diff --git a/apps/desktop/src/components/grid/DataGrid.vue b/apps/desktop/src/components/grid/DataGrid.vue
index cc7d37b8a5..0062f64c33 100644
--- a/apps/desktop/src/components/grid/DataGrid.vue
+++ b/apps/desktop/src/components/grid/DataGrid.vue
@@ -701,6 +701,8 @@ const columnCommentMap = computed(() => {
 });
 const dataGridTopbarWidth = ref(0);
 const dataGridViewportWidth = ref(0);
+const dataGridTopbarOverflowCompact = ref(false);
+const dataGridTopbarExpandedRequiredWidth = ref(0);
 const showColumnCommentsInHeader = computed(() => settingsStore.editorSettings.showColumnCommentsInHeader);
 const showColumnTypesInHeader = computed(() => settingsStore.editorSettings.showColumnTypesInHeader);
 const showTransposeFieldMetadata = computed(() => settingsStore.editorSettings.dataGridShowTransposeFieldMetadata);
@@ -720,7 +722,7 @@ const columnIndexMap = computed(() => buildColumnIndexMap(indexes.value, primary
 const compactColumnHeaderActions = computed(() => settingsStore.editorSettings.compactColumnHeaderActions);
 const dataGridRenderMode = computed(() => settingsStore.editorSettings.dataGridRenderMode);
 const dataGridSearchMode = computed(() => settingsStore.editorSettings.dataGridSearchMode);
-const compactDataGridToolbar = computed(() => isDataGridToolbarCompact(dataGridTopbarWidth.value, dataGridViewportWidth.value, DATA_GRID_CONDITION_TOOLBAR_MIN_WIDTH));
+const compactDataGridToolbar = computed(() => dataGridTopbarOverflowCompact.value || isDataGridToolbarCompact(dataGridTopbarWidth.value, dataGridViewportWidth.value, DATA_GRID_CONDITION_TOOLBAR_MIN_WIDTH));
 const infiniteScrollEnabled = computed(() => props.paginationEnabled && settingsStore.editorSettings.infiniteScroll);
 const queryResultMaxRows = computed(() => effectiveQueryResultMaxRows(settingsStore.editorSettings.queryResultMaxRowsEnabled, settingsStore.editorSettings.queryResultMaxRows));
 const paginationMaxRows = computed(() => (isResultsContext.value ? queryResultMaxRows.value : undefined));
@@ -2535,6 +2537,8 @@ let gridVerticalScrollbarThumbTopPercent = 0;
 let gridVerticalScrollbarThumbHeightPercent = 100;
 let gridScrollbarsRuntime: DataGridScrollbarsRuntime;
 let dataGridTopbarResizeObserver: ResizeObserver | null = null;
+let dataGridTopbarMutationObserver: MutationObserver | null = null;
+let dataGridTopbarRecheckTimer: ReturnType<typeof setTimeout> | null = null;
 let cellEditResizeObserver: ResizeObserver | null = null;
 // vue-virtual-scroller's @resize only fires in pageMode (it observes window),
 // so in container-scroll mode (transpose uses RecycleScroller without pageMode)
@@ -3183,19 +3187,68 @@ function observeGridHorizontalScrollbarScroller() {
 }
 
 function updateDataGridTopbarWidth() {
-  dataGridTopbarWidth.value = dataGridTopbarRef.value?.clientWidth ?? 0;
+  const topbar = dataGridTopbarRef.value;
+  dataGridTopbarWidth.value = topbar?.clientWidth ?? 0;
   dataGridViewportWidth.value = typeof window === "undefined" ? 0 : window.innerWidth;
+
+  if (!topbar) return;
+
+  const fixedBreakpointCompact = isDataGridToolbarCompact(dataGridTopbarWidth.value, dataGridViewportWidth.value, DATA_GRID_CONDITION_TOOLBAR_MIN_WIDTH);
+  if (fixedBreakpointCompact) return;
+
+  if (dataGridTopbarOverflowCompact.value) {
+    if (dataGridTopbarWidth.value >= dataGridTopbarExpandedRequiredWidth.value) {
+      dataGridTopbarOverflowCompact.value = false;
+      dataGridTopbarExpandedRequiredWidth.value = 0;
+    }
+    return;
+  }
+
+  // The action list gains preview/save/rollback controls in editable grids. The
+  // fixed breakpoint cannot see that extra width, so capture the full layout
+  // width before the overflow-clip wrapper can hide the trailing action.
+  if (topbar.scrollWidth > topbar.clientWidth + 1) {
+    dataGridTopbarExpandedRequiredWidth.value = topbar.scrollWidth;
+    dataGridTopbarOverflowCompact.value = true;
+  }
+}
+
+function resetDataGridTopbarOverflowCompact() {
+  if (!dataGridTopbarOverflowCompact.value) return;
+  dataGridTopbarOverflowCompact.value = false;
+  dataGridTopbarExpandedRequiredWidth.value = 0;
+  if (dataGridTopbarRecheckTimer) clearTimeout(dataGridTopbarRecheckTimer);
+  // Wait for the label-width transition to finish before measuring the newly
+  // shortened action list. If it still overflows, updateDataGridTopbarWidth
+  // captures its new, smaller expanded width.
+  dataGridTopbarRecheckTimer = setTimeout(() => {
+    dataGridTopbarRecheckTimer = null;
+    updateDataGridTopbarWidth();
+  }, 360);
+}
+
+function clearDataGridTopbarRecheckTimer() {
+  if (!dataGridTopbarRecheckTimer) return;
+  clearTimeout(dataGridTopbarRecheckTimer);
+  dataGridTopbarRecheckTimer = null;
 }
 
 function observeDataGridTopbarWidth() {
   dataGridTopbarResizeObserver?.disconnect();
   dataGridTopbarResizeObserver = null;
+  dataGridTopbarMutationObserver?.disconnect();
+  dataGridTopbarMutationObserver = null;
+  clearDataGridTopbarRecheckTimer();
   const topbar = dataGridTopbarRef.value;
   updateDataGridTopbarWidth();
   if (topbar && typeof ResizeObserver !== "undefined") {
     dataGridTopbarResizeObserver = new ResizeObserver(updateDataGridTopbarWidth);
     dataGridTopbarResizeObserver.observe(topbar);
   }
+  if (topbar && typeof MutationObserver !== "undefined") {
+    dataGridTopbarMutationObserver = new MutationObserver(updateDataGridTopbarWidth);
+    dataGridTopbarMutationObserver.observe(topbar, { childList: true, characterData: true, subtree: true });
+  }
 }
 
 function applyPendingGridHorizontalScrollbarDrag(clientX: number) {
@@ -4843,6 +4896,21 @@ const previewToolbarCapability = computed<DataGridToolbarActionCapability>(() =>
   loading: isPreviewLoading.value,
   onTrigger: openSqlPreview,
 }));
+watch(
+  () => previewToolbarCapability.value.visible,
+  (visible, previousVisible) => {
+    if (previousVisible && !visible) resetDataGridTopbarOverflowCompact();
+  },
+);
+// Save/rollback disappear with saveToolbarState.showActions (committing or
+// discarding all pending edits), which shortens the action list while compact
+// just like the preview action disappearing does.
+watch(
+  () => saveToolbarState.value.showActions,
+  (showActions, previousShowActions) => {
+    if (previousShowActions && !showActions) resetDataGridTopbarOverflowCompact();
+  },
+);
 const layerPreviewToolbarCapability = computed<DataGridToolbarActionCapability>(() => {
   const action = previewActions.value.find((candidate) => candidate.id === "geometry-map-preview");
   return {
@@ -7946,6 +8014,9 @@ function pauseCanvasGridWork() {
   disconnectCellEditResizeObserver();
   dataGridTopbarResizeObserver?.disconnect();
   dataGridTopbarResizeObserver = null;
+  dataGridTopbarMutationObserver?.disconnect();
+  dataGridTopbarMutationObserver = null;
+  clearDataGridTopbarRecheckTimer();
   disconnectTransposeViewportObserver();
   canvasPixelRatioMediaQueryCleanup?.();
   canvasPixelRatioMediaQueryCleanup = null;
@@ -8016,6 +8087,8 @@ onUnmounted(() => {
   canvasRuntime.dispose();
   gridScrollbarsRuntime.dispose();
   dataGridTopbarResizeObserver?.disconnect();
+  dataGridTopbarMutationObserver?.disconnect();
+  clearDataGridTopbarRecheckTimer();
   disconnectCellEditResizeObserver();
   disconnectTransposeViewportObserver();
   stopGridHorizontalScrollbarDrag();
diff --git a/packages/app-tests/queryResultToolbar.test.ts b/packages/app-tests/queryResultToolbar.test.ts
index ab9a2cdd26..350f8f70b3 100644
--- a/packages/app-tests/queryResultToolbar.test.ts
+++ b/packages/app-tests/queryResultToolbar.test.ts
@@ -169,6 +169,32 @@ test("standalone result views use the same compact toolbar breakpoint", () => {
   assert.match(dataGrid, /isDataGridToolbarCompact\(dataGridTopbarWidth\.value, dataGridViewportWidth\.value, DATA_GRID_CONDITION_TOOLBAR_MIN_WIDTH\)/);
 });
 
+test("embedded result toolbar compacts when editing actions overflow its available width", () => {
+  const dataGrid = source(dataGridPath);
+
+  assert.match(dataGrid, /dataGridTopbarMutationObserver = new MutationObserver\(updateDataGridTopbarWidth\)/);
+  assert.match(dataGrid, /dataGridTopbarMutationObserver\.observe\(topbar, \{ childList: true, characterData: true, subtree: true \}\)/);
+  assert.match(dataGrid, /topbar\.scrollWidth > topbar\.clientWidth \+ 1/);
+  assert.match(dataGrid, /dataGridTopbarOverflowCompact\.value = true/);
+  assert.match(dataGrid, /dataGridTopbarWidth\.value >= dataGridTopbarExpandedRequiredWidth\.value/);
+});
+
+test("embedded result toolbar remeasures after the SQL preview action is removed", () => {
+  const dataGrid = source(dataGridPath);
+
+  assert.match(dataGrid, /if \(previousVisible && !visible\) resetDataGridTopbarOverflowCompact\(\)/);
+  assert.match(dataGrid, /dataGridTopbarOverflowCompact\.value = false/);
+  assert.match(dataGrid, /dataGridTopbarRecheckTimer = setTimeout\(/);
+  assert.match(dataGrid, /clearDataGridTopbarRecheckTimer\(\)/);
+});
+
+test("embedded result toolbar remeasures after save and rollback actions are removed", () => {
+  const dataGrid = source(dataGridPath);
+
+  assert.match(dataGrid, /\(\) => saveToolbarState\.value\.showActions,/);
+  assert.match(dataGrid, /if \(previousShowActions && !showActions\) resetDataGridTopbarOverflowCompact\(\)/);
+});
+
 test("embedded and standalone result toolbars share the same fixed height", () => {
   const contentArea = source(contentAreaPath);
   const dataGrid = source(dataGridPath);