Welcome to the Community forum, @mahesh-grubtech-.t. I can share some information about why your QuickBooks Online (QBO) account slow and how you can improve its overall performance.
QBO is a web-based accounting service. It relies on your computer or device’s processing power, the available memory (RAM), and your Internet connection speed.
To get the best experience possible when using QBO, I suggest checking if your operating system is up to date and meets the basic requirements to help narrow down the reason for slow performance: System Requirements for QuickBooks Online.