diff --git a/lib/core/csv/result_grid_csv.dart b/lib/core/csv/result_grid_csv.dart
index f58e157f..7b4a2f33 100644
--- a/lib/core/csv/result_grid_csv.dart
+++ b/lib/core/csv/result_grid_csv.dart
@@ -2,7 +2,6 @@
 library;
 
 import 'dart:io';
-import 'dart:isolate';
 
 String escapeCsvField(String s) {
   final needsQuotes = s.contains(',') ||
@@ -27,8 +26,9 @@ String formatCsvDataRow(List<String> row, int columnCount) {
 
 /// One line per row; pads short rows with empty cells to [columns.length].
 ///
-/// Prefer [resultGridAsCsvAsync] for large grids on the UI isolate, and
-/// [writeResultGridCsv] when writing to a file.
+/// For large grids use [writeResultGridCsv] when writing to a file;
+/// `DataExportService.formatAsync` runs this off the UI isolate for the
+/// clipboard.
 String resultGridAsCsv(List<String> columns, List<List<String>> rows) {
   final buf = StringBuffer();
   buf.write(columns.map(escapeCsvField).join(','));
@@ -39,14 +39,6 @@ String resultGridAsCsv(List<String> columns, List<List<String>> rows) {
   return buf.toString();
 }
 
-/// Builds CSV off the UI isolate so large grids do not freeze the main thread.
-Future<String> resultGridAsCsvAsync(
-  List<String> columns,
-  List<List<String>> rows,
-) {
-  return Isolate.run(() => resultGridAsCsv(columns, rows));
-}
-
 /// Streams CSV to [sink] without assembling the full document in memory.
 Future<void> writeResultGridCsv(
   IOSink sink, {
diff --git a/test/core/csv/result_grid_csv_test.dart b/test/core/csv/result_grid_csv_test.dart
index 6c5d75c2..b29fea9d 100644
--- a/test/core/csv/result_grid_csv_test.dart
+++ b/test/core/csv/result_grid_csv_test.dart
@@ -32,18 +32,6 @@ void main() {
     });
   });
 
-  group('resultGridAsCsvAsync', () {
-    test('matches synchronous result off the UI isolate', () async {
-      const columns = ['a', 'b'];
-      const rows = [
-        ['1', 'two,comma'],
-        ['quote', 'say "hi"'],
-      ];
-      final asyncCsv = await resultGridAsCsvAsync(columns, rows);
-      expect(asyncCsv, resultGridAsCsv(columns, rows));
-    });
-  });
-
   group('writeResultGridCsv', () {
     test('streams the same content as resultGridAsCsv', () async {
       const columns = ['a', 'b'];