Magento 2 - Autologin for customer (frontend) and user (admin panel)
Admin can activate autologin for customer and admin.

For good work recommended in "Settings -> Advanced - Admin - Security" set next settings:
"Yes" for "Admin Account Sharing"
"No" for "Add Secret Key to URLs"

Note: if activated autologin for admin, you can't sign out.

Magento 2.1.x - 2.3.x
Magento 2.0 - correct work is not guaranteed
PHP 5.6
PHP 7.0 and higher

• Copy the content of the repo to the Magento 2: app/code/Nans/AutoLogin
• Run command: php bin/magento setup:upgrade
• Run command: php bin/magento cache:clean

If you encounter any problems or bugs, please open an issue on GitHub.

For frontend: php bin/magento autologin:disable f
For backend: php bin/magento autologin:disable b
For backend and frontend: php bin/magento autologin:disable all

After command execute, for clean cache run command: php bin/magento cache:clean