yield and reliability rates, could force concessions. In this case, it could well force the Touch ID sensor out from beneath the screen and around to the back of the phone.

(Not) only Apple

That's what happened with the Samsung Galaxy S8, according to The Korea Herald:

Samsung Electronics' upcoming Galaxy S8 is unlikely to feature on-screen fingerprint scanning after its touch sensor partner Synaptics ran out of time for developing the related technology, industry sources told The Investor earlier this month.On-screen fingerprint was a highly anticipated function for the new phone with a larger-than-ever display screen."Samsung poured resources into Synaptics' fledgling technology last year but the results were frustrating," a source briefed on the matter on condition of anonymity."With the production imminent, the company had to decide to relocate the fingerprint scanning home button to the back of the device at the last minute."A larger screen that covers almost the entire front body is a key feature for the S8. Since last year, Samsung had made all-out efforts to embed a fingerprint scanner under the display to allow users to unlock the phone by placing their finger on the screen, not the physical home button on the bottom.But the efforts went down the drain after California-based Synaptics failed to develop the technology on time. As the result, the home button is widely expected to be relocated to the back next to the rear-facing camera lens.

Apple uses its own technology, built on what it obtained when it acquired Authentec just prior to the launch of iPhone 5s and Touch ID. So, Apple may well have succeeded where Samsung and Synaptics did not.

The back is where a lot of Android devices with virtual home buttons have been putting the fingerprint sensor for a while now. It's not my favorite position, though it can be convenient if set high enough that your index finger naturally falls on top of it. If, for security reasons, you prefer to use less predictable fingers, then your convenience will vary. (Samsung actually put it to the right of the camera module, which I'm not sure I'm wild about.)

On iPhone, that should put the sensor right around where the Apple logo is. On iPhone Plus, right around the middle of the phone. Depending on the ultimate size and ergonomics of iPhone 8, perhaps somewhere in between.

Look, don't touch

iPhone 8 is expected to be announced during Apple's annual September product event in California, perhaps at the soon-to-be-completed Steve Jobs Theater. It could well show up with the Touch ID sensor beneath the screen, all right and proper. This schematic might end up being nothing more than some idle speculation about what a less audacious iPhone 8 would look like.

Likewise, the placement of the Touch ID sensor might not be a long-term concern at Apple any more. Touch ID was designed to make security more convenient. Other technologies, include face recognition and iris scanning can do that as well.

Eventually, we might well move towards more passive, ambient authentication. In that future, the answer to where Touch ID goes could simply be: nowhere.

Rene Ritchie
Contributor

Rene Ritchie is one of the most respected Apple analysts in the business, reaching a combined audience of over 40 million readers a month. His YouTube channel, Vector, has over 90 thousand subscribers and 14 million views and his podcasts, including Debug, have been downloaded over 20 million times. He also regularly co-hosts MacBreak Weekly for the TWiT network and co-hosted CES Live! and Talk Mobile. Based in Montreal, Rene is a former director of product marketing, web developer, and graphic designer. He's authored several books and appeared on numerous television and radio segments to discuss Apple and the technology industry. When not working, he likes to cook, grapple, and spend time with his friends and family.

52 Comments
  • I would prefer the fingerprint sensor on the front, but could live with it on the back of necessary. Posted via the iMore App for Android
  • The biggest issue for me would be phone cases. How could you put a decent case on a phone with the sensor on the back?
  • If there are 3 models (7s, 7s+, 8) and only the 8 has it on the back, I'll likely go with the 7s. I want what the 8 has to offer, but the fingerprint on the back doesn't work for me. For most of my work days, my phone is in a dock at my desk or a dock in my car and a fingerprint scanner on the back isn't helpful. I currently have the 7, but I also have the Pixel (secondary phone for testing) and thought maybe I'd slowly adapt to that, but that didn't happen. I'll take the 7s for now and wait for them to perfect the under the screen tech.
  • I seriously do not want to have to pick my phone up to log into it. I find this a dumb idea as my phone is usually sitting on my desk next to my mouse pad during the work week. :(
  • I have the same use case.
  • No Apple. Just no. I'm honestly not too concerned with what Samsung is doing because I purchased an iPhone. And I'm not a fan of the fingerprint sensor on the back of the phone. I personally don't need a bezel free phone if it means the fingerprint sensor goes to the back. Just feels like Apple Pay would be awkward that way.
  • An unimaginably distressing idea.
  • Please DO NOT put the button on the back, I hate that figure out a way to put it on the front or don't have one at all.
  • I honestly don't think that Apple would even consider the back as an option. They are too invested in the Touch ID and it's simplicity to change course and require inconvenience on the part of it's customer to interact with the device. Yes Google did it with the Pixel and Samsung has done it this year with the S8, but I don't think Apple would follow suit. Like some of the other comments mentioned already it works fine, but you loose the ease of use when your phone is laying down or in a cradle. I don't believe that Apple would take that away.
  • Please don't.. I prefer to keep some bezels and having it on the front than on the back because all of a sudden everyone hates bezels... Between that and the edge display, i don't like what i hear about this iPhone... It looks like a Galaxy copycat now and they are just copying the worst aspect of those phones imo... Who knew i may be more excited about a iPhone 7S!!
  • I much prefer bezels, its more useful as it give me a secure area to hold the phone without touching the highly touch-sensitive screen.
  • No, Apple. There's courage and there's stupid, and your past courage has already been pretty stupid.
  • I wish they can put the TouchID sensor with the shape of the Apple logo on the back. <3
  • I wish they can put the TouchID sensor with the shape of the Apple logo on the back. <3
  • I was thinking the same thing. It's a better placement than dead center like that picture.
    I prefer it on front either way. But like Rene mentioned, maybe they come up with something totally different than TouchID entirely.
  • I had thought of that too. Just have the apple logo made of the virtual button material.
  • Agreed. It is the logical place for it if they can't get it under the screen. I think folks would whine, whine, buy and then exclaim it's an amazing innovation since they'd have a 6+ inch screen on the plus while having it the same size as the 7 Plus.
  • I'm not buying the Samsung Galaxy S8 because of that reason. Have the iPhone 7 & SE, I hate the idea of the fingerprint scanner on the back. Everyone is worried about bezzels, keep it on front and slim down the other 3 sides. Make there phone a little thicker!!!
  • I can't see Apple putting Touch ID on the back of the phone for one or two phone revisions it makes no sense. Having Touch ID on the back of the phone changes the user interface too much. This is not apple like. If Apple can't integrate Touch ID into the screen then they should delay that feature until they can. I would prefer this approach too.
  • I have no interest in my phone's fingerprint sensor being positioned on its back. I hope this doesn't come to fruition.
  • I used to have an LG with buttons on the back. Quite honestly, I really liked it. It became very convenient. I find the button placement below the screen difficult for my big hands.
  • Not fussed, either way. Sensor on the back is a pretty common solution these days. Friends with Android phones rave about it. I had the same thought as wabelo above - put it in the Apple logo.
    Also, I still don't get how you're supposed to hit an invisible sensor on the screen with no raised edges. Elegant but impractical.
  • I honestly wouldn't have a problem if they put it on the back as long as they do it right, I have owned phones with the power button on the back and didn't find it as bad as most people have stated. What I'm hoping they do more than anything is bump up the resolution of the 8 to at least 1080p and the + to at least 2K but that's just me.
  • The plus is already at 1080p. At 401 pixels per inch. There would be no point to going any higher. You wouldn't be able to see the pixels. It would however have to. Calculate 4 times the pixels. Slowing the phone down, and wasting battery life. Your not going to see them do that.
  • I think both face and retina security would be clunky. I don't want to have to align my face with my telephone.
  • I hope this is true. I love the fingerprint sensor on the back of my 6P, and this might be the tipping point for the iPhone 8. Posted via the iMore App for Android
  • Why not put the Touch ID sensor inside the Apple logo on the back, covered in Sapphire glass?
  • Why change the design to make it harder to use just for the sake of changing the design.
  • Uhh, no. Here is the fear I have regarding this year's products. I'm afraid the iPhone 8 will just be an expensive version of the Galaxy S8, and the iPhone 7s Plus will be a larger, more expensive version of the G6. That we will go into next year offering a 4 year old design that is being directly competed with by a better product. Worse, Apple seems ok with this! They've gone from the leader to a company that's happy to offer an OK product and hope to cash in on name recognition. Some of you are not old enough to remember, but this is what happened to BlackBerry. The iPhone came out and changed the market, but BlackBerry didn't need to worry, I remember the legions of CrackBerry fans (I was one) who would NEVER buy anything but a BlackBerry. But between the iPhone and the iPhone 4, BlackBerry became irrelevant. Their products stagnated while Apple innovated. I worry we are seeing that now. Samsung got it right with the S6, and improved with the S7 and S8 (Although the sensor is a critical flaw), and during that time, Apple has offered slightly better versions of the same phone and relied on its "CrackBerry" fans and people who don't think about phones to buy those products. Steve Jobs designed the iPhone as a one handed device that played music, made calls, did email, and ran the internet. That was revolutionary. But today we consume video content on our phones. And offering 1080 p in this environment is unforgivable. (My son has an S7 and I'm not sold on the superiority of OLED over LCD) Even in the same form factor, Apple has GOT to offer better hardware than they currently do, or they will continue to bleed sales.
  • "offering 1080 p in this environment is unforgivable" Come on we are tzlking about a phone screen and not a tv! Even Samsung put 1080p by default on the s8 because it is just larketing bullshit for now outside of vr which us a niche use case...
  • It's a phone. Obviously it needs to be a rectangle. There's only so much they can do with the design. Honestly if they find what works design wise I see no reason not to stick with it.
  • " Worse, Apple seems ok with this! " Apple is okay with it because iphone sales tell them their fans are okay with it.
  • "offering 1080 p in this environment is unforgivable" Forgiving for what?? It's a phone!!! 1080p isn't even necessary at all. I can barely remember the last time I saw a video in 720p, I won't even bother with 1080p, it's a waste of data and 480p is more than enough on anything smaller than 6.2 inches screens.
  • I don't care where they put it, as long as iOS 11 has some major innovations. It's the software on iPhones that bores/frustrates me. The hardware is always top-notch.
  • iOS becomes less restrictive with each release, this is the reason why the Jailbreak scene is pretty much dead now. One thing you can be sure of is that iOS 11 will remove restrictions that annoyed you before
  • If TouchID goes to the back, the OLED screen will lose all of its rationale. The only reason Apple might have adopted OLED is to add an extra layer, i.e. TouchID, thanks to the thinness provided by OLED. Since there is no rumor regarding the dismissal of OLED the TouchID won't go to the back and will be integrated into the display. And a bezel free iPhone won't happen, since at least top and bottom bezels are needed to play games.
  • People forget that these bezels serve a very functional purpose. In a lot of situations Apple can be form over function, but they got the bezels right. Maybe they can be reduced from the sides but the top and bottom ones need to stay
  • I rarely touch the bezels on my phone, preferring to hold it on the top and bottom edges in landscape and bottom and sides in portrait. Therefore losing the bezels won't bother me in the slightest. So to paraphrase the late Mr Jobs, maybe you're holding it wrong?
  • Most games are designed for landscape orientation and to hold it that way and play games at the same time you need those bezels. Otherwise your palms obscure the left and right borders of the gameplay area. Forcing game developers to implement "soft bezels" would put unnecessary burden of re-writing all games for the lack of bezels. Such drastic changes are announced sufficiently earlier to the developer community and there is none yet.
  • Not all of us are gamers, so shrinking bezels wont affect us.
  • Mobile gaming is the largest gaming segment overall. I'd say you're in the minority if you're not gaming on your device. Which means the majority would be affected.
  • And just because not all of are gamers doesn't mean we are all holding it wrong either. There are plenty of people that still rely on the bazels as well. As Quis89 mentioned, the majority would actually be affected.
  • No, Apple. Big mistake.
  • I hope it's not on the back. That would be awful. It has to be on the front. If they want to do it the Apple way. They must integrate it into the screen, seamlessly.
  • I will wait until the day of the event. If this anniversary edition of the iPhone is the perfect upgrade but has the fingerprint sensor in the back: I will rush to the AT&T or Apple Store, and upgrade from a 64GB iPhone 6S Plus to a 128GB iPhone 6S Plus. Same phone, still a great processor, all (or most) of the features of iOS 11, comes with a headphone jack, and will probably only be 35 of the cost of this next phone. Sorry Apple, but I am dead set against the iPhone 7, and I use my thumb to unlock my phone, not my index finger. If I wanted a good quality Android with a back fingerprint sensor I'd go with the pixel. Also, why the **** are people against bazels?? Personally I love the fact that there are top and bottom hazels. You wanna watch a movie in 1440p or 4K just watch it on a actual TV. I really don't get how people are able to enjoy a movie in a 5.5 inch screen?? Even the iPad barely justifies doing so,
  • Somebody doesn't like change.
  • So change for the sake of changing?? If so your statement automatically invalidates itself in my Opinion. If I'm going to be embracing change by investing $900+ on a phone, it better be on something I need AND want. So far the next gen iPhone is neither, next question!!
  • They should make the apple logo the touch ID sensor. That way wouldn't need another cutout in cases and would be more natural for most as that's where your fingers rest on the back of the phone when holding.
  • I really don't want Touch ID on the back of the phone. The **** things do not have to be symmetrical. Make the top and side bezel's tiny, leave the bottom big enough to fit the current Touch ID circle. I hate the idea of reducing usability for the sake of some visual appeal (this happens all too often as it is).
    And I don't want a virtual home button, it's stupid, impractical, and should never happen. How are they going to put Touch ID on the back of an iPhone without having to essentially copy Android's horrible virtual buttons for everything? How will you multitask?
  • I think the button on the back would be ok. I have a LG V20 that I play around with, and the button on the back works great. I will admit that the phone has a trusted device feature which means it stays unlocks as long as its in range of my bluetooth headphones (which it almost always is) and it has a "knock knock" feature to wake the screen. It would get a little annoying without that feature.
  • iphone with touch ID in the back? wtf how do i use my phone inside the docking station? galaxy s8 sure no problem they have smart lock. when i am connect to a bluetooth device itll pass the lock screen. but apple is far behind. i honestly had a hard time to buy a iphone 7 plus but when apple continues like that MISSING HEADPHONE JACK i am gone.
  • I honestly don't have a problem with having it under the glass or on the back. I say if yields aren't where they need to be. Release the phone with the sensor on the back. I believe Apple would be in a worse position if they held this model back because of the Touch ID sensor. There will be people that say Apple is copying Samsung or Google. But Apple could easily flip that thought by simply saying how they have done it better. This phone is looking like it will be a huge jump forward for Apple and I have faith that it will have enough going for it that people would overlook the sensor location.