Warning: The HTC One (GSM) is no longer maintained. A build guide is available for developers that would like to make private builds, or even restart official support.
Special boot modes
Recovery: With the device powered off, hold Volume Down + Power.
Find help online
Note: This page is auto-generated for the HTC One (GSM), based on the device’s information, located here. You can find similar instructions for every officially-supported device on this wiki.