What is iPhone Baseband?

Aug 9, 2010 - 64 Comments

iPhone baseband is what allows the device to connect to cellular networks

All iPhones have a baseband, and iPhone baseband is essentially the cellular modem firmware that is on your iPhone. Specifically, baseband includes the low level software that is running on the iPhones cellular modem hardware, the combination of which allows the iPhone to connect to a cellular network to send and receive data, phone calls, and transmissions.

Many iPhone owners have probably heard the the term “baseband” or perhaps read or heard about baseband upgrades. The purpose of these iPhone baseband upgrades is to improve the functionality of the cellular modem that is on the device, and the low level firmware (software) that is contained within the baseband.

iphone baseband

Additionally, baseband is also what keeps the device locked to the intended carrier, in the USA, this is commonly AT&T, Verizon, T-Mobile, Sprint, and some smaller other carriers. Buying an unlocked iPhone would not have that baseband lock, for example.

This is why when certain hardware and software iPhone unlocks are updated they are specific to different baseband versions, since modifying or ‘hacking’ the baseband is necessary to allow either a software based unlock or jailbreak on the unlocked iPhone to utilize the cellular modem on the phone, thereby allowing call, data, and SMS transfer to occur on the device. Again, buying an unlocked iPhone does not require those modifications to baseband to access other networks, which is why unlocked iPhones are generally more desirable on the resale market and for international travelers than locked iPhones, which either must be unlocked through the carrier, or through a mechanism as described a moment ago.

If you ever need to find an iPhone baseband version number, these instructions show you how to do that.


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Posted by: Manish Patel in iPhone


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  1. Abi says:

    My iPhone 6plus brought software upgrade install and I did now my phone keeps searching only connecting to WiFi, repair guy says its base band is lost, please how can u do that need my phone back.

  2. Jason Vargus says:

    Did you try putting it in DFU mode?

  3. jimmy doc says:

    i try to jailbreak my iphone with redsnow and i abort the process. now my phone is no longer detected by itunes for recovery.
    what should i do? please help

  4. kumara says:

    I have few doubts with my iphone 4s IOS 5.1.1. Can any one please clarify?

    1. Is it possible to unlock my iphone to other carriers? if yes please tell me how to do?

    2. Once the iphone is unlocked to other carrier, is it possible to lock it back to the original carrier by just factory reset.

    • Alpha says:

      1. Depends on the baseband/carrier
      2. Yes, if you restore/reset your soft unlock will be deleted and you’ll be back to the locked state.
      If you have AT&T phone you can unlock it permanently for 40$ now

  5. Sanjay Badhan says:

    hi, i just jail broke my iPhone 3g with redsnow, following your instructions. However i didn’t install the ip baseband part…My phone is working perfectly fine! Is there anything i should know or any problems will occur? I can phone and text without any problem, my cellular database is also working perfectly fine….

  6. Razor Laugh his lungs out says:

    This thread is hilarious. What a stress reliever. Good thing it got serious.

  7. norr says:

    this is my base band 04.26
    can i upgrade or jailbreak it?

  8. Hash Heesh says:

    heres my problem, i upgraded mistakenly from 4.3.3 to 4.3.5 after i lost everything i then drowngraded back to 4.3.3 unfortuately i lost my baseband and now have a itouch. Question: Is there a way to downgrade the baseband or do i need to go back to 4.3.5 to retrieve my baseband help please?

    • Jin says:

      I heard you can’t downgrade basebands period. That’s why they have different unlock for every baseband version. Try reversing it, see if it works.

  9. Jaistah says:

    @Rob’s Lawyer
    it doesn’t matter what rob meant, the fact that he gave a statement correcting an article that is irrelevant from his explanations shows how ignorant he is. The article simply provides a brief explanation on baseband updates and its purpose. A simple analogy of what you and rob did was simply sprinkled apple bits on a cake and said its an apple pie.

  10. Ray says:

    “someone got it slightly wrong”

    It depends on how one wants to approach jailbreaking and unlocking. If it’s ok to you to go through it several times before something (whatever something is) works then getting things slightly wrong is perfectly fine. For me, I prefer getting a proper jailbreak the first time and a proper unlock as well. Many, if not most, of the jail breaking advice on just about all of the jail breaking related sites is riddled with inaccuracies, omit essential information or are just plain wrong. Not to mention grammer is so awful that whatever is being said is subject to various interpretations. Ever look at the well publicized jailbreak matrix. It’s a joke and anyone going to it for advice is highly likely to be steered in the wrong direction. What’s an old version of iTunes? What’s tethered mean – appears to have many depending on the author. Are tutorials dated? No. So which is the preferred approach? I’ve done 5 iPhones so far. Using pwnage for me was such as hassle with boot loops I switched to redsnOw. Have not had an issue since. Yet the discussions are filled with people stuck in DFU mode, typically because they used pwnage. Finally, advice to those stuck in boot loops. Google and learn to use Terminal (Mac only). You will be out of your loop in a minute. Which might say something about the level of technical expertise on all of the jail breaking sites as I have yet to see that approach mentioned.

  11. Jacob says:


  12. Pat Field says:

    sad little boys feeling superior just because someone got it slightly wrong? Use the forum in the way it was intended or just keep quiet. Its stops sensible information exchange.

    • imaginarynumber says:

      Agreed. It was only neccessary for one or two posts highlighting his folly.

      BTW does anyone know if the baseband is the same thing as the radio stack in WinMo?

  13. rob's lawyer says:

    All the guys that disagree with rob are dummies, here is what he means:
    1. “Jail-breaking has nothing to do with unlocking” yes you can unlock your phone only or jailbreak it only or do both, “except that in order to install and run an unlocking program, you will have to jailbreak your phone first” he means by “unlocking program” third party software that apple doesn’t want you to use which has nothing to do with unlocking the carrier choice.
    2. “Making phone calls, doesn’t use the cellular modem, in that it doesn’t use cellular data unless you are using a VOIP client” to make phone calls you use radio receiver/transmetter the modem part decode the signal that has been received to a digital form or encode the DATA back to a signal to be sent as a signal (frequancy) for text messages internet browsing sending files..etc, voice signal doesn’t need modem.
    3. “Also, just the English problems. No hacking is necessary to allow an already unlocked phone to work…” meaning the carrier can unlock your phone for a fee no need to hack it, except AT&T is not doing it for profit purposes.

  14. FloRider says:

    How can I jailbreak my iphone 4.0.2? I have the tiny umbrella, the 4.0.1firmware and still cannot get it right. Keep getting an error code. PLEASE HELP, need important pictures restored in phone. :(

  15. yo says:

    I think this is what the first commenter was trying to get at (from redmondpie.com): “we have cooked custom PwnageTool bundles which allows you to jailbreak any device (except for iPad 2) running iOS 4.3.4, and at the same time preserve your baseband for an Ultrasn0w unlock later on.” You said “since ‘hacking’ the baseband is necessary to allow the jailbreak(sic) and unlocked iPhone” I think you meant ‘jailbroken’, since you were using it as an adjective, not a noun. The commenter was right in that you don’t need to hack the baseband to jailbreak your phone, as your rather ambiguous statement could have been interpreted that way.

    • Steeeeeevo says:

      I agree, but you know what they say though? “You can’t make an omelette without breaking a few eggs into a bowl and adding sugar, margarine, self raising flour and a teaspoon of baking soda. Mix the ingredients together trying to incorporate as much air into the mix as possible. Make sure your mix is dropping consistency, in other words, when you lift and tilt a spoonful of the mixture should naturally drop back into the bowl and not run or stay on the spoon. Add a little milk or flour if necessary now pour into a greased baking tin. Place in a 180 degrees C oven for 25 to 30 minutes. Do not open the oven until at least 20 minutes have passed (doing so will release the air). Remove from oven and place on a cooling rack. I like to decorate my omelettes with a little icing sugar and perhaps some hundreds and thousands. This is a great time to get the kids involved as they can decorate their own omelettes and feel more involved in the cooking process”. I think that’s how the saying goes.
      No, hold on, that’s just bloody cakes again isn’t it? Ignore me.

  16. mart says:

    can i unlock 4.3.2 baseband 4.10.01 or how to update the firmware?

  17. ROFL says:

    diff prson needs diff explntion..in this case, a “cakehead”

  18. […] Simples todas as versões anteriores a minha de iphone inclusive iguais a minha, mas com uma baseband (firmware do modem do celular) anterior existia um processo de desbloqueio chamado unlock que […]

  19. I'm in space! Spaace! says:

    The cake is a lie.

  20. Space cake says:

    I feel good.

  21. Laughing Too says:

    I came here just like Laughing above, looking for the meaning of ‘iphone baseband’, and ended up laughing my cakes out. Ooops! … laughing my lungs out! he he he.

  22. […] Simples todas as versões anteriores a minha de iphone inclusive iguais a minha, mas com uma baseband (firmware do modem do celular) anterior existia um processo de desbloqueio chamado unlock que é […]

  23. Jack says:

    You guys are too funny…Where did Rob disappear to ? We need you here for a bit of a ping pong match :)

  24. Laughing says:

    I came here looking for an explanation for the term “iphone Baseband”, I didn’t find it but laughed my ass off reading the comments, top stuff.

  25. jimmy says:

    No oven is required to make a chocolate baseband cake. You just mix the ingredients together and put it in the fridge. You can hack the ingredients by leaving out the eggs. Serves 8-10

    PS It goes good with a fruit drink with a tinyumbrella in it.

  26. What's a blob ? says:

    I’m a bit blobby ( probably eat too much cake!)

  27. […] The latest version of TinyUmbrella has been released and it’s compatible with iOS 4.2.1. TinyUmbrella lets you save SHSH blobs from compatible hardware, allowing you to upgrade your iOS version while maintaining older versions of baseband. […]

  28. FISH5742 says:

    I like sprinkles on my cake.

  29. Rob you suck says:


    Rob.. Do you enjoy being a dick for the whole world to see??

    Yes, my iPhone is unlocked and I didn’t need to hack it! I live in a country where the US pricing/tethered to AT&t model is not allowed under our laws.. Ie no monopolies, therefore no locked phones.

    Also, get with the times too re modems and cellular data etc.. They’re the same!!

    You seriously need to get out more.. Find a girl or something??

    • ^ well said says:

      Rob.. Do you enjoy being a dick for the whole world to see??

      HA I am still laughing at this….Rob’s a deuche

  30. Rich says:

    The comments here are funny, when I got my iPhone 4, Apple didn’t tell me that it’s telepathic, my iPhone calls for a cake every morning, it even know my fav cake is chocolate cake!!!!

  31. Diztract says:

    I like Red Velvet cupcakes. Smilen=)

  32. […] carrier than what it was intended to be used for. Note that unlocks are often dependent on your iPhone baseband, baseband is really just another name for the devices cellular communication transmitter, or […]

  33. […] versions and feature that were released with them and which iPhones those feature were applied to. Here is a short article about what basebands are. You only need to worry about your baseband IF you want […]

  34. Olystretch says:

    I like cake.

  35. rob says:

    Wow, sadly it’s not surprising to see so many technical inaccuracies in articles like this, but…

    1. Jail-breaking has nothing to do with unlocking, except that in order to install and run an unlocking program, you will have to jailbreak your phone first.
    2. Making phone calls, doesn’t use the “cellular modem”, in that it doesn’t use cellular data unless you are using a VOIP client.
    3. Also, just the English problems. No hacking is necessary to allow an already unlocked phone to work…

    • QU says:

      1. If you have to perform one task before another, it’s related. That’s like saying baking a cake has nothing to do with an oven, except that to get the cake to actually cook you need to put it in the oven.

      2. I don’t know how else you’d make a phone call or use cellular data without baseband (or as the article simplifies, modem), that is how it transmits data. Is your iPhone telepathic?

      3. “No hacking is necessary to allow an already unlocked phone to work” – much like how you don’t need to bake a cake again after it’s already baked, it just needs to be baked the first time, right?

    • Manish says:

      What exactly is technically inaccurate? Perhaps you do not understand the concepts. I am not really sure where to begin as your comments suggest you didn’t even read the article. You must jailbreak to unlock an iPhone, there is a clear relationship between the two. How else would you transmit data on an unofficial carrier without an unlock? This ‘hack’ targets the baseband.

      If you feel you have a better layman explanation of anything, feel free to comment or email us: osxdailycom@gmail.com

      – Manish

      • Jheremy says:

        Hi there…to make it simple,jailbreaking an Iphone is basically allowing users to access third-party softwares and applications that you can’t install on an official Apple firmware.This is due to Apple’s limitations and policies.Unlocking is basically freeing your Iphone from an specific carrier (AT&T or T-Mobile) and unlocking your Iphone means that you can use it to any carrier.Baseband is a software that drives your Iphone signal,including GSM,EDGE and Wifi connections.That’s it.

    • Mike says:

      The other guys are true, your making yourself look like a douche.

      Me, I have been jailbreaking and unlocking iphones, and iPads, and jailbreaking iPods. One thing for sure, in order to unlock a damn iPhone, you need to jailbreak it so you have the ability to unlock. It’s true that you don’t need to hack the iPhone to unlock it if it is already unlocked by manufacturer.

      iPhones work the same way as regular cell phones. Just that they have way better features and such. Cell phones communicate with phone towers to make phone calls. The baseband that is used for those towers will allow the cell phone make a call. It’s the same way with iPhones. You don’t need internet to talk to someone, as long as you have connection with a phone tower, you can communicate with someone else with it. VoIP has nothing to do with anything, unless your using an app that uses phone features to contact people.

      Just a little side note, do a lot of research before blurting your mouth on a site about unlocking an iphone. Lots of people will laugh at you because of it and you make yourself look like a fool. Thanks.

      • futurepr00f says:

        Gevey sim? that requires no jailbreak to unlock….

      • sele says:

        hi I need help to jailbrake my iphone i have tried all the ways to downgrade the IOS but it looks imposible i also bought a program to jailbreak but it does not work with IOS 6.1.2 what can i do

  36. […] you need to know what version of iPhone baseband and firmware your device is running, you can find the information directly on your […]

    • Lacy says:

      So, this is what I understand:

      If your phone is not already unlocked, which it probably isn’t if you didn’t buy it directly from Apple, this is what you have to do:

      1. In order to unlock your phone, you need to jail break it.

      2. You can jail break your phone with the simple program “Jailbreakme”

      3. After you jailbreak, go to the App Cydia (which downloads after you use “Jailbreakme”) and download “Ultrasn0w” – an app that unlocks your phone from its carrier

      a) Ultrasn0w will only work on phones that have certain basebands
      (ex. iPhone 4 baseband 01.59.00; and iPhone 3GS basebands 04.26.08, 05.11.07, 05.12.01, 05.13.04 and 06.15.00.)

      b) If your baseband isn’t one of these ones listed, you are out of luck my friend. You will not be able to unlock your phone, but you will be able to jailbreak it! Which is great if you want cool new apps and etc. Not great if you want to travel.

      c) unlocking your phone allows you to travel internationally, buy a SIM card from any country, pop it in your phone, and ‘voi-la!’ you have access to their 3g network!

      d) you don’t need to unlock your phone if you just change your existing package to accommodate travelling; however, it’s much cheaper to simply switch carriers as you travel and live abroad.


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