Any Nexus or Google Play Edition device owner has seen it at least once. You get an OTA update to a new version of Android, and you notice that it says "Via Wi-Fi only until" and some arbitrary date. There seems to be a lot of confusion with people regarding what this is and more importantly what it is not. We feel like it's time to shed some light.

A lot of times, when there's a new Android OTA update available, this date becomes annoying to people because it means they can't download their OTA over a mobile network. Even in this day and age, not everyone has ready access to WiFi at the drop of a hat. As annoying as that can be, there's another problem with the date. After an OTA rolls out and weeks pass, the buzz dies down. Randomly, someone will have to wipe their device's data and flash back to stock, or get a new device. They'll get the latest OTA update, notice the "via WiFi-only" date and start to apply a thought process that goes something like this:

  • All the old OTA updates are available via mobile.
  • That must mean this OTA will also become old on that date.
  • That means Google is going to release a new Android version starting on that date!

While that may seem ludicrous to some, there is definitely logic behind it. Anyone who cruises sites like XDA or RootzWiki with any regularity has almost undoubtedly run into posts like this. That's not what that date is for, though. There is simply no correlation between the date and when Google chooses to release new versions of Android. These WiFi-only dates come and go all the time without there being updates to go along with them. As with most things Google does, there's always a rhyme and reason to why one of its products does what it does, in the way it does it. With that said, searching for Android release timeframes by looking at OTA WiFi-only dates is, frankly, a fool's errand.

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So now that we've explained what the WiFi-only date is not, it's time to venture a guess at what its actual purpose is. The date is mysterious, and there is a lot we don't know. That said, let's start with what we do know.

  • If there's a WiFi-only date at all (which is not a given), it seems to only be applied to the most recent update for a given device. Older updates can almost always be downloaded over mobile data. That's not to say this is the case 100% of the time, but historically that has generally been how it goes. 
  • The date you see is not set in stone. The date can be, and often is, extended for no apparent reason.
  • Sometimes the date will be set out for several days or a week from the present day, other times it's perpetually set to the next day's date. There's no pattern to it.

As for why Google would restrict OTA updates to downloading over WiFi in the first place, that's anyone's guess. Google does not make the full OTA system available via AOSP, so we can't dig through the code to find the answer. If I had to theorize, I'd say that it has everything to do with people not being forced to use their mobile data to download a huge OTA update. Remember, in stock Android, updates download in the background with absolutely no input from the user at all. The only choice you're given is whether or not to install the update, and you are only given that choice after it's downloaded. It seems logical, then, to provide people ample opportunity to connect the device to WiFi before force-downloading an update. When you consider that many people have data plans of 2 GB or less, downloading a 200 MB system update could cost you 10% or more of your bandwidth for the month. That can be a pretty steep price to pay for a download that you had no ability to cancel or defer.

Whether or not my theory stands up to scrutiny, one thing is certain. The WiFi-only date has absolutely nothing to do with when we're going to see a new update for any device. If there's anything that Google has taught us in Android's first 5 years, it's that it will never give an inch when it comes to telling us dates for new versions of Android. That has been an iron-clad policy of Google's from day one and there's absolutely no indication of it changing in the foreseeable future.

Shawn De Cesari
Shawn is a web developer by day and XDA's resident archivist for Nexus and Google Play Edition device OTA updates by night. When not immersing himself in code or Android, he can be found hunting down antique signs, taking road trips, listening to music, or playing video games. His daily drivers are a Nexus 6 and an iPhone 6 Plus.
  • mgamerz

    I don't see how anyone would mistake wifi only to mean anything beyond 'i can only download it via wifi right now'.

    • REN3GADE

      You've never worked customer service have you?

    • http://randomphantasmagoria.com/ Shawn

      You'd be amazed at how often we get tipped here that the new Android version is coming on some date, and they base it on that WiFi-only date.

      • Simon Belmont

        Oh, man! I've seen this happen before.

        I've seen scads (YES, SCADS) of xda threads with people thinking that date meant something. Yikes!

  • Karlo

    For people that cant wait for new Android OS version.
    Flash factory image via fastboot.
    fastboot flash-all.bin

    • blahmoomoo

      Or sideload the appropriate OTA with adb in stock recovery, as instructed in every new OTA post here on AP. Assuming you haven't modified any system stuff, of course.

    • Nabendu

      that is fastboot flash-all.bat and not .bin

      • Karlo

        .bin or .bat whatever

        • gettingredder

          yeah... .bin or .bat or .cluess or .idiot whatever works

    • Tarun Pemmaraju

      It's just flash-all.bat, since that invokes fastboot by itself.

  • glennv17

    I originally upgraded my Galaxy Nexus (those were the days) to 4.3 because it was using data to download the update even though I was on AOKP's 4.2.2 ROM. Only way to stop it was to block background data, but that meant any other sync was ruined. As it was, I'd already blown my cap and had to pay excess charges. Frustrating as hell.

    • Simon Belmont

      That's odd. My G'Nex showed the Android 4.3 update waiting to download, but it wouldn't do it unless I turned on Wi-Fi.

      I forgot about it, and about a week later it downloaded it over my mobile data automatically. Thankfully, I have unlimited data.

      • blahmoomoo

        I'm assuming they didn't want the OTA, but were forced to take it because it kept on downloading on mobile data after the WiFi-only date.

    • SorinDobrin

      I had the same issue with Gnex and Aokp , it would download the Ota over and over , with root you can disable the update service completely.

  • Peter

    you can wind the clock forward on the device and bypass the wifi-only restriction if ever you need to. google ota system seems to use he devices date rather than the servers date.

    • http://randomphantasmagoria.com/ Shawn

      Good tip!

  • John Smith

    I don't ever recall seeing that message on my Sprint phones before. I'd wager to guess that the message is all about bandwidth management

  • Rob Cook

    You can get, and I have been, refunded for OTA's being downloaded via cellular data. I had just reflashed to stock, hadn't had a chance to reattach to my wifi and a large OTA update came in via cell data. I called AT&T explained the situation and was credited on my account that month.

    • http://twitter.com/anishbhalerao Anish Bhalerao

      Wow. AT&T did that?
      AT&T? :O

    • NemaCystX

      I'm sure if you told them the WHOLE story they wouldn't have done it. Flashing is against their policy so it wouldn't have held up as a legitimate excuse to get a credit for your data. It was your own fault because you were on unauthorized software but wanted to get the latest OTA. Thats whats wrong with this world, deceit and thats also stealing If it had been me I would have eaten the cost and if I were AT&T I would have said "Tough kitten caboodle's"

      Its liars and deceitful people like you that make it tougher on us legitimate customers. It makes prices go up when the company has a loss they have to eat.

      This kind of bullshit makes me frustrated

      • vibey101

        I don't see what the problem is. Whether he was stock or on a custom ROM either way he still would've used his cellular data for the OTA download. The fact that they make you use your own data to download OTAs is wrong. And the way you're defending AT&T makes it seem like you think they are an honest company. Relax you really made a big deal out of nothing.

      • Randroid

        What if he had to reset to factory defaults for some other reason? Would it still make you frustrated? Probably not. This is not stealing, it's simply using the device to its full extent, which is limited by the carriers stupid data limit.

  • Simon Belmont

    Haha. People think the OTA expires after that date? It's bits and bytes, folks, not a piece of fruit from the manager's special tray. I didn't know that people actually thought that, though.

    When I first encountered it on my Galaxy Nexus for the Android 4.3 update, I just assumed it meant that until that date, I'd have to switch on Wi-Fi to grab the OTA. I actually forgot I had the OTA waiting to download, and a week or so later, I noticed one morning that it had downloaded over mobile data (no biggie, I have unlimited), so I guess that proved my theory. Nice write-up, guys. I love how you guys analyze even the most minute details of every aspect of Android.

    • http://www.androidpolice.com/ Artem Russakovskii

      No, they just think that particular update gets replaced with a newer one, and that must mean a new version of Android.

      • Simon Belmont

        Ah. I see now.

        I've actually had a couple people ask me, IRL, if that was an expiration date, though. I'm glad that's not what MOST of the people are asking because that would be pretty sad.

    • stevee

      I thought it meant I would be offered the new version of Android up to that date, but only over wi-fi. But if I hadn't connected to wi-fi and got the update by then then I'd stop being offered the update and I'd go back in the randomized pool until my number came up again.

      *shrug* The article taught me something I didn't know and now I'm happier. Thanks, AP!

      • Simon Belmont

        It taught me that lots of people interpret fairly vague wording in wildly different ways. Haha.

        It was a good write-up, though. PSAs are almost always good when coming from AP.

  • Eric Jones

    Does the option under Settings > Data Usage to "set mobile data limit" have any effect on the date? I'd imagine that if you had a limit on your data that expired soon, it might wait until that date.

    • Simon Belmont

      It'd be nice if it was that intuitive. I don't think it is, though, sadly.

      My data "expires" on the 2nd of every month. The Wi-Fi date in the OTA is set to tomorrow, though, so it doesn't seem to care when my data "expires" at all.

      • john

        Move your date forward in system settings.. it'll then allow you to download over mobile.

        • Simon Belmont

          Oh, yeah. I knew you could do that.

          I was just replying to the above poster about whether or not it was true if your data usage was tied to allowance of downloading the OTA over mobile data. It's decidedly not.

      • Eric Jones

        Well that was my only guess. My update came through when I was on wifi already. I didn't even notice it until it was already downloaded, so I had no way to test.

        • Simon Belmont

          Yeah. I wasn't criticizing or anything, because your guess was actually a smart idea.

          I wish it actually worked that way. The Android 4.4.2 update for my Nexus 5 actually just "expired" on Wi-Fi and downloaded via mobile data. *Shrugs at 55 MB of unlimited data used.* Haha.

  • https://play.google.com/store/apps/developer?id=iWizard Bikram Agarwal

    I would guess that that "wifi only until..." is there for new updates so that massive number of users don't clog the network while downloading it all at the same time. Google wants them to use wifi to download it and when a large of users are done, the excitement has died down, then rest of the users can download via mobile data; thus a smaller hit on the network.

    • SeBsZ

      This is what I thought exactly

    • Freak4Dell

      I think this is why. It perfectly explains why it's only applied to new updates and not to old ones.

    • karlvanh

      Agreed, you gotta love Google for this :)

    • http://randomphantasmagoria.com/ Shawn De Cesari

      That's an interesting theory. I didn't think of it from that angle. I like it!

    • Randroid

      I was thinking the same thing while reading this article. It's similar to why they roll out updates in phases. Wi-fi, in most cases, makes it so that the download happens quicker, therefore clogging up the network for less time.

  • cc_star

    My mobile network (Three UK) has unlimited HSPA+42 (upgrading to 4G in 2014) for just £15/m. This runs over 5 times faster than my home broadband.

    Anything which forces WiFi-only is a huge, inconvenience. I can understand why Google doesn't force updates over mobile, but there should be the option (along with the Play Store-style data cap warning) for people who do everything over mobile.

    • Daniel Smith

      Exactly. I never use Wi-Fi on my phone.

  • Cheers

    This Wi-Fi only to protect mobile data seems dumb, and I'm surprised no one pointed out the setting to Auto-Update apps in Wi-Fi only. Logically, this should extend to OS updates. If I dont want an app update (which is just a few MB), why would I want a 200MB system update?

    If people need it spelled out, then add an extra option in settings.

  • Robin

    I only have 200MB per month, how can I prevent automatic downloading after this timeframe? It's ridiculous that it starts downloading automatically. Some people even have to pay a lot after reaching their limit, this could mean they'll have to pay hundreds of dollars for an OTA they did not start own their own.

  • llf

    When I see that, I will probably ask my friend by my side to turn on his portable hotspot. And vice versa.

  • john

    You can just change the date forward in system settings and it'll then allow through mobile. That's what I've always done.

  • Daniel Smith

    I dislike the way this works considering the OTA will download faster over the mobile network than Wi-FI for me and I have no data cap.

    • http://randomphantasmagoria.com/ Shawn

      You're very much in the minority.

      • Roh_Mish

        Maybe in US. But outside, unlimited 3G data is not rarity.

  • LosAngelesBen

    It simply means that the current update is guaranteed available to be pulled onto your device before that time. They send updates in waves and your device is the next wave when your update appears. It moves on after that time frame unless they change it from above.

  • XCMeathead

    Isn't it just so they don't end up with 1000s of people downloading the same 200MB update over their wireless network at the same time, which would screw the network up for other people?

  • Roh_Mish

    Google has some agreements with the US carriers to keep the large OTA away from their network and we people from outside U.S.A. have to suffer due to them.

  • Captain Obvious

    Come on, this is OBVIOUSLY to protect the networks from crashing due to 100000s of people downloading OTAs at the same time...