Recently, Google released a preview version of Android 7.1 Nougat for supported devices with new features and fixes. Since then, developer communities are busy porting Android 7.1 Nougat for officially unsupported devices like Nexus 5. An AOSP (Android open source project) based, fully working port of Android 7.1 Nougat custom ROM is available for Nexus 5 that you can install and experience new features on your Nexus 5.
The AOSP Nougat for Nexus 5 ROM is based on Android 7.1.1 Nougat Developer Preview (NDE63P) and fully functional. Note that this release build is considered stable, but there are some flaws that hopefully will be fixed in the upcoming releases. If you are ready to face few issues and excited to try the new Android 7.1 Nougat on your Nexus 5, then follow the installation instruction.
Android 7.1 Nougat includes new features such as, app shortcuts, image keyboard support, various bug fixes and more. Before start installing the Android 7.1 based custom ROM on Nexus 5, note that your device should be rooted and latest version of TWRP recovery installed on it.
Android 7.1 Nougat includes new features such as, app shortcuts, image keyboard support, various bug fixes and more.
Note: Backup any important data you have on your phone before proceeding with the below steps.
Disclaimer: Please follow this guide at your own risk. We can’t take responsibility for anything that goes wrong. This guide is intended for technically talented users only.
1. Download AOSP Android 7.1 ROM zip file from the development page [HERE] and transfer it to the internal storage of your Nexus 5.
3. Disconnect your phone form PC, then turn it off and boot into TWRP recovery mode by pressing and holding Volume down and Power buttons simultaneously.
4. In TWRP recovery, select Wipe and wipe cache partition, dalvik cache and wipe data/factory reset.
6. Once flashing the ROM and Gapps finished, reboot your device.
Note: If your device stuck at boot, boot it into recovery mode and wipe data, dalvic cache and factory reset. Then reboot it. (Source)