[Magento 2] How to change backend session timeout. You may set the value in: Stores->Settings->Configuration->Advanced->Admin->Security->Admin Session Lifetime. Valid values are between 60 (one minute) and 31536000 (one year). Both values are nonsense, but you will find a good value between. If you set this value to maximum, sessions may are stored one year. This may not be a good idea. My recommendation is to set it to one day (86400), or to maximum of a week (604800).