Here’s Why Siri Can’t Run on Previous Generation iPhones


In a blog post from iFixit it’s noted that the iPhone 4S features a tweaked proximity sensor, basically an infrared LED capable of detecting how close the user’s face is to the screen. iPhones have always incorporated proximity sensors that prevent accidental input by turning the device display off during phone calls (when the phone is raised to the users ear), but Siri’s “Raise to Speak” feature requires that the device be ready to sense proximity to the user’s face at all times.

From iFixit:

The iPhone 4S  has a neurotic tendency of always wondering how close your face is. As long as the screen is activated, that IR sensor will be shining brightly. Siri is ready and waiting to answer her master’s beck and call at any time. So whenever the screen is active, the proximity sensor is active too. Thus, whenever you raise the iPhone 4S to your face, Siri is ready to take orders.

In a YouTube post, iFixit shows how the iPhone 4’s proximity sensor is only activated while on a phone call, while the sensor on the iPhone 4S is active whenever the device’s display is on.

Ongoing efforts to port Siri to other iOS devices has given hope to enthusiasts eager to port Siri to previous iPhone models, but while the Siri port may eventually prove feasible, the full experience will only be capable on the iPhone 4S with its tweaked proximity sensor.


  • lucss

    So ? What does this have to do with anything,  if they port it to previous generation iphones we wont be able to use the proximity sensor okay so use it like you would normally would a couple of inches from your face or using the earphones right?

  • Very lame reason…especially none of the Apple Siri demo video talk to Siri by “raise to speak”

  • Anonymous

    Is the proximity sensor not software controllable in the iPhone?

  • Lee

    Yeah, it seems like ppl are grasping at straws now to validate Apple’s comment that there are no plans to activate Siri on other devices. This proximity sensor difference is entirely software controlled. Proof of this is that turning off the “Raise to Speak” option makes the proximity sensor function exactly as it does on every other iPhone. I can’t figure out why all of these blog sites keep publishing this stuff as if it is fact with no critical analysis whatsoever.

  • Bryan

    It’s clearly a cash grab and all the more reason to jailbreak your phone.

  • Anonymous

    What a load of crap! Like that’s the only way to use Siri. The settings screen above clearly shows you can just hold the home button instead.  And as already pointed out, the video demos show headphone use without raising the phone.  Why make up reasons? Apple knows that this is the sexiest difference in the 4S – the internal changes don’t grab the attention of the average consumer, and if you give this feature away, you give away sales.
    I don’t like it either, but I don’t feel the need to make up a BS “technical limitation” to explain why it “can’t” be on older hardware.

  • Buklau

    I don’t understand how this is a hardware limitation? If both iPhones have sensor, all you would need to do is make it so the iPhone 4 LED sensor lights up as well when the screen is on.

  • Even if apple WAS planning to open it up to all devices, they wouldn’t confirm it to someone via email, that’s not how this stuff works.

    And Lee, turning it off changes it back to how it normally functions, but what about turning it on? It’s called backward compatible. I can play an Xbox game on my 360, but I can’t play a 360 game in an original Xbox.

    Your testing doesn’t prove anything.

  • Daniel Lee

    This problem can easily be overcome, so far its just BS.  If they have admitted that there is a sensor in the iPhone 4, then there is no reason that it can’t be changed in the software to have it turned on when the screen is active.

    Apple, you have really disappointed me and a lot of other loyal users.  Stop dropping the ball and give all iPhone users Siri.  So far I have yet to hear of any hardware limitation as to why Siri cannot be used on my iPhone 4.

    I hope your stock drops like a rock until you give us what we want.

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  • Matt

    … umm.. it proves exactly what he says it proves – that it’s software controlled. Which means there is no reason they “can’t” do it.

  • ARrrr

    The google app’s voice search on iphOne had raise to speak

  • Patrick

    Honestly, this has to take the prize for the dumbest blog post I’ve ever seen on this site.

    Are you seriously saying that iPhone 4 users wouldn’t take Siri if the hold-it-to-your-face trick didn’t work? Seriously??? I’m thinking a poll of iPhone 4 users would reveal about a 99-1 disagreement with you, Old Weird Harold being the lone dissenter.

  • Brad17

    Ahaha no nick is exactly right. While its possible that it is software controlled (and knowing apple, it probably is), his method is terrible. That’s like saying its possible to have flash on my 3GS because an iPhone 4 can have it turned off. There’s no proof that it’s possible to make the previous iphone’s proximity sensor respond as the iPhone 4s’ and there’s no proof of it not being possible either.

  • Anonymous

    u mad bro?

  • It doesn’t PROVE that it is software controlled. It’s just as possible to have new hardware that’s able to turn OFF its new feature.

    Like I said, this is just like a backwards compatiblity debate.

    My 360 can run my original Xbox games.

    My original Xbox can’t run 360 games because of many factors that I don’t believe I need to go into.

    The 4S sensor can be turned off from constant polling.

    Just because it’s a sensor, doesn’t mean it operates in the exact same way as the iPhone 4, 3GS or whatever sensor.

    Now don’t get me wrong, I’m not saying that this is the case. Hell, it probably isn’t. Just like Video Recording or HDR wasn’t the case. But that doesn’t mean that ANYONE has the ability to say for certain there is not a hardware difference in the sensor.

    If iFixit has proved the hardware is *exactly* the same, that answers that question. But have they?

  • Anonymous

    You’re exegetically analysis is mistaken. Re-posting the last paragraph:

    “[W]hile the Siri port may eventually prove feasible, the full experience will only be capable on the iPhone 4S with its tweaked proximity sensor.”

  • Anonymous

    It’s also keeps the user experience consistent across devices. Having Siri work one way on the iPhone 4S and another way on the 4 and 3GS would be un-Apple like.

  • Patrick

    The title of the post has “… Why Siri Can’t Run…”. To link the notion of “Can’t Run” of such an advanced, industry leading feature such as Siri to such a relatively minor “Raise to Talk” sub-feature is, at best, disingenuous.

    There’s plenty of precedent for Apple bringing a reduced capability feature to an older handset. Just ask the iPhone 3G folks to list them for you.

  • Anonymous

    You still seem to missing the point of the article. That there IS a hardware difference that would affects the user experience from a 4 to 4S, Again, I’ll highlight: “While a Siri port may eventually prove feasible, the full experience will only be capable on the iPhone 4S with its tweaked proximity sensor.”

    The article doesn’t say anything about iPhone 4, 3GS, 3G user not wanting Siri, as you suggested.

    The article is not an op-ed, it’s reporting the facts as discovered by iFixit.

    I agree that the title should of been clearer. In hindsight I wish I hadn’t used the word ‘Can’t’.

    As for precedent, I’m tying to think of a software feature that Apple permitted on a 3G iOS update that was limited by a hardware feature. I can’t think of any.

    For instance, muti-tasking wasn’t on the 3G, since the processor wasn’t fast enough. 3G users didn’t get HDR due to lower quality camera. FaceTime wan’t on the 3G since it lacks a front facing camera. And 3G users didn’t get a compass since there is no gyroscope.

    The article is agnostic about reduced capacity. Of course the 3G has reduced capacity, but there’s a difference between lacking a feature and having a feature that works differently between devices. The former is unavoidable if we’re to see improvements, the latter is a thoughtful decision made by Apple.

    The last line is my opinion.

  • Patrick

    Yes, you’re saying that there’s a difference in proximity sensors between the 4 and the 4S and therefore Siri’s “Raise to Speak” feature won’t work as well on the 4. Is that it? If so, then, yes, I get it. I got that as soon as I initially read your post.

    You say this is not an op-ed piece, that it’s reporting facts. Well, maybe. Certainly the difference in proximity sensors is a fact if we are to believe iFixit (and I do). But your headline was “Siri Can’t Run” on previous phones. That doesn’t seem to be a “fact” to me. I know you now say you regret using the word “Can’t”, but you did, and I was reacting to what you actually wrote.

    If the title of your post had been “Enhanced iPhone 4S Proximity Sensor Improves Siri’s User Experience” (or some such), I would not have had a problem at all. But here you were telling previous generation users that they weren’t going to be getting Siri (It Can’t Run!!) because of a hardware difference that is marginal, to say the least (my opinion). If Apple had said that they were bringing Siri to iPhone 4 but it would not be including the “Raise to Speak” feature *at all*, there would still be much rejoicing in the streets. Hardly a sentence would have been written about the feature downgrade (my opinion) because people would be too busy using and playing with their great new toy.

    My feeling is that your headline is symptomatic of the general state of affairs in the Apple blogoshpere. Every tiny little factoid is blown so far out of proportion that readers are left wondering what is fact and what is fiction. The skeptic in me thinks that the article got a lot more hits with the words “Can’t Run” in the title than it would have with a truly factual headline like the one I proposed.

    As for Apple’s history in limiting features in legacy models, I’m very confused by your statements. Don’t you think the software features of multi-tasking or HDR photos was affected by hardware, namely inferior memory or CPU speed?

  • Anonymous

    In trying to be timely I wrote a bad title.
    I feel good about the content of the post.