The grid is fast. However, the grid can also be configured and extended in many ways. This page explains how you can make the grid go faster.
React in Production Mode works faster than Dev Mode. Given the DOM complexity of the grid, React Production Mode will allow the grid to perform optimally without any overhead introduced by Dev Mode. Performance testing should be performed in Production Mode only.
Setting Expectations
The grid can be as fast as demonstrated in the Demo. You can resize the demo application to the same size as the grid in your application by resizing the browser, then navigate around the grid (scroll, filter, etc.) and see how fast the demo grid is compared to your own implementation. If the demo grid is going faster, then there is room for performance improvements.
Check Cell Renderers
The grid can be slowed down by custom Cell Renderers. To test this, remove all Cell Renderers from the grid and compare the speed again. If the grid does improve its speed by removing Cell Renderers, introduce the Cell Renderers one by one to find out which ones are adding the most overhead.
If Possible, Avoid Cell Renderers
Cell Renders result in more DOM. More DOM means more CPU processing to render, regardless of what JavaScript / Framework is used to generate the DOM.
Ask the question, do you really need the Cell Renderer?
If you are only manipulating the value rather than creating complex DOM, would a Value Getter or Value Formatter achieve what you want instead? Value Getters and Value Formatters do not result in more DOM.
Avoid Auto Height
Auto Height Rows is a great feature that we love. However it also creates more complex DOM inside each Cell.
If you are looking for ways to squeeze performance, consider turning this feature off. As with all suggestions here, it is paramount you profile your own application with this suggestion to see how much of a difference it makes and if the trade off is worth it for your application.
Configure Row Buffer
The rowBuffer property sets the number of rows the grid renders outside of the viewable area. The default is 10. For example, if your grid is showing 50 rows (as that's all that fits on your screen without scrolling),then the grid will actually render 70 in total (10 extra above and 10 extra below). Then when you scroll, the grid will already have 10 rows ready and waiting to show, so the user will not see a redraw (not all browsers show the redraw, only the slower ones).
Setting a low row buffer will make initial draws of the grid faster (e.g. when data is first loaded, or after filtering, grouping, etc.). Setting a high row buffer will reduce the redraw visible vertically scrolling.
Debounce Vertical Scroll
By default, there is no debouncing of the vertical scroll. However, in some rare circumstances, you may wish to debounce the vertical scroll so that the grid only scrolls after the user has finished updating the scroll position.
To debounce the vertical scroll, set grid property debounceVerticalScrollbar=true.
Disable Row Highlighting
By default, rows are highlighted as the mouse hovers over them. As Row Highlighting works by the grid adding the CSS class ag-row-hover to each row getting hovered you may see an increase in scrolling performance by disabling this.
To disable row highlighting, set the grid property suppressRowHoverHighlight=true