OnePlus starts rolling out OxygenOS 3.5.3 update for OnePlus 3T and now the officially released update is available for OnePlus 3T. This firmware is based on Android 6.0.1 Marshmallow. OnePlus always stands top regarding releasing updates and it is expected that we'll soon get the Nougat update for OnePlus 3T, but until then download Oxygen OS 3.5.3 official update for OnePlus 3T. The latest update rolling out via OTA (over-the-air). Thus not all users can get the OxygenOS 3.5.3 at the same time. If you do not want to wait for the update reach in your region, then you can install it manually by following this step by step guide. Oxygen OS 3.5.3 OTA Update comes with new features like emergency calling for India, motion detection in the camera, updated and redesigned apps, increased stability, and much more. Also, the Oxygen OS 3.5.3 official update for OnePlus 3T is an incremental update that rolls out in a phase-wise manner. You can install this update without losing any data. But still, we recommend you before proceeding, take a full backup of all your valuable data. If you are interested in updating your Oneplus 3T smartphone to Oxygen OS 3.5.3 official firmware, then follow the given steps. Oxygen OS 3.5.3 Official Firmware Features: \tAdded emergency calling for India (triple press the power button to trigger) \tAdded motion detection in camera and enhanced image capturing quality \tAdded OnePlus community app \tUpdated touch panel firmware and optimized touch precision \tUpdated GPS library and optimized location accuracy \tRedesigned clock UI \tRedesigned calling UI \tIncreased stability and implemented various bug fixes Note: This guide containing the rooted and cleaned Oxygen OS 3.5.3 Update can be used for the OnePlus 3T devices only. Do not try to install this firmware on any other device or incorrect variant. It is recommended to check the model number of your device first. Warning: AndroidBlog will not be held responsible for any kind of damage occurred to your OnePlus 3T device during or after the installation of Oxygen OS 3.5.3 Update. Proceed at your own risk. Pre-Requirements: \tCreate a proper backup of all your existing data and settings on the phone before proceeding to the installation guide using a recommended custom recovery. \tEnable USB Debugging Mode on the OnePlus 3T by navigating to Settings > Developer Options. \tVerify that you’ve properly installed the OnePlus 3T USB Drivers on the PC. \tYour device should be rooted with the latest version of a custom recovery like CWM or TWRP installed. \tThe bootloader of your OnePlus 3T must be unlocked. \tMake sure that the battery level of the device is above 80% before going ahead. Required Files: \tDownload Oxygen OS 3.5.3 Official Update Steps to update OnePlus 3T to Oxygen OS 3.5.3 Official Update Android 6.0.1 Marshmallow: Step No 1: First, setup ADB and Fastboot on your PC. Step No 2: Download the Oxygen OS 3.5.3 official file on the desktop of your PC from the above-given link and rename it to ota.zip Step No 3: Next, Enable USB Debugging on your Oneplus 3T by navigating to Setting > Developer Options. Step No 4: Connect your OnePlus 3T with your PC/laptop. Step No 5: Open the folder where you have placed the downloaded OTA.zip file and open command windows within the folder. Step No 6: Type the following command and hit Enter to reboot your phone into Recovery Mode. adb reboot recovery Step No 7: Select the “Install from USB” option in Recovery Mode. Step No 8: Type the following command and hit Enter. adb sideloaded ota.zip Step No 9: The installation process will be initiated, so wait for the installation process to be completed. Once the process is finished, select reboot from the main Recovery Menu. Done! You have successfully installed the OxygenOS 3.5.3 update on OnePlus 3T.