On Windows, open Settings > System > About and look for Installed RAM
On Windows, press Ctrl + Shift + Esc, open Task Manager, and check Memory under the Performance tab
On Windows, press Win + R, type msinfo32, and check Installed Physical Memory
On Mac, click the Apple menu > About This Mac and look for Memory
On Linux, open a terminal and run free -h
On Linux, run cat /proc/meminfo and check MemTotal
On Linux, run sudo dmidecode -t memory for detailed RAM information
On Android, go to Settings > About phone > RAM or Memory
On iPhone, go to Settings > General > About and check device specifications through the model details
On Chromebook, open Settings > About ChromeOS > Diagnostics or use the system information page
On any computer, check the device specifications label or manufacturer documentation if the operating system is unavailable