Free Up Disk Space
Your computer is happiest when it has at leat 10 GB of disk space free. This space is actually used by the memory management systems in your computer to allocate virtual memory.
Check memory usage and install RAM
A computer that is low on real, physical memory can also underperform.
Close unused browser tabs
An active browser with many tabs is actively consuming RAM and memory resources. Get into the habit of closing your inactive browser tabs to increase the performance of your Mac.