diff --git a/src/components/Grid.tsx b/src/components/Grid.tsx
index 34a3b2c0..78937e1e 100644
--- a/src/components/Grid.tsx
+++ b/src/components/Grid.tsx
@@ -115,11 +115,13 @@ export const Grid = ({
   selectColumnPinned = null,
   contextMenuSelectRow = false,
   singleClickEdit = false,
+  rowData,
   rowHeight = theme === "ag-theme-step-default" ? 40 : theme === "ag-theme-step-compact" ? 36 : undefined,
   ...params
 }: GridProps): ReactElement => {
   const {
     gridReady,
+    gridRenderState,
     setApis,
     ensureRowVisible,
     getFirstRowId,
@@ -153,36 +155,38 @@ export const Grid = ({
    */
   const hasSetContentSize = useRef(false);
   const hasSetContentSizeEmpty = useRef(false);
-  const needsAutoSize = useRef(false);
+  const needsAutoSize = useRef(true);
 
   const setInitialContentSize = useCallback(() => {
-    if (!gridDivRef.current?.clientWidth) {
+    if (!gridDivRef.current?.clientWidth || rowData == null) {
       // Don't resize grids if they are offscreen as it doesn't work.
       needsAutoSize.current = true;
       return;
     }
 
-    const headerCellCount = gridDivRef.current?.getElementsByClassName("ag-header-cell-label")?.length;
-    if (headerCellCount < 2) {
-      // Don't resize grids until all the columns are visible
-      // as `autoSizeColumns` will fail silently in this case
+    const gridRendered = gridRenderState();
+    if (gridRendered === null) {
+      // Don't resize until grid has rendered, or it has 0 rows.
       needsAutoSize.current = true;
       return;
     }
 
-    const skipHeader = sizeColumns === "auto-skip-headers" && !isEmpty(params.rowData);
+    const skipHeader = sizeColumns === "auto-skip-headers" && gridRendered === "rows-visible";
     if (sizeColumns === "auto" || skipHeader) {
       const result = autoSizeColumns({ skipHeader, userSizedColIds: userSizedColIds.current, includeFlex: true });
-      if (isEmpty(params.rowData)) {
+      if (gridRendered === "empty") {
         if (!hasSetContentSizeEmpty.current && result && !hasSetContentSize.current) {
           hasSetContentSizeEmpty.current = true;
           params.onContentSize && params.onContentSize(result);
         }
-      } else {
+      } else if (gridRendered === "rows-visible") {
         if (result && !hasSetContentSize.current) {
           hasSetContentSize.current = true;
           params.onContentSize && params.onContentSize(result);
         }
+      } else {
+        // It should be impossible to get here
+        console.error("Unknown value returned from hasGridRendered");
       }
     }
 
@@ -191,7 +195,7 @@ export const Grid = ({
     }
     setAutoSized(true);
     needsAutoSize.current = false;
-  }, [autoSizeColumns, params, sizeColumns, sizeColumnsToFit]);
+  }, [autoSizeColumns, gridRenderState, params, rowData, sizeColumns, sizeColumnsToFit]);
 
   const lastOwnerDocumentRef = useRef<Document>();
 
@@ -213,25 +217,17 @@ export const Grid = ({
         setInitialContentSize();
       }
     },
-    timeoutMs: 1000,
+    timeoutMs: 200,
   });
 
-  const previousGridReady = useRef(gridReady);
-  useEffect(() => {
-    if (!previousGridReady.current && gridReady) {
-      previousGridReady.current = true;
-      setInitialContentSize();
-    }
-  }, [gridReady, setInitialContentSize]);
-
   /**
    * On data load select the first row of the grid if required.
    */
   const hasSelectedFirstItem = useRef(false);
   useEffect(() => {
-    if (!gridReady || hasSelectedFirstItem.current || !params.rowData || !externallySelectedItemsAreInSync) return;
+    if (!gridReady || hasSelectedFirstItem.current || !rowData || !externallySelectedItemsAreInSync) return;
     hasSelectedFirstItem.current = true;
-    if (isNotEmpty(params.rowData) && isEmpty(params.externalSelectedItems)) {
+    if (isNotEmpty(rowData) && isEmpty(params.externalSelectedItems)) {
       const firstRowId = getFirstRowId();
       if (params.autoSelectFirstRow) {
         selectRowsById([firstRowId]);
@@ -245,7 +241,7 @@ export const Grid = ({
     gridReady,
     params.externalSelectedItems,
     params.autoSelectFirstRow,
-    params.rowData,
+    rowData,
     selectRowsById,
     getFirstRowId,
   ]);
@@ -402,7 +398,7 @@ export const Grid = ({
   const previousRowDataLength = useRef(0);
 
   const onRowDataChanged = useCallback(() => {
-    const length = params.rowData?.length ?? 0;
+    const length = rowData?.length ?? 0;
     if (previousRowDataLength.current !== length) {
       setInitialContentSize();
       previousRowDataLength.current = length;
@@ -417,7 +413,7 @@ export const Grid = ({
     const skipHeader = sizeColumns === "auto-skip-headers";
     autoSizeColumns({ skipHeader, userSizedColIds: userSizedColIds.current, colIds: colIdsEdited.current });
     colIdsEdited.current.clear();
-  }, [autoSizeColumns, params.rowData?.length, setInitialContentSize, sizeColumns, updatedDep, updatingCols]);
+  }, [autoSizeColumns, rowData?.length, setInitialContentSize, sizeColumns, updatedDep, updatingCols]);
 
   /**
    * Show/hide no rows overlay when model changes.
@@ -619,7 +615,6 @@ export const Grid = ({
 
       //we don't want to show the row highlight if it wouldn't result in the row moving
       const targetIndex = event.overIndex + position - (event.node.rowIndex < event.overIndex ? 1 : 0);
-      //console.log(targetIndex)
       if (event.node.rowIndex != targetIndex) {
         clientSideRowModel.highlightRowAtPixel(event.node as RowNode<any>, event.y);
       }
@@ -663,7 +658,7 @@ export const Grid = ({
         theme,
         "theme-specific",
         staleGrid && "Grid-sortIsStale",
-        gridReady && params.rowData && autoSized && "Grid-ready",
+        gridReady && rowData && autoSized && "Grid-ready",
       )}
     >
       {gridContextMenu.component}
@@ -691,7 +686,7 @@ export const Grid = ({
           onColumnResized={onColumnResized}
           defaultColDef={{ minWidth: 48, ...omit(params.defaultColDef, ["editable"]) }}
           columnDefs={columnDefsAdjusted}
-          rowData={params.rowData}
+          rowData={rowData}
           noRowsOverlayComponent={(event: AgGridEvent) => {
             let rowCount = 0;
             event.api.forEachNode(() => rowCount++);
diff --git a/src/contexts/GridContext.tsx b/src/contexts/GridContext.tsx
index b11ccfaa..612ebae6 100644
--- a/src/contexts/GridContext.tsx
+++ b/src/contexts/GridContext.tsx
@@ -17,6 +17,7 @@ export type AutoSizeColumnsResult = { width: number } | null;
 
 export interface GridContextType<RowType extends GridBaseRow> {
   gridReady: boolean;
+  gridRenderState: () => null | "empty" | "rows-visible";
   getColDef: (colId?: string) => ColDef | undefined;
   getColumns: (
     filter?: keyof ColDef | ((r: ColDef) => boolean | undefined | null | number | string),
@@ -68,6 +69,7 @@ export interface GridContextType<RowType extends GridBaseRow> {
 
 export const GridContext = createContext<GridContextType<any>>({
   gridReady: false,
+  gridRenderState: () => null,
   getColDef: () => {
     console.error("no context provider for getColDef");
     return undefined;
diff --git a/src/contexts/GridContextProvider.tsx b/src/contexts/GridContextProvider.tsx
index d060e03b..fbe9bd1a 100644
--- a/src/contexts/GridContextProvider.tsx
+++ b/src/contexts/GridContextProvider.tsx
@@ -104,6 +104,17 @@ export const GridContextProvider = <RowType extends GridBaseRow>(props: PropsWit
     [quickFilter],
   );
 
+  /**
+   * Used to check if it's OK to autosize.
+   */
+  const gridRenderState = useCallback((): null | "empty" | "rows-visible" => {
+    if (!gridApi) return null;
+    if (!gridApi.getModel().isRowsToRender()) return "empty";
+    if (!isEmpty(gridApi.getRenderedNodes())) return "rows-visible";
+    // If there are rows to render, but there are no rendered nodes then we should wait
+    return null;
+  }, [gridApi]);
+
   /**
    * Expose scrollRowIntoView for playwright tests.
    */
@@ -701,6 +712,7 @@ export const GridContextProvider = <RowType extends GridBaseRow>(props: PropsWit
   return (
     <GridContext.Provider
       value={{
+        gridRenderState,
         getColDef,
         getColumns,
         getColumnIds,
diff --git a/src/stories/grid/GridReadOnly.stories.tsx b/src/stories/grid/GridReadOnly.stories.tsx
index 61b73653..d25a2998 100644
--- a/src/stories/grid/GridReadOnly.stories.tsx
+++ b/src/stories/grid/GridReadOnly.stories.tsx
@@ -66,7 +66,7 @@ interface ITestRow {
   id: number;
   position: string;
   age: number;
-  height: number;
+  height: string;
   desc: string;
   dd: string;
 }
@@ -215,7 +215,7 @@ const GridReadOnlyTemplate: ComponentStory<typeof Grid> = (props: GridProps) =>
     { id: 1000, position: "Tester", age: 30, height: `6'4"`, desc: "Tests application", dd: "1" },
     { id: 1001, position: "Developer", age: 12, height: `5'3"`, desc: "Develops application", dd: "2" },
     { id: 1002, position: "Manager", age: 65, height: `5'9"`, desc: "Manages", dd: "3" },
-  ]);
+  ] as ITestRow[]);
 
   return (
     <GridWrapper maxHeight={300}>