Apple Watch diagnostic port John Gruber

Both review versions of the Watch Apple sent to journalists and demo units available in retail stores sport a hidden, undocumented port that Apple chose not to talk about publicly.

Resembling the Lightning connector on iPhones and iPads, it’s reportedly used for diagnostics and direct access to the Watch’s operating system, TechCrunch said in March. Slipping off the bottom strap connector slot of the Watch reveals the hidden port.

Based on social media postings and images Daring Fireball’s John Gruber shared last weekend, it’s basically a 6-dot brass contact array.

In this post, I’m going to lay down a few possible uses for the mysterious port and explain why I think it’s crucial that Watches that’ll be shipping into customers’ hands on April 24 come outfitted with it.

For starters, the port is “very similar” to Lightning I/O, which only uses six of its eight available pins, wrote TechCrunch.

The publication went on to speculate it could possibly open up the market for smart band accessories that would interface with the Watch itself. As you’ll recall, this is how the recently introduced Pebble Time smartwatch allows third-party bands to interact with its software and sensors.

9to5Mac, however, shot down the suggestion, reporting earlier this month that this is “actually a Lightning port being used for testing.” The publication reportedly learned from unnamed sources that it “will not be included on the product shipping to customers.”

But according to a MacRumors reader, in-store Watches have the port present though there’s no telling whether or not these units will be the same as those shipped to customers.

Apple Watch diagnostic port MacRumors

As I mentioned, the port is revealed by slipping off the bottom band.

For what it’s worth, Apple doesn’t acknowledge the port’s existence in any official documentation for users or developers. Moreover, MacRumors’ reader has confirmed that the retail staff had no training on the use of the port.

In my opinion, it’s likely used to install the Watch OS during manufacturing.

What we don’t know (yet) is if we’ll be allowed to restore the Watch software ourselves, which would require a cable connection with iTunes. As for the regular software updates, it’s not been confirmed yet whether Watch firmwares will delivered through the companion iPhone app.

Restoring the Watch to factory settings through desktop iTunes in case everything else fails makes sense to me. Though I’m just speculating here, it would be similar to the Apple TV restore process. As you know, Apple’s set-top box has a port on its back which lets your restore the device to factory settings in iTunes, using a micro-USB cable.

Apple Watch gold connect to iTunes mockup 001

Even if Watch firmwares are delivered over-the-air, an interruption may occur during the software update process, which could potentially render the software useless.

Or, the Watch’s networking stack (Wi-Fi and Bluetooth) may stop working due to an unforeseen software glitch. On that note, memories of a botched firmware update bricking users’ iPhones are still fresh.

Other factors could also cause the Watch OS to break beyond repair. And as we all know, bricked devices must be restored to factory settings, which entails installing the latest software through iTunes.

This is why I think the Watch needs a hardware port.

And even if performing a reset of the Watch’s software will require visiting your Apple Store, Apple’s Geniuses are still going to need a way to connect a malfunctioned device to a computer in order to run diagnostics and apply factory firmware.

Last but not least, the port could potentially make a Watch jailbreak easier.

What’s the hidden port for, do you think?

By the way, if you look closely you’ll notice Apple snuck in the “Assembled in China – Designed by Apple in California” marking inside the other strap slot.

Source: John Gruber

  • Guest

    That port will be used for one thing and that’s jailbreaking

    • The Guy

      Sadly, the jailbreaking days are pretty much over, Apple’s constant updates have brought that to an inevitable end.

      • smtp25

        WTF? You been following JB news, Taig? Sure nothing for latest OS but the last was for two recent releases.

      • The Guy

        What? iOS hasn’t seen a jailbreak since 8.1.2 (betas don’t count), there has been 8.1.3 and we are now on 8.2 about to be on 8.3, and 8.4 is already in beta… and I’v even already tried 9.0. the speed of the updates makes it extremely difficult to do anything.

      • Tommmy

        That’s what they said about iOS 6.3.

      • The Guy

        Please tell us you are joking, there is no such thing as iOS 6.3, LMAO. There is something that hasn’t happened ever in all of iOS history until now and that is a version that is .2 or greater and no updates as quick as what we are getting today. Jailbreak is dead, denial is a powerful thing. The Jailbreak teams got PWNED by Apple, they had a good run, accept defeat and move on.

      • The Guy

        What? Are you on drugs, no such thing as 6.3, lol. You really don’t understand how inherently different the new OS is, especially iOS 9. The hacks better pack up and leave.

      • Tommmy

        Sorry, meant iOS 6.1.3 or similar one. That’s what people said about that version — that jailbreak is done for. But since then both iOS 7 and 8 got jailbroken. Anyway, the one on drugs is probably you seeing how you react to jailbreak. I suggest you go walk outside, talk to someone, find yourself a girl.

      • Antzboogie

        Lol!! What planet are on? Jailbreaking is what pushes the iPhone to its fullest potential. All the awesome Jailbreaks have came up back to back even if it isn’t in the new iOS lol your funny troll.

      • The Guy

        What the hell are you talking about? No one is talking about the jailbreak, lol. We’re talking about the the ability to jailbreak, geez, you 7 year old kids need to learn comprehension.

  • George

    Wow this watch is thick as hell?

    • TechLove

      But it’s thinner than the moto 360.

    • Hussain Alsanona

      it’s pretty light by the way

  • Waleed

    I guess its for restoring Apple Watch

  • Trygve Koren

    Maybe there will be a battery band.

  • Eikast

    The Pebble can set to recovery mode and have a fresh OS install via the Pebble app. There’s no need for them to let customer gain access to the port. That port is mostly used for installing the firmware (bios) for the hardware at manufacturing and probably for testing purposes.

    • I think you’re probably right their. It would make sense that if a problem were to occur with the Watch that when you take it in to an Apple Store they’d hook a cable up to it somehow to do some diagnostics and / or to possibly re-install the firmware.

      As much as people want I jailbreak for the Apple Watch I doubt it’s going to happen assuming it’s as locked down as the Apple TV…

  • The charging cable capabilities is still unknown. It’s possible that you’ll be able to connect that cable to your USB port on a computer, snap to the back of the watch and install the OS through that. But again no one knows until these get int he hands of the general public. As far as this port goes, I’m guessing it has to do with the battery. Either to check the see the cycle time of it or some kind of unlock for the battery itself to be replaced using a specialized cable.

  • praz

    Maybe chargeable bands in the future ? Out of battery just put in a charged band ? Out of the battery in the band put another band ?

    That I feel is a pretty good idea. If Apple ever does it if they are not doing it then please give me credit

    • Andres

      “Your” idea was someone else’s a while ago

    • ReserveStrap

      That is a good idea! We’re currently planning on using the wireless charging on the back (as long as we don’t block the sensors) but the port would be much easier!

      • Andres

        This ReserveStrap account was made just to comment on this post. Pathetic… Lol

      • ReserveStrap

        How is that pathetic, Andres?

      • Marnix Robyns

        don’t bother he’s just a troll

      • Andres

        A troll made the account to look their comment look good. Lmoa

  • joe_l

    What I would like to know is where are the misterious speaker & mic on the iWatch. I can´t see them anywhere on the pics, and nobody seem sto have mentioned that. Plus, how come it is water resistant if its has a speaker & mic?

    • John

      Umm, it’s on the side of the Apple Watch.

      Things can be water resistant and still have speakers/mics…. It’s been done before.

    • Nate McKelvie

      There are COUNTLESS products on the market that are waterproof with both speakers and Microphones. Look at how many bluetooth speakers are on the market alone that have an HFP with a microphone and are completely waterproof

  • simonbratt

    Maybe it’s just to prevent using non-apple bands.

    • „This cable or accessory is not certified and may not work reliably with this Watch”

    • Thought I should photoshop it! haha

  • Chindavon

    Just another example of Apple being one step further than the competition. Maybe used for special straps, LED straps, battery straps, ect. Who knows. I’m sure they have some surprises in store, that they have kept secret in their back pocket.

    • FreeGreezyDoe

      Lol ahead of the competition? Like taking USB ports off of laptops and never updating anything on iPhones except for the camera?

      • Chindavon

        Lol you clowns are getting more and more brain dead by the second.

      • FreeGreezyDoe

        Nothing to contribute so u try to talk sh!t cause ur safe behind the keyboard cool butthurt fanboy

      • Chindavon

        I’ve already contributed in my initial post, but you just blindly ignore most of it. And now you’re a cyber tough guy we all should fear? lol. I’m not going to respond to non-sense like “and never updating anything on iPhones except for the camera?”

      • FreeGreezyDoe

        What else have they updated? U got nothing to say cause ur wrong I wasn’t the one talkin sh!t u were cornball

      • John

        HealthKit, WatchKit, HomeKit, ResearchKit.
        They’ve made NFC/mobile payments easy and popular, something Android has FAILED to do with all of its millions of devices around the world.

      • FreeGreezyDoe

        Lol u tell him im a troll and to leave me alone yet u have to come input ur dumb ish…when was the last time u used health kit home kit or research kit? Never. My point exactly and NFc has been around way before apple put it in their phone sorry kiddo No need to be so butthurt doe

      • John

        Wow, and name calling as well.
        Actually, not dumb ish, I answered your question and you don’t like the answer because I’m right and you’re wrong–again.

        Perhaps you should learn to spell and read because replying next time, you only make yourself look dumb (not that you need much help, troll)

      • FreeGreezyDoe

        I can spell perfect, I choose to not do that mainly for the fact that it takes way longer. I’m not being graded by how I spell on an iPhone site, there’s literally no need to talk with perfect punctuation and grammar if you can understand what im saying…wen I talk like this. Also you never answered me when was the last time u used any of those kits? Never so stop being a butthurt fanboy. I was never wrong to begin with witchyo immature ass talkin bout im right ur wrong wah wah wah go cry urself to sleep now butthurt batty boi

      • John

        Sorry, I didn’t see your question amoungst the failed grammar and spelling.

        HealthKit is used daily as it integrates information from several different applications into one area.
        ResearchKit is currently only available in the U.S. App Store, therefore I do not have easy access to those applications. I’m also not in the ‘at risk’ or ‘at high risk’ categories so there’s no pressing need to download them yet.
        WatchKit can’t be used at the moment since the Apple Watch hasn’t been released but I hope that all developers take advantage of it in some form or another.
        HomeKit is another thing I don’t take advantage of because I’m currently renting and I’m not able to change some of the internal fittings, however, the new premises I’m moving into within the next six months will be HomeKit-enabled.

        Game. set. Match.

      • FreeGreezyDoe

        Bro I said how often do u use it not other companies basically u don’t use any of those things stop being so butt hurt wit yo teenage girl soundin ass who says game. Set. Match. Wit yo volleyball playin potato head lookin ass foh batty boi

      • Nate McKelvie

        Im staying out this argument completely, i have no desire to sit an argue on the internet. But that being said, Im pretty sure Game Set Match, is a tennis term, not volleyball. Don’t quote me on this though, as I may be wrong.

      • FreeGreezyDoe

        Its both but either way both bitch sports

      • Yes

        “I choose to not do that mainly for the fact that it takes way longer.” hahahahaha

        What about your choice to use ridiculously stupid grammar – does that save time too?

      • FreeGreezyDoe

        Word I see nothing wrong wit that please enlighten wit ur pedophile lookin ass and don’t tell me some dumb ish like I forgot a comma loser

      • John


        If you READ what I wrote, you’d see that I said Apple made NFC popular, not that they were first.

        Education my troll, it helps your case when you’re smart enough to sit at the adults table AND be an adult.

      • John

        Leave the uneducated troll alone.

        You don’t need to feed it anymore.

  • KP

    Perhaps watch bands with additional sensors?

  • Andres

    At my try on appointment on Saturday I asked the sales guy what the port was for when he was changing bands for me and he said it was part of the magnet for the bands to “click”.

    I knew that wasn’t the case so I just said “okay good to know”. Then later that day I saw this post on mac rumors. Then knew what the guy told me was BS

    • John

      It could have been bullshit ooooooor it could have been what they were told to say. During my appointment over the weekend (Brisbane, Australia), they weren’t even allowed to demo the bands coming off.

      • Andres

        He wasn’t able to locate a stainless case with black rubber band in the store so he had to take it off another watch

    • Tristan

      They told me the same thing. But then I asked how come the other side doesn’t have it too? They couldn’t respond. The guy from Apple online sales who admitted he doesn’t work at that store saying it’s a diagnostic port.

  • moofer

    “…which lets your restore the device to factory settings in iTunes…”

    • Drocx

      “Though I’m just speculating here…”

  • Sun Pandey

    It’s pretty

  • iPhoneWINS

    this watch needs to be half the thickness it is now

  • iPhoneWINS

    this port is for the bands with cameras that are coming out soon…lol

  • My guess is that it has something to do with the bands. Maybe some type of patent to keep other company’s from making cheaper bands, which I hope is not the case and am stuck paying 150 bucks for a band.

  • Timothy Gray

    It’s for the 6 pound battery band that will let you get a full week of battery life.

  • tralalalalalala50

    This is great. You could imagine an LTE antenna with GPS and a large battery spread around the entire wrist to maximize reception and battery life. There is about as much volume in the wrist band as the watch itself, so this could be huge if Apple does release bands that take advantage of this soon. Heck, it could be the way to upgrade the apple watch in future generations. The band could support additional C/GPU units as well and more memory/etc.

    Fun to think about!!