Do I Have an iPhone 4 or 4s and How to Tell the Difference

Do I Have an iPhone 4 or 4s and How to Tell the Difference

This week, we bring to you the answer for a common question that we get from customers who are looking to buy a Phone Doctors DIY screen  Replacement Kit for iPhone 4S or the iPhone 4. Shopping for replacement parts for any device can sometimes be tedious, especially if you have multiple revisions of what appears to be the same phone parts. This article is designed to help you decide to speed up the process of fixing your device.Here are a few ways that you can tell the difference, so that you can order the correct parts for your iPhone 4 GSM, iPhone 4 CDMA or iPhone 4S. First, it’s important that we answer another question. Simply because you need to know the difference if you have an iPhone 4.

What is GSM and what is CDMA?

GSM phones are the most common band of phones in the United States and throughout the world.  In the United States, the largest GSM phone carrier is AT&T.  In Canada, the largest GSM phone carrier is Rogers.   This is important because the parts for GSM phones typically do not work with CDMA phones.

CDMA phones are common in the United States with Verizon and Sprint.  These phones often look a lot like GSM phones, but they are on a different spectrum of carrier waves than GSM phones.

Just to make things a little more confusing.

The iPhone 4S works with both GSM and CDMA carriers. That’s right. The iPhone 4S works with AT&T, Verizon, and Sprint, to name a few.  The hardware is designed to work for both GSM and CDMA, and the software that comes with the phone is what determines how it connects.  The great part about this is that if you have an iPhone 4S, then you simply need any part that is designated as an iPhone 4S part. Just to be clear, iPhone 4 parts almost always do not work with an iPhone 4S, and the parts for an iPhone 4S typically do not work for an iPhone 4.

iPhone 4 GSM

The first phone we will be looking at is the iPhone 4 GSM, which was originally built for use on AT&T/Rogers networks. A GSM phone requires a small chip called a SIM card in order to receive service. This SIM card usually goes in a special compartment on the side or top of your phone. In the case of the iPhone 4, the SIM tray is found on the right side and can be opened with a paper clip or SIM tray opening pick. The bracket configuration on an iPhone 4 GSM screen contains a space for the SIM tray, but also has an off-set corner bracket on the top of the phone by the headset jack. In addition, the iPhone 4 GSM does not have SIRI voice commands.


Look on the metal mid-frame. Is there a black line above the volume & mute buttons? Now, is there a SIM card tray on the right side of the mid-frame? These are the things to look for.



The iPhone 4 GSM will always have a SIM card tray.  The SIM card tray is located on the right side of the mid-frame, and yes, there is a black line near the bottom, but it’s like that on all of the iPhones.


iPhone 4 CDMA

Next, we have the iPhone 4 CDMA, which was built for Verizon and Sprint networks. Sometimes, you will also find this device on Cricket and other small CDMA carriers. The big difference between this one and other iPhone models is that this one does NOT have a SIM tray door. In addition, the bracket configuration on the screen will have a bracket blocking the spot on the right side of the screen where you would normally find a SIM card tray. Although the iPhone 4S shares the same REAR trim/door as the iPhone 4 CDMA, the front trim (which is attached to the LCD/Digitizer assembly) is different.

You will notice on this model there are 2 black lines located at the top of the mid frame on both the left and right side.



The iPhone 4 CDMA model will not have a sim card tray on the right side of the mid-frame.



iPhone 4S

Finally, we have the amazing SIRI-Enabled iPhone 4S. Unlike it’s predecessors, the iPhone 4S is cross-carrier compatible, which means it only has one set of hardware regardless of the band it is programmed for. One of the most common mistakes made when identifying an iPhone 4S is the SIM tray, which sometimes gets misidentified as an iPhone 4 GSM phone. Unfortunately, the iPhone 4S trim bracket configuration will not fit an iPhone 4 GSM, so again it is important to identify your device prior to picking out your replacement parts. Here is a picture of the iPhone 4S and what to look for when verifying the model.

You will notice on this model there are 2 black lines located at the top of the mid frame on both the left and right side.  The iPhone 4S will also include a SIM card tray.



Another quick way to tell if you have an iPhone 4S is to see if you have SIRI on your phone. To check for Siri, hold down the Home button on your iPhone 4S. You’ll hear two quick beeps and see “What can I help you with?” on the screen.



Well that’s it for this week. By now you should have a good idea on how to tell the difference between an iPhone 4 GSM, an iPhone 4 CDMA, and an iPhone 4S.

Need some help, or have some info that we missed? We would love to hear from you. Simply add your comments on this blog, and if needed, someone will get back with you in 24 hours.

Have Questions? We Have Answers Here!


  1. I thought I was buying an iPhone 4S and turns out its a iPhone 4 CDMA . What can I do to get an iPhone 4S gsm unlocked ?

    1. Hello Ashely,

      sorry to hear about that iPhone 4s. Unlocking a phone cdma for gsm is possible, sometimes depending on the carrier. My recommendation is to contact the original carrier to see if they offer unlocking, for that device.

      Best of luck
      Robin B.

  2. is it safe to put os9.1.2 on a 4s or might i regret it?

    1. Hello Steve and thanks for your question.

      As of right now, the most up to date version of iOS for the iPhone 4s is iOS 9.2.1. I personally used an iPhone 4s until just a few months ago. It ran fine from iOS 5 all the way through iOS 8. But once I put iOS 9 on it, it ran noticeably slower and I also started experiencing issues with sliding to answer phone calls and pressing buttons like "End Call" or "Mute".

      I personally do not recommend the update but, if you need to install an application which requires iOS 9.2.1 then I would go ahead and update.

      I hope my comments have been helpful.

      Thank you,
      Matthew Jones.

  3. I have a iPhone 4 CDMA and try to update it but it says the latest update is the iOS 7.1.2 what do I do?

    1. Hello Ryan and thank you for the question.

      I'm not sure if you are aware but the highest version of iOS that is allowed by Apple to be installed to an iPhone 4 is iOS 7. (It was not allowed to move forward to iOS 8 or iOS 9.) If you are attempting to reset the phone, choose the "Restore" option and reinstall iOS 7.1.2 onto that device. It doesn't go any higher for that device. :'(

      I hope my comment has answered your question.

      Thank you,
      Matthew Jones.

    2. What do i do

    3. How many iphone 4's are there

  4. when i hold down the home button it says voice controll is this siri or do i have just a iphone 4

  5. Hello i have question on iphone 4 how i could update it from ios7.1.2 to another level beyond it. Realy i didn't know how to determines iphone gsm & iphone cdma clearifying me well and which is more suitable between them

  6. Sir, I have iPhone 4s mobile, is this mobile will support iOS 9?....reply me sir

  7. how can i nstall some application on iphone4 if it requires ios 8 or 9?

  8. My phone drop accidently the screen went blank,then came some red and blue and white lines running top to bottom of the screen

  9. My iPhone 4S charge is only for a few hours, and I feel it is warm, what can be the problem

  10. Hello how can I unlock an iPhone 4GSM
    And is it possible to install whatsapp on iPhone 4GSM ?