diff --git a/src/features/database/ExportDialog.test.tsx b/src/features/database/ExportDialog.test.tsx
new file mode 100644
index 000000000..3b06fa8c7
--- /dev/null
+++ b/src/features/database/ExportDialog.test.tsx
@@ -0,0 +1,37 @@
+import { fireEvent, render, screen, waitFor } from "@testing-library/react";
+import { describe, expect, it, vi } from "vitest";
+import { commands } from "@/platform/ipc";
+import { ExportDialog } from "./ExportDialog";
+import { cellPreview } from "./cellPreview";
+
+vi.mock("./store", () => ({ closeDialog: vi.fn() }));
+vi.mock("@/workbench/contributions", () => ({ notifications: () => ({ notify: vi.fn() }) }));
+vi.mock("@tauri-apps/api/path", () => ({ homeDir: async () => "/home/test" }));
+
+describe("large value export", () => {
+  it("bounds preview values while exporting every row in full", async () => {
+    const full = JSON.stringify({ text: "\u4e2d text ".repeat(200_000), tail: "complete" });
+    const dbExportFile = vi.spyOn(commands, "dbExportFile").mockResolvedValue({ status: "ok", data: null });
+    const rows = [[full], ["short"], [null]];
+    render(
+      <ExportDialog
+        data={{ columns: [{ name: "payload", type: "jsonb" }], rows, table: "big", driver: "postgres" }}
+        source="public.big"
+        initialFormat="json"
+      />,
+    );
+    const preview = screen.getByLabelText("Export preview");
+    expect(JSON.parse(preview.textContent!)).toEqual([
+      { payload: cellPreview(full) },
+      { payload: "short" },
+      { payload: null },
+    ]);
+    await waitFor(() => expect(screen.getByLabelText("Output file")).toHaveValue("/home/test/big.json"));
+    fireEvent.click(screen.getByRole("button", { name: "Export to File" }));
+    await waitFor(() => expect(dbExportFile).toHaveBeenCalled());
+    const [path, contents] = dbExportFile.mock.calls[0]!;
+    expect(path).toBe("/home/test/big.json");
+    expect(JSON.parse(contents)).toEqual(rows.map(([payload]) => ({ payload })));
+    dbExportFile.mockRestore();
+  });
+});
diff --git a/src/features/database/ExportDialog.tsx b/src/features/database/ExportDialog.tsx
index 269946355..b8d9b014b 100644
--- a/src/features/database/ExportDialog.tsx
+++ b/src/features/database/ExportDialog.tsx
@@ -17,6 +17,7 @@ import {
 import { CodePreview } from "./CodePreview";
 import { closeDialog } from "./store";
 import styles from "./Database.module.css";
+import { cellPreview } from "./cellPreview";
 
 const PREVIEW_ROWS = 100;
 /** Formats with a tabular layout (the options apply). */
@@ -59,7 +60,15 @@ export function ExportDialog({
   const tabular = TABULAR.has(format);
   const effective = tabular ? options : DEFAULT_EXPORT_OPTIONS;
   const preview = useMemo(
-    () => exportData(format, { ...data, rows: data.rows.slice(0, PREVIEW_ROWS) }, effective),
+    () =>
+      exportData(
+        format,
+        {
+          ...data,
+          rows: data.rows.slice(0, PREVIEW_ROWS).map((row) => row.map((v) => (v === null ? null : cellPreview(v)))),
+        },
+        effective,
+      ),
     [format, data, effective],
   );
   const text = () => exportData(format, data, effective);
diff --git a/src/features/database/Grid.test.tsx b/src/features/database/Grid.test.tsx
index 2c7e73aa5..200defe81 100644
--- a/src/features/database/Grid.test.tsx
+++ b/src/features/database/Grid.test.tsx
@@ -2,7 +2,8 @@ import { installKeyboardDispatcher, useKeymap } from "@/platform/keymap";
 import { registerActions } from "@/platform/actions";
 import { fireEvent, render, screen } from "@testing-library/react";
 import { afterEach, describe, expect, it, vi } from "vitest";
-import { CELL_PREVIEW_LIMIT, cellPreview, Grid } from "./Grid";
+import { Grid } from "./Grid";
+import { CELL_PREVIEW_LIMIT, cellPreview } from "./cellPreview";
 import { exportData } from "./export";
 
 vi.mock("@tanstack/react-virtual", () => ({
diff --git a/src/features/database/Grid.tsx b/src/features/database/Grid.tsx
index 0865878c1..6711165e9 100644
--- a/src/features/database/Grid.tsx
+++ b/src/features/database/Grid.tsx
@@ -10,6 +10,7 @@ import { Dialog, Icon, showContextMenu, type MenuItem } from "@/ui";
 import { parseDelimited, toCsv, toTsv, type Cell } from "./model";
 import styles from "./Database.module.css";
 import { tx } from "@/platform/i18n";
+import { CELL_PREVIEW_LIMIT, cellPreview } from "./cellPreview";
 
 export interface GridColumn {
   name: string;
@@ -69,17 +70,6 @@ interface Sel {
   c1: number;
 }
 
-export const CELL_PREVIEW_LIMIT = 1000;
-
-/** Bound text layout without changing the underlying value or splitting a surrogate pair. */
-export function cellPreview(value: string): string {
-  if (value.length <= CELL_PREVIEW_LIMIT) return value;
-  let end = CELL_PREVIEW_LIMIT;
-  const last = value.charCodeAt(end - 1);
-  if (last >= 0xd800 && last <= 0xdbff) end--;
-  return value.slice(0, end) + "\u2026";
-}
-
 const ROW_H = 24;
 const NUM_W = 48;
 
diff --git a/src/features/database/cellPreview.ts b/src/features/database/cellPreview.ts
new file mode 100644
index 000000000..c0a69b4d1
--- /dev/null
+++ b/src/features/database/cellPreview.ts
@@ -0,0 +1,10 @@
+export const CELL_PREVIEW_LIMIT = 1000;
+
+/** Bound text layout without changing the underlying value or splitting a surrogate pair. */
+export function cellPreview(value: string): string {
+  if (value.length <= CELL_PREVIEW_LIMIT) return value;
+  let end = CELL_PREVIEW_LIMIT;
+  const last = value.charCodeAt(end - 1);
+  if (last >= 0xd800 && last <= 0xdbff) end--;
+  return value.slice(0, end) + "\u2026";
+}