CM12.1 ROM for Galaxy S3! [Android 5.1.1][Official]


For those of you who have been waiting for official CM12.1 with latest Android 5.1.1, we have some good news for you as official CM12.1 ROMs are finally here!

These are based on latest CyanogenMod sources with latest Android 5.1.1, meaning you will get all of the new Android 5.1.1 features including soft buttons with hardware keys disabled.

Best of all, these builds have everything working out of the box including camera and Netflix. I know many of you with Sprint S3 were having trouble but these CM12.1 have flawless camera for all S3 models. (official builds are available for all S3 models except GT-i9300)  Performance is excellent along with great battery life on these builds.

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62 Responses

  1. Erik says:

    I’m coming from the unofficial CM 12.1 5.1 , running the att version on my T-Mobile t999 . could I just flash this T-Mobile one over it , or would I have to keep putting att versions of it over ?

    • Dale T says:

      I was in the same situation, Erik, having flashed the CM12.1 tagged UNOFFICIAL which then registered my T999 as an i747 phone. But I downloaded the T-Mobile zip file (linked above) and was able to do a dirty flash (using the same GAPPS zip file I used previously) and the phone appears to be working great. It is now registered internally as a T999 phone. My Camera app (Cyanogenmod?) now works and another error I had with voice searching seem to be corrected. With the dirty flash, I was able to retain my phone’s setup as it was before updating. So yes, I think you should be able to do the same.

  2. Will says:

    Will there be an official ROM for the i9300 at some point? Please say yes.

  3. Luis says:

    I’ve been trying several ROMs from every Versions on my i9300 with no success… I mean, after a few days my device become almost impossible to use due slowness. I’m now using a ROM said to be the most stable and fast (Revolution HD 5.3). It was doing well until now. I’ve tried all 12 CM versions with the same problem. Does anyone have any suggestion ? I’ll try this ROM as well, but I don’t see much hope. Another question I’ve got is regarding internal storage… How could (if should) I clean this ? I have my photos saved in the cloud once my internal storage is quite low. Thanks mates.

  4. Forge says:

    I am interested to see if 5.1.1 has improvements over 5.1. I just restored my backup to stock because I had issues in several areas with 5.1. Bluetooth with any MP3 music app had issues while Bluetooth with slacker radio worked fine. GPS had poor performance and most apps took 5 minutes to get a signal. I also lost wifi calling for T-Mobile which may not be a consideration for developers as most carriers don’t use it (not sure on that one). Otherwise, I liked the new OS. Unfortunately, the issues I had became a nuisance. I also noticed the 5.1.1 comes with separate ROMS for T-mobile and ATT when before it was bundled in one and turned my phone into an ATT phone and different model. Perhaps what caused all my issues. Wondering if anyone had any similar situations. Thoughts?

    • Jeff "Ryder" Whitsett says:

      It returned mine to stock until I enabled the root again and it works like a charm. Go to your developer settings to restore your superuser functions. Hope this helps you.


    i keep getting optimizing app screen then the phone reboots. im on att, please help me max

  6. Jeff "Ryder" Whitsett says:

    The camera works, the battery life is good, it makes my T-999 smoother than the Kit Kat Carbon room I was running previously! Thanks Max for the links and the heads up. You Rock!

  7. navpal says:

    where is this official build found on? I tried to find it on but couldn’t find this release

  8. Dylan says:

    The only problem i have at all on this rom is the app drawer lags. I’m hoping for this to be fixed in a future version. Running on Sprint Galaxy S3
    Thanks alot for all the effort you put in all your sites Max!

    • Dylan says:

      I’d also like to add that the app drawer lag can be fixed by installing an alternative launcher. There are lollipop launchers that blend right in with the rom well

  9. adrian says:

    Everything works . I’m on t999.
    Only issue no DATA! Anyone having this issue ?any help would be great!

    • J says:

      I installed on an AT&T device and had the same problem. Tried flashing several times with no change. I have flashed my phone over 100 times and there was quirks in a lot of them but this is the biggest deal breaker of all of them. Not sure what the problem is. I know there are no APN’s for some reason. Not sure how to get them back, so, some advice woukd be appreciated.

      • adrian says:

        no luck anyone?? really want to run this rom!!!

        • KengVang25 says:

          I have successfully installed this rom with Data , strangely though it pops up 3g even though I have 4g . ahaha .

          What I did I had to revert back to stock rom 4.3, keep in mind I have the T-mobile version. Once you’re back to stock rom update to the latest firmware. Root your phone again . Follow the tutorial on how to do so if necessary . Then install the Custom rom following the instructions . It should give you data now . Well it did for me anyway . G’luck . If it works pass on the words and help others . Got it working today . 🙂

      • Llourd Zakus says:

        Am having the same on at&t and everything seems to work alright except my internet data…Any solution yet??

    • Sam says:

      I’m having the same problem. No data! Did anyone find a fix?

    • kevel says:

      Anyone find a fix for this yet?

      • Sam says:

        All I needed to do was go into the settings/mobile networks/access point names. Then select the proper network. My data was back just like that!

    • KengVang25 says:

      I have successfully installed this rom with Data , strangely though it pops up 3g even though I have 4g . ahaha .

      What I did I had to revert back to stock rom 4.3, keep in mind I have the T-mobile version. Once you’re back to stock rom update to the latest firmware. Root your phone again . Follow the tutorial on how to do so if necessary . Then install the Custom rom following the instructions . It should give you data now . Well it did for me anyway . G’luck . If it works pass on the words and help others . Got it working today . 🙂

    • Cody Carter says:

      Yes I have that problem too and signal just cuts out when I know I should have it

  10. Android user says:

    Default camera still not working on mine SGT-T999 it says” Can’t connect.
    Open Camera works well.
    Other than that no issues at all.

  11. David Taylor says:

    Hey I downloaded the thing for AT&T SGH-i747 and I wiped all my stuff and when I went to flash it, I got this thing saying Status 7 & error and it aborted the flash saying that my phone is d2mtr and the build is d2att, so i dont know what to do….

  12. joe says:

    max will there be a GT-i9300 CM 12 (5.1.1) ?

  13. BenjamĂ­n Santiago says:

    I Flash CM12.1 On My S3 From AT&T And The Only Problem Is The Internet Connection (No Working)

  14. Jake G says:

    I flashed cm12.1 to my sprint s3 from wicked x 8.2 because i wanted the lollipop goodness and it was almost everything i wanted! the only problem ive run into is that my 3g and 4g lte dont work at all! i checked the apn and everything showed not set so i tried multiple apn settings i found on line but it wont save them. on occasion a list of apns would appear in my list but none worked. I downloaded the rom on my laptop 2 different times and again on my desk top hoping i might have got a corrupted file but nothing worked! still no data. any ideas?
    thanks for this site man!

  15. Jose Torres says:

    I flashed this rom for my sgh-i747 using twrp recovery and flashing the rom, gapps and the, and everything run out off the box flawlessly even the google camera app run well, I see peoples having problem with this rom my advise is make sure to flash supersu or will have root problem on everything, this was same for me before flash the believe me it save your lot of headache.

  16. Jose says:

    I have a t999v and I’ve stalled this ROM but my flashlight doesn’t work anymore. The app that comes with cm12 and another one that I’ve downloaded on play store didn’t worked. Any solutions?

  17. Aram says:

    File manager not working or not opnening !!
    plz help

  18. upatedmike says:

    I have trouble with all the Lollipop roms working with my Gear Manager (Galaxy Gear S). It recognizes the phone in bluetooth but the software hasn’t ever worked. Any thoughts?

  19. Dylan Douglas says:

    I have installed this on my Verizon galaxy s3 with an unlocked bootloader. The only problem I have is that the app drawer has extreme lags which I cannot stand. Has anyone found a fix for this. BTW I have tried many of the nightly releases to cm 12.1

  20. Lee Barcenilla says:

    Is anyone having problems with the GPS? Is their a fix or patch? Please help

  21. Dick Clase says:

    I have a Sprint SPH-L710. Installed the android 5.1.1. Liked it but had trouble with the bluetooth. Won’t find devices or would connect for awhile and the drop the connection. I use bluetooth all the time with my Zenwatch and bluetooth speakers. I gave up and went back to android 4.4.4.

    • Android says:

      Hey, how did you install ur custom rom on ur Sprint s3? I’m about to do it but im scared i’ll end up in a bootloop.

      Which Bootloader(nj2,nd8,mk3,etc) were u on and how did u flash CWM or TWRP? (Via odin, flashify, twrp manager, etc)

      • Dick Clase says:

        Just check out this website. All the info you need is here. Just make sure the rom you download is for your model phone. For example mine is SPH-L710.

  22. Bogdan says:

    Hey , so I instaled the unofficial ROM for my GT-I9300 , works good but I have 1 problem , when I go to settings<mobile network I get the error and I cant acces the seting , eny solution ??

  23. nomi says:

    hi friends.
    i have upgraded my samsung s3 sgh t999 to sgh i747 lollipop5.1 but i have some problems with it .all thing work well but when i open the supersu it says that continue installing su binaries . i hit continue but it fails . how can i install su binaries on 5.1 help please…

  24. Jon says:

    I’m trying to use my phone but I cannot use my data. It doesn’t show any signal, yet I can make calls but cannot access the internet or anything that uses internet. Help?

  25. Tech-Shaman says:

    I Love the 5.1 on my Rogers SGH-i747 its fast feature rich but. Unfortunately 3 deal breakers. 1-Excessive heat and power drain lasts less than 2 hours (that’s just sitting there) I tried turning off wifi/lte no difference. Ran an app monitor that shows nothing out of the ordinary. I have gone back to stock, rooted and tried again (no additional apps) same issues. 2- LTE speed switches to H* 3G 4g then LTE . network speed test monitoring reveals that it is in fact fluctuating. With stock rom in same location LTE 100% no changes. 3- Camera only works 1 time after I re-boot. cant use 3rd party software for bank deposits or scan software.
    This is all really too bad as I really like 5.1 ……Back to 4.4.3

    • Edgar says:

      Did you have STOCK 4.4.3 before installing the CM 12.1 rom?? I want to know if the bootloader is locked with stock. I have stock 4.4.2 on a Canadian (Telus) i747m and it seems no one knows whether or not the bootloader is locked on the Canadian i747m with STOCK 4.4.2, so was yours STOCK android?

  26. jim says:

    not even booting most of the time and and reboots out of recovery when I try to use it. I’ve got a sprint sphl710 that was rooted with towel root while running ND8 4.4.2 the last ota update I recieved and cwm installed with ROM manager and then xposed framework. Then I flashed cm12 but didnt like it.Then wiped and flashed cm11m12 snapshot and the camera didn’t work. Then wiped and flashed cm12.1 nightlies and have been doing so for a few weeks. one of the last nightly updates has it bootlooping and trying to optimize apps every time. once in a while it will completely boot so I used flashify to install tarp and I’m getting the same problem I’ve had with cwm since this all started. if I boot into recovery it will freeze and reboot the phone when I start to do something. I can start to flash a new update but it will freeze during the process and reboot with the new update as if it flashed. And factory reset/wipe cache/dalvik all apparently do nothing. when the bootloop problem first started I did factory reset, wipe cache and wipe dalvik and that worked removing the os completely. if I turned off and back on, it would boot into recovery. now neither cwm nor twrp will stay booted and work. Could the problem be the bootloader, recoveries (tried the latest cwm then tarp) or is it cm12.1?

  27. Elias says:

    Does this works in oficial 4.3 UCUEMJB AT&T?

  28. Edgar says:

    Anyone try this successfully with a Canadian i747m that was on stock 4.4.2? I wanna try it but don’t know if it can work, as I’ve heard the bootloader might be locked with stock 4.4.2 on the Canadian GS3′s. Anyone?

    • bill says:

      I did it today with 4.4.2 stock 1747M Galaxy S3 (Bell): for the ROM and

      All works great (so far) except the camera.

  29. Alison says:

    After installing this rom my T-Mobile S3’s camera is not working. When I open the camera app it says camera cannot open.

  30. Cody Carter says:

    I installed this but there’s no Google apps. How do I get the Google apps such as the play store on this ROM (5.1.1) if you could help that would be amazing thanks.

  31. William says:

    Netflix is still not working on cm12.1.

  32. Kevin says:

    I have SGH t999 and I flashed this rom with the latest CWM recovery but I am not getting any sound…no system sounds no music etc…can anyone help?

  33. Anel says:

    I was able to downgrade from 5.1.1 to 4.4.2

  34. Dave George says:


    We are a CDMA – LTE carrier that relies on Verizon devices. I need to disable IMS and vzwims apn for LTE to work on our network. Can you help us with a custom ROM.


  35. himanshu Vishwakarma says:

    Hey I also want an afficial cm12.1 for s3 i9300

  36. himanshu Vishwakarma says:

    Hey I also want an official cm12.1 for s3 i9300

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