Whenever a new system update is released, Google makes the factory images for Nexus devices available on its developer website. While these updates can be downloaded right away, the problem is you need to have an unlocked bootloader to flash them. And if you can’t seem to track down the OTA (.zip file) for that particular update, you’re stuck waiting until the over-the-air update rolls out to your device, which could be days after the initial release. That actually won’t be a problem anymore.
Google is now making OTA files available for download alongside the factory images. Yes, really.
No need to unlock your bootloader to get early updates, no need to worry about factory data resets. Just download the proper OTA .zip file, use a few adb commands, and you’re updated.
Along with this change, Google is also implementing a Terms and Conditions section that you must agree to before getting access to any of the links.
OTA images for the Pixel C, Nexus 6P, Nexus 5X, Nexus 6, Nexus 5, 2013 Nexus 7 (Wi-Fi and mobile), Nexus 9 and Nexus Player can be found at this link. It looks like only recent updates (Android 6.0.1 Marshmallow) are being added at this time.
Not only will this make it easier for users to get updates faster, it also allows folks to keep their bootloaders locked and their devices more secure.