diff --git a/apps/desktop/src/components/grid/DataGridCellDetailDialog.vue b/apps/desktop/src/components/grid/DataGridCellDetailDialog.vue
index 39abb4c8d5..c223a43cb1 100644
--- a/apps/desktop/src/components/grid/DataGridCellDetailDialog.vue
+++ b/apps/desktop/src/components/grid/DataGridCellDetailDialog.vue
@@ -1,4 +1,5 @@
 <script setup lang="ts">
+import DataGridCellDetailTextPreview from "@/components/grid/DataGridCellDetailTextPreview.vue";
 import DataGridValueTransform from "@/components/grid/DataGridValueTransform.vue";
 import { computed, nextTick, ref, watch } from "vue";
 import { Code2, Copy, Download, Eye, FileUp, Info, Pencil } from "@lucide/vue";
@@ -150,8 +151,12 @@ watch(
           <div class="flex items-center justify-between gap-2">
             <div class="text-muted-foreground">{{ t("grid.cellValue") }}</div>
             <div class="flex items-center gap-1">
+              <!-- Binary cells keep `0x<hex>` as the canonical value; the transform kinds below
+                   (timestamp/JSON/radix…) have text semantics and would misread hex. Offer the
+                   explicit, read-only bytes decode instead. -->
+              <DataGridCellDetailTextPreview v-if="open && isBinaryCellColumnType(detail.type)" :identity="`${detail.rowId}:${detail.colIndex}`" :value="detail.value" :column-type="detail.type" :database-type="databaseType" :incomplete="detail.isSourceTruncated" />
               <DataGridValueTransform
-                v-if="open && !isBinaryCellColumnType(detail.type)"
+                v-else-if="open"
                 :source="(detail.isNull ?? detail.value === null) ? null : detail.rawValue"
                 :identity="`${detail.rowId}:${detail.colIndex}`"
                 :incomplete="detail.isSourceTruncated"
diff --git a/apps/desktop/src/components/grid/DataGridCellDetailPanel.vue b/apps/desktop/src/components/grid/DataGridCellDetailPanel.vue
index 90deaecfd5..c9aefd92f2 100644
--- a/apps/desktop/src/components/grid/DataGridCellDetailPanel.vue
+++ b/apps/desktop/src/components/grid/DataGridCellDetailPanel.vue
@@ -1,4 +1,5 @@
 <script setup lang="ts">
+import DataGridCellDetailTextPreview from "@/components/grid/DataGridCellDetailTextPreview.vue";
 import DataGridValueTransform from "@/components/grid/DataGridValueTransform.vue";
 import { computed, toRef } from "vue";
 import { Code2, Copy, Download, Eye, FileDiff, FileUp, Pencil, X } from "@lucide/vue";
@@ -142,8 +143,10 @@ defineExpose({ openSearch });
         <div class="flex min-h-5 min-w-0 flex-wrap items-center justify-between gap-2">
           <div class="shrink-0 text-muted-foreground">{{ t("grid.cellValue") }}</div>
           <div class="min-w-0 flex flex-1 flex-wrap items-center justify-end gap-1">
+            <!-- 与下载菜单同一道闸门：两者都读已提交的 `0x<hex>`，编辑中不对草稿做只读文本预览。 -->
+            <DataGridCellDetailTextPreview v-if="!editing && isBinaryCellColumnType(detail.type)" :identity="`${detail.rowId}:${detail.colIndex}`" :value="detail.value" :column-type="detail.type" :database-type="databaseType" :incomplete="detail.isSourceTruncated" />
             <DataGridValueTransform
-              v-if="!isBinaryCellColumnType(detail.type)"
+              v-else-if="!isBinaryCellColumnType(detail.type)"
               :source="(detail.isNull ?? detail.value === null) && (!editing || !detailEditValue || detailEditValue === detail.rawValue) ? null : editing ? detailEditValue : detail.rawValue"
               :identity="`${detail.rowId}:${detail.colIndex}:${editing}`"
               :incomplete="detail.isSourceTruncated"
diff --git a/apps/desktop/src/components/grid/DataGridCellDetailTextPreview.vue b/apps/desktop/src/components/grid/DataGridCellDetailTextPreview.vue
new file mode 100644
index 0000000000..41a6c0e7dd
--- /dev/null
+++ b/apps/desktop/src/components/grid/DataGridCellDetailTextPreview.vue
@@ -0,0 +1,84 @@
+<script setup lang="ts">
+import { computed, ref, watch } from "vue";
+import { useI18n } from "vue-i18n";
+import { copyToClipboard } from "@/lib/common/clipboard";
+import { useToast } from "@/composables/useToast";
+import { Button } from "@/components/ui/button";
+import { Dialog, DialogContent, DialogDescription, DialogHeader, DialogTitle, DialogTrigger } from "@/components/ui/dialog";
+import { BINARY_CELL_TEXT_ENCODINGS, binaryCellTextPreview, type BinaryCellTextEncoding } from "@/lib/dataGrid/binaryCellDownload";
+import type { DatabaseType } from "@/types/database";
+
+const props = defineProps<{
+  /** 单元格原始值（binary canonical form `0x<hex>`），只读使用。 */
+  value: unknown;
+  columnType?: string;
+  databaseType?: DatabaseType;
+  /** 单元格身份，切换单元格时重置字符集选择并关闭弹窗。 */
+  identity: string;
+  /** 后端返回的值本身不完整（大值预览闸门）时不解码残缺 bytes。 */
+  incomplete?: boolean;
+}>();
+
+const { t } = useI18n();
+const { toast } = useToast();
+const open = defineModel<boolean>("open", { default: false });
+const encoding = ref<BinaryCellTextEncoding>("utf8");
+
+// 只读 presentation：结果不回写 detail.value / rawValue，不进入编辑与提交路径。
+const preview = computed(() => binaryCellTextPreview(props.value, encoding.value, props.columnType, props.databaseType, props.incomplete));
+const decodedText = computed(() => (preview.value.ok ? preview.value.text : ""));
+const byteLength = computed(() => (preview.value.ok ? preview.value.byteLength : 0));
+const errorKey = computed(() => (preview.value.ok ? "" : `grid.binaryTextPreviewErrors.${preview.value.error}`));
+
+watch(
+  () => props.identity,
+  () => {
+    open.value = false;
+    encoding.value = "utf8";
+  },
+  { flush: "sync" },
+);
+
+async function copyResult() {
+  const result = preview.value;
+  if (!result.ok) return;
+  try {
+    await copyToClipboard(result.text);
+    toast(t("grid.cellValueCopied"), 2000);
+  } catch (error) {
+    toast(error instanceof Error ? error.message : String(error), 5000);
+  }
+}
+</script>
+
+<template>
+  <Dialog v-model:open="open">
+    <DialogTrigger as-child>
+      <Button variant="outline" size="sm" class="h-6 px-2 text-xs" @mousedown.prevent>{{ t("grid.binaryTextPreview") }}</Button>
+    </DialogTrigger>
+    <DialogContent class="flex max-h-[85vh] flex-col overflow-y-auto sm:max-w-2xl">
+      <DialogHeader>
+        <DialogTitle>{{ t("grid.binaryTextPreviewTitle") }}</DialogTitle>
+        <DialogDescription>{{ t("grid.binaryTextPreviewDescription") }}</DialogDescription>
+      </DialogHeader>
+      <div class="flex flex-wrap items-center gap-2 text-xs">
+        <span class="text-muted-foreground">{{ t("grid.binaryTextPreviewEncoding") }}</span>
+        <div class="flex items-center gap-1">
+          <Button v-for="item in BINARY_CELL_TEXT_ENCODINGS" :key="item" :variant="encoding === item ? 'secondary' : 'outline'" size="sm" class="h-7 px-2 text-xs" @click="encoding = item">
+            {{ t(`grid.binaryTextPreviewEncodings.${item}`) }}
+          </Button>
+        </div>
+        <span v-if="!errorKey" class="text-muted-foreground">{{ t("grid.binaryTextPreviewByteCount", { count: byteLength }) }}</span>
+      </div>
+      <p v-if="errorKey" role="alert" class="text-xs text-destructive">{{ t(errorKey) }}</p>
+      <template v-else>
+        <div class="flex items-center justify-between gap-2 text-xs">
+          <span>{{ t("grid.binaryTextPreviewResult") }}</span>
+          <Button variant="outline" size="sm" class="h-6 text-xs" @click="copyResult">{{ t("grid.binaryTextPreviewCopy") }}</Button>
+        </div>
+        <textarea :value="decodedText" :aria-label="t('grid.binaryTextPreviewResult')" readonly class="dbx-data-grid-value-font h-64 min-h-24 w-full resize-y rounded border bg-muted/20 p-3 text-xs" spellcheck="false" />
+      </template>
+      <p class="text-xs text-muted-foreground">{{ t("grid.binaryTextPreviewOriginalHint") }}</p>
+    </DialogContent>
+  </Dialog>
+</template>
diff --git a/apps/desktop/src/components/grid/__tests__/DataGridSurfaces.spec.ts b/apps/desktop/src/components/grid/__tests__/DataGridSurfaces.spec.ts
index 84405205da..6c6403ea20 100644
--- a/apps/desktop/src/components/grid/__tests__/DataGridSurfaces.spec.ts
+++ b/apps/desktop/src/components/grid/__tests__/DataGridSurfaces.spec.ts
@@ -12,6 +12,8 @@ const mocks = vi.hoisted(() => ({
   renderWkt: vi.fn(),
   panelCancel: vi.fn(),
   panelOpenSearch: vi.fn(),
+  copyToClipboard: vi.fn(),
+  toast: vi.fn(),
 }));
 
 vi.mock("vue-i18n", () => ({ useI18n: () => ({ t: (key: string) => key }) }));
@@ -53,7 +55,15 @@ vi.mock("@/components/ui/button", async () => ({ Button: (await import("./vueHos
 vi.mock("@/components/ui/input", async () => ({ Input: (await import("./vueHostHarness")).createPassthroughStub("Input", "input") }));
 vi.mock("@/components/ui/dialog", async () => {
   const { createPassthroughStub } = await import("./vueHostHarness");
-  return { Dialog: createPassthroughStub("Dialog"), DialogContent: createPassthroughStub("DialogContent"), DialogFooter: createPassthroughStub("DialogFooter"), DialogHeader: createPassthroughStub("DialogHeader"), DialogTitle: createPassthroughStub("DialogTitle") };
+  return {
+    Dialog: createPassthroughStub("Dialog"),
+    DialogContent: createPassthroughStub("DialogContent"),
+    DialogDescription: createPassthroughStub("DialogDescription"),
+    DialogFooter: createPassthroughStub("DialogFooter"),
+    DialogHeader: createPassthroughStub("DialogHeader"),
+    DialogTitle: createPassthroughStub("DialogTitle"),
+    DialogTrigger: createPassthroughStub("DialogTrigger"),
+  };
 });
 vi.mock("@/components/ui/dropdown-menu", async () => {
   const { createPassthroughStub } = await import("./vueHostHarness");
@@ -82,6 +92,8 @@ vi.mock("@/composables/useCellDetailEditor", () => ({ useCellDetailEditor: () =>
 vi.mock("@/composables/useTheme", () => ({ useTheme: () => ({ isDark: { value: false }, themePalette: { value: {} } }) }));
 vi.mock("@/stores/settingsStore", () => ({ useSettingsStore: () => ({ editorSettings: { cellDetailJsonFormatted: true, theme: "default", fontSize: 13, fontFamily: "monospace" }, updateEditorSettings: mocks.updateSettings }) }));
 vi.mock("@/lib/dataGrid/geometryPreview", () => ({ isHexGeometry: () => false, renderWktOnCanvas: mocks.renderWkt }));
+vi.mock("@/lib/common/clipboard", () => ({ copyToClipboard: mocks.copyToClipboard }));
+vi.mock("@/composables/useToast", () => ({ useToast: () => ({ toast: mocks.toast }) }));
 vi.mock("@/composables/useDataGridCellDetail", async () => {
   const { ref } = await import("vue");
   return {
@@ -106,6 +118,8 @@ import DataGridSearchBar from "@/components/grid/DataGridSearchBar.vue";
 const dataGridSource = readFileSync("apps/desktop/src/components/grid/DataGrid.vue", "utf8");
 const dataGridCellDetailEditSource = readFileSync("apps/desktop/src/composables/useDataGridCellDetailEdit.ts", "utf8");
 const cellDetailPanelSource = readFileSync("apps/desktop/src/components/grid/DataGridCellDetailPanel.vue", "utf8");
+const cellDetailDialogSource = readFileSync("apps/desktop/src/components/grid/DataGridCellDetailDialog.vue", "utf8");
+const binaryTextPreviewSource = readFileSync("apps/desktop/src/components/grid/DataGridCellDetailTextPreview.vue", "utf8");
 const cellDetailHeaderSource = readFileSync("apps/desktop/src/components/grid/DataGridCellDetailHeader.vue", "utf8");
 const globalsCss = readFileSync("apps/desktop/src/styles/globals.css", "utf8");
 
@@ -1540,6 +1554,164 @@ describe("cell detail surfaces", () => {
     expect(hostText(panel.root)).toContain("0x89504e470d0a1a0a");
   });
 
+  // issue #9505：GaussDB（ZenithDriver）的 BLOB 已经以 `0x<hex>` 到达前端，缺的是详情里显式、只读的文本查看入口。
+  it("offers an explicit read-only binary text preview in the dialog and the panel", () => {
+    const blobDetail = detail({
+      type: "BLOB",
+      value: "0x5b5b68656164657273203d207b7d",
+      rawValue: "0x5b5b68656164657273203d207b7d",
+      rawValuePreview: "0x5b5b68656164657273203d207b7d",
+      displayValue: "BLOB [14 bytes]",
+      displayValuePreview: "BLOB [14 bytes]",
+      formattedJson: "",
+    });
+    const dialog = mountComponent(DataGridCellDetailDialog, {
+      open: true,
+      detail: blobDetail,
+      typeColorClass: () => "",
+      openImagePreview: vi.fn(),
+      copyText: vi.fn(),
+      canDownloadBinaryValue: () => true,
+      downloadBinaryValue: vi.fn(),
+      canImportBinaryValue: () => false,
+      importBinaryValue: vi.fn(),
+      databaseType: "gaussdb",
+    });
+    const panel = mountComponent(DataGridCellDetailPanel, {
+      detail: blobDetail,
+      panelIsBottom: true,
+      metadataCollapsed: false,
+      valueFillsHeight: false,
+      editing: false,
+      sideJsonView: false,
+      showCompactJson: false,
+      canCompactJson: false,
+      typeColorClass: () => "",
+      canDownloadBinaryValue: () => true,
+      downloadBinaryValue: vi.fn(),
+      canImportBinaryValue: () => false,
+      importBinaryValue: vi.fn(),
+      openImagePreview: vi.fn(),
+      canCopySqlCondition: () => true,
+      databaseType: "gaussdb",
+    });
+
+    for (const mounted of [dialog, panel]) {
+      // canonical 值仍是 0x 十六进制，解码文本只出现在只读预览里。
+      expect(hostText(mounted.root)).toContain("0x5b5b68656164657273203d207b7d");
+      expect(hostText(mounted.root)).toContain("grid.binaryTextPreview");
+      // binary 列不再渲染 timestamp/radix 这类对 hex 无意义的文本转换。
+      expect(findAll(mounted.root, (node) => node.props["data-stub"] === "DataGridValueTransform")).toHaveLength(0);
+      expect(findOne(mounted.root, (node) => node.type === "textarea").value).toBe("[[headers = {}");
+    }
+  });
+
+  it("re-decodes the binary text preview with GBK only after the user picks it", async () => {
+    const panel = mountComponent(DataGridCellDetailPanel, {
+      detail: detail({ type: "BLOB", value: "0xd6d0cec4", rawValue: "0xd6d0cec4", rawValuePreview: "0xd6d0cec4", displayValue: "BLOB [4 bytes]", displayValuePreview: "BLOB [4 bytes]", formattedJson: "" }),
+      panelIsBottom: true,
+      metadataCollapsed: false,
+      valueFillsHeight: false,
+      editing: false,
+      sideJsonView: false,
+      showCompactJson: false,
+      canCompactJson: false,
+      typeColorClass: () => "",
+      canDownloadBinaryValue: () => true,
+      downloadBinaryValue: vi.fn(),
+      canImportBinaryValue: () => false,
+      importBinaryValue: vi.fn(),
+      openImagePreview: vi.fn(),
+      canCopySqlCondition: () => true,
+      databaseType: "gaussdb",
+    });
+
+    // 默认 UTF-8：GBK 字节严格解码失败时给出失败提示，而不是替换字符。
+    expect(hostText(panel.root)).toContain("grid.binaryTextPreviewErrors.undecodable");
+    dispatch(
+      findOne(panel.root, (node) => node.type === "button" && hostText(node).trim() === "grid.binaryTextPreviewEncodings.gbk"),
+      "click",
+    );
+    await nextTick();
+
+    expect(hostText(panel.root)).not.toContain("grid.binaryTextPreviewErrors.undecodable");
+    expect(findOne(panel.root, (node) => node.type === "textarea").value).toBe("中文");
+  });
+
+  it("keeps the value transform entry for non-binary detail cells", () => {
+    const panel = mountComponent(DataGridCellDetailPanel, {
+      detail: detail({ type: "VARCHAR(32)", value: "hello", rawValue: "hello", rawValuePreview: "hello", displayValue: "hello", displayValuePreview: "hello", formattedJson: "" }),
+      panelIsBottom: true,
+      metadataCollapsed: false,
+      valueFillsHeight: false,
+      editing: false,
+      sideJsonView: false,
+      showCompactJson: false,
+      canCompactJson: false,
+      typeColorClass: () => "",
+      canDownloadBinaryValue: () => false,
+      downloadBinaryValue: vi.fn(),
+      canImportBinaryValue: () => false,
+      importBinaryValue: vi.fn(),
+      openImagePreview: vi.fn(),
+      canCopySqlCondition: () => true,
+      databaseType: "mysql",
+    });
+
+    expect(findAll(panel.root, (node) => node.props["data-stub"] === "DataGridValueTransform")).toHaveLength(1);
+    expect(hostText(panel.root)).not.toContain("grid.binaryTextPreviewTitle");
+    expect(findAll(panel.root, (node) => node.type === "textarea")).toHaveLength(0);
+  });
+
+  it("keeps the binary text preview out of the copy-back and edit paths", async () => {
+    const copyValue = vi.fn();
+    const startEdit = vi.fn();
+    const panel = mountComponent(DataGridCellDetailPanel, {
+      detail: detail({ type: "BLOB", value: "0x48656c6c6f", rawValue: "0x48656c6c6f", rawValuePreview: "0x48656c6c6f", displayValue: "BLOB [5 bytes]", displayValuePreview: "BLOB [5 bytes]", formattedJson: "" }),
+      panelIsBottom: true,
+      metadataCollapsed: false,
+      valueFillsHeight: false,
+      editing: false,
+      sideJsonView: false,
+      showCompactJson: false,
+      canCompactJson: false,
+      typeColorClass: () => "",
+      canDownloadBinaryValue: () => true,
+      downloadBinaryValue: vi.fn(),
+      canImportBinaryValue: () => false,
+      importBinaryValue: vi.fn(),
+      openImagePreview: vi.fn(),
+      canCopySqlCondition: () => true,
+      databaseType: "gaussdb",
+      onCopyValue: copyValue,
+      onStartEdit: startEdit,
+    });
+
+    dispatch(
+      findOne(panel.root, (node) => node.type === "button" && hostText(node).trim() === "grid.binaryTextPreviewCopy"),
+      "click",
+    );
+    await nextTick();
+
+    expect(mocks.copyToClipboard).toHaveBeenCalledWith("Hello");
+    expect(mocks.toast).toHaveBeenCalledWith("grid.cellValueCopied", 2000);
+    // 预览只读：不触发栅格复制/编辑，details 预览仍展示未修改的 canonical hex。
+    expect(copyValue).not.toHaveBeenCalled();
+    expect(startEdit).not.toHaveBeenCalled();
+    expect(hostText(panel.root)).toContain("0x48656c6c6f");
+    expect(findOne(panel.root, (node) => node.type === "textarea").value).toBe("Hello");
+  });
+
+  it("keeps the binary text preview component strictly read-only and shared by both surfaces", () => {
+    expect(binaryTextPreviewSource).toContain("binaryCellTextPreview(props.value");
+    // 不发出任何编辑/提交事件，也不给 detail.value / rawValue 赋值。
+    expect(binaryTextPreviewSource).not.toContain("defineEmits");
+    expect(binaryTextPreviewSource).not.toMatch(/(?:props|detail)\.(?:value|rawValue)\s*=/);
+    expect(cellDetailDialogSource).toMatch(/<DataGridCellDetailTextPreview\s+v-if="open && isBinaryCellColumnType\(detail\.type\)"/);
+    // Panel 与下载菜单同一道闸门：编辑中不对草稿做只读文本预览。
+    expect(cellDetailPanelSource).toMatch(/<DataGridCellDetailTextPreview\s+v-if="!editing && isBinaryCellColumnType\(detail\.type\)"/);
+  });
+
   it("copies the presented value, emits edit, closes, and replaces the JSON result", async () => {
     const copyText = vi.fn();
     const edit = vi.fn();
diff --git a/apps/desktop/src/i18n/locales/az.ts b/apps/desktop/src/i18n/locales/az.ts
index b5358c7374..5bb9e974b4 100644
--- a/apps/desktop/src/i18n/locales/az.ts
+++ b/apps/desktop/src/i18n/locales/az.ts
@@ -2234,6 +2234,23 @@ export default withEnglishFallback({
       utf8: "Dekodlaşdırılmış mətn (UTF-8)",
       gbk: "Dekodlaşdırılmış mətn (GBK)",
     },
+    binaryTextPreview: "Mətn kimi bax",
+    binaryTextPreviewTitle: "İkili mətn önizləməsi",
+    binaryTextPreviewDescription: "0x onaltılıq baytları seçilmiş simvol dəsti ilə ciddi şəkildə dekodlaşdırır. Yalnız baxış üçündür; ilkin dəyər dəyişmir.",
+    binaryTextPreviewEncoding: "Simvol dəsti",
+    binaryTextPreviewEncodings: {
+      utf8: "UTF-8",
+      gbk: "GBK",
+    },
+    binaryTextPreviewByteCount: "{count} bayt",
+    binaryTextPreviewResult: "Dekodlaşdırılmış mətn",
+    binaryTextPreviewCopy: "Nəticəni kopyala",
+    binaryTextPreviewOriginalHint: "İlkin dəyər 0x onaltılıq kimi qalır; bu önizləmə hüceyrəni və ya verilənlər bazasını dəyişmir.",
+    binaryTextPreviewErrors: {
+      notBinary: "Bu dəyər tam ikili dəyər olmadığı üçün dekodlaşdırıla bilməz.",
+      incomplete: "Tam dəyər hələ yüklənməyib; natamam önizləməni dekodlaşdırmaq yanıltıcı olar.",
+      undecodable: "Ciddi dekodlaşdırma alınmadı: bu mətn deyil, real ikili məlumat (şəkil, arxiv və ya yanlış bayt ardıcıllığı) kimi görünür.",
+    },
     copyRowTsv: "Sətri kopyala (TSV)",
     copyColumnValues: "Sütunu kopyala (JSON)",
     copyColumnTsv: "Sütunu kopyala (TSV)",
diff --git a/apps/desktop/src/i18n/locales/en.ts b/apps/desktop/src/i18n/locales/en.ts
index 2250f11d40..494636ff4d 100644
--- a/apps/desktop/src/i18n/locales/en.ts
+++ b/apps/desktop/src/i18n/locales/en.ts
@@ -2394,6 +2394,23 @@ export default {
       utf8: "Decoded text (UTF-8)",
       gbk: "Decoded text (GBK)",
     },
+    binaryTextPreview: "View as text",
+    binaryTextPreviewTitle: "Binary text preview",
+    binaryTextPreviewDescription: "Strictly decodes the 0x hex bytes with the selected charset. Read-only preview; the original value is not modified.",
+    binaryTextPreviewEncoding: "Charset",
+    binaryTextPreviewEncodings: {
+      utf8: "UTF-8",
+      gbk: "GBK",
+    },
+    binaryTextPreviewByteCount: "{count} bytes",
+    binaryTextPreviewResult: "Decoded text",
+    binaryTextPreviewCopy: "Copy result",
+    binaryTextPreviewOriginalHint: "The original value stays as 0x hex; this preview does not modify the cell or the database.",
+    binaryTextPreviewErrors: {
+      notBinary: "This value is not a complete binary value, so it cannot be decoded.",
+      incomplete: "The full value has not been loaded yet; decoding an incomplete preview would be misleading.",
+      undecodable: "Strict decoding failed: this looks like real binary data (image, archive or invalid byte sequence), not text.",
+    },
     copyRowTsv: "Copy Row (TSV)",
     copyColumnValues: "Copy Column (JSON)",
     copyColumnTsv: "Copy Column (TSV)",
diff --git a/apps/desktop/src/i18n/locales/es.ts b/apps/desktop/src/i18n/locales/es.ts
index 089783a6d5..e692ab87e7 100644
--- a/apps/desktop/src/i18n/locales/es.ts
+++ b/apps/desktop/src/i18n/locales/es.ts
@@ -2222,6 +2222,23 @@ export default withEnglishFallback({
       utf8: "Texto decodificado (UTF-8)",
       gbk: "Texto decodificado (GBK)",
     },
+    binaryTextPreview: "Ver como texto",
+    binaryTextPreviewTitle: "Vista de texto binaria",
+    binaryTextPreviewDescription: "Decodifica de forma estricta los bytes hexadecimales 0x con el juego de caracteres elegido. Solo lectura; el valor original no cambia.",
+    binaryTextPreviewEncoding: "Juego de caracteres",
+    binaryTextPreviewEncodings: {
+      utf8: "UTF-8",
+      gbk: "GBK",
+    },
+    binaryTextPreviewByteCount: "{count} bytes",
+    binaryTextPreviewResult: "Texto decodificado",
+    binaryTextPreviewCopy: "Copiar resultado",
+    binaryTextPreviewOriginalHint: "El valor original se mantiene en hexadecimal 0x; esta vista previa no modifica la celda ni la base de datos.",
+    binaryTextPreviewErrors: {
+      notBinary: "Este valor no es un binario completo, por lo que no se puede decodificar.",
+      incomplete: "El valor completo aún no se ha cargado; decodificar una vista parcial sería engañoso.",
+      undecodable: "La decodificación estricta falló: parece un dato binario real (imagen, archivo comprimido o secuencia de bytes no válida), no texto.",
+    },
     copyRowTsv: "Copiar fila (TSV)",
     copyColumnValues: "Copiar columna (JSON)",
     copyColumnTsv: "Copiar columna (TSV)",
diff --git a/apps/desktop/src/i18n/locales/it.ts b/apps/desktop/src/i18n/locales/it.ts
index 88cb9aea7f..8b3dc4dd5a 100644
--- a/apps/desktop/src/i18n/locales/it.ts
+++ b/apps/desktop/src/i18n/locales/it.ts
@@ -2220,6 +2220,23 @@ export default withEnglishFallback({
       utf8: "Testo decodificato (UTF-8)",
       gbk: "Testo decodificato (GBK)",
     },
+    binaryTextPreview: "Visualizza come testo",
+    binaryTextPreviewTitle: "Anteprima testo binaria",
+    binaryTextPreviewDescription: "Decodifica in modo rigoroso i byte esadecimali 0x con il set di caratteri scelto. Solo lettura; il valore originale non viene modificato.",
+    binaryTextPreviewEncoding: "Set di caratteri",
+    binaryTextPreviewEncodings: {
+      utf8: "UTF-8",
+      gbk: "GBK",
+    },
+    binaryTextPreviewByteCount: "{count} byte",
+    binaryTextPreviewResult: "Testo decodificato",
+    binaryTextPreviewCopy: "Copia risultato",
+    binaryTextPreviewOriginalHint: "Il valore originale resta in esadecimale 0x; questa anteprima non modifica la cella né il database.",
+    binaryTextPreviewErrors: {
+      notBinary: "Questo valore non è un binario completo, quindi non può essere decodificato.",
+      incomplete: "Il valore completo non è ancora stato caricato; decodificare un'anteprima parziale sarebbe fuorviante.",
+      undecodable: "Decodifica rigorosa non riuscita: sembra un dato binario reale (immagine, archivio o sequenza di byte non valida), non testo.",
+    },
     copyRowTsv: "Copia Riga (TSV)",
     copyColumnValues: "Copia Colonna (JSON)",
     copyColumnTsv: "Copia Colonna (TSV)",
diff --git a/apps/desktop/src/i18n/locales/ja.ts b/apps/desktop/src/i18n/locales/ja.ts
index 16fd12d3cc..251808d39f 100644
--- a/apps/desktop/src/i18n/locales/ja.ts
+++ b/apps/desktop/src/i18n/locales/ja.ts
@@ -2232,6 +2232,23 @@ export default withEnglishFallback({
       utf8: "デコード済みテキスト (UTF-8)",
       gbk: "デコード済みテキスト (GBK)",
     },
+    binaryTextPreview: "テキストとして表示",
+    binaryTextPreviewTitle: "バイナリのテキストプレビュー",
+    binaryTextPreviewDescription: "選択した文字コードで 0x の 16 進数バイトを厳密にデコードします。表示専用で、元の値は変更されません。",
+    binaryTextPreviewEncoding: "文字コード",
+    binaryTextPreviewEncodings: {
+      utf8: "UTF-8",
+      gbk: "GBK",
+    },
+    binaryTextPreviewByteCount: "{count} バイト",
+    binaryTextPreviewResult: "デコード結果",
+    binaryTextPreviewCopy: "結果をコピー",
+    binaryTextPreviewOriginalHint: "元の値は 0x の 16 進数のまま保持され、このプレビューでセルやデータベースは変更されません。",
+    binaryTextPreviewErrors: {
+      notBinary: "この値は完全なバイナリではないため、デコードできません。",
+      incomplete: "完全な値がまだ読み込まれていないため、不完全なプレビューをデコードすると誤解を招きます。",
+      undecodable: "厳密なデコードに失敗しました。画像・アーカイブ・不正なバイト列など、テキストではないバイナリデータの可能性があります。",
+    },
     copyRowTsv: "行をコピー (TSV)",
     copyColumnValues: "列をコピー (JSON)",
     copyColumnTsv: "列をコピー (TSV)",
diff --git a/apps/desktop/src/i18n/locales/ko.ts b/apps/desktop/src/i18n/locales/ko.ts
index dbb7dfe9ca..62404c0385 100644
--- a/apps/desktop/src/i18n/locales/ko.ts
+++ b/apps/desktop/src/i18n/locales/ko.ts
@@ -2215,6 +2215,23 @@ export default withEnglishFallback({
       utf8: "디코딩된 텍스트 (UTF-8)",
       gbk: "디코딩된 텍스트 (GBK)",
     },
+    binaryTextPreview: "텍스트로 보기",
+    binaryTextPreviewTitle: "바이너리 텍스트 미리보기",
+    binaryTextPreviewDescription: "선택한 문자 집합으로 0x 16진수 바이트를 엄격하게 디코딩합니다. 읽기 전용이며 원본 값은 변경되지 않습니다.",
+    binaryTextPreviewEncoding: "문자 집합",
+    binaryTextPreviewEncodings: {
+      utf8: "UTF-8",
+      gbk: "GBK",
+    },
+    binaryTextPreviewByteCount: "{count}바이트",
+    binaryTextPreviewResult: "디코딩 결과",
+    binaryTextPreviewCopy: "결과 복사",
+    binaryTextPreviewOriginalHint: "원본 값은 0x 16진수로 유지되며, 이 미리보기는 셀이나 데이터베이스를 변경하지 않습니다.",
+    binaryTextPreviewErrors: {
+      notBinary: "이 값은 완전한 바이너리 값이 아니어서 디코딩할 수 없습니다.",
+      incomplete: "전체 값이 아직 로드되지 않았습니다. 불완전한 미리보기를 디코딩하면 오해를 줄 수 있습니다.",
+      undecodable: "엄격한 디코딩에 실패했습니다. 이미지, 압축 파일, 잘못된 바이트열 등 실제 바이너리 데이터일 수 있습니다.",
+    },
     copyRowTsv: "행 복사 (TSV)",
     copyColumnValues: "컬럼 복사 (JSON)",
     copyColumnTsv: "컬럼 복사 (TSV)",
diff --git a/apps/desktop/src/i18n/locales/pt-BR.ts b/apps/desktop/src/i18n/locales/pt-BR.ts
index 1516f8b705..3de65eefc3 100644
--- a/apps/desktop/src/i18n/locales/pt-BR.ts
+++ b/apps/desktop/src/i18n/locales/pt-BR.ts
@@ -2222,6 +2222,23 @@ export default withEnglishFallback({
       utf8: "Texto decodificado (UTF-8)",
       gbk: "Texto decodificado (GBK)",
     },
+    binaryTextPreview: "Ver como texto",
+    binaryTextPreviewTitle: "Pré-visualização de texto binário",
+    binaryTextPreviewDescription: "Decodifica estritamente os bytes hexadecimais 0x com o conjunto de caracteres escolhido. Somente leitura; o valor original não é alterado.",
+    binaryTextPreviewEncoding: "Conjunto de caracteres",
+    binaryTextPreviewEncodings: {
+      utf8: "UTF-8",
+      gbk: "GBK",
+    },
+    binaryTextPreviewByteCount: "{count} bytes",
+    binaryTextPreviewResult: "Texto decodificado",
+    binaryTextPreviewCopy: "Copiar resultado",
+    binaryTextPreviewOriginalHint: "O valor original permanece em hexadecimal 0x; esta pré-visualização não altera a célula nem o banco de dados.",
+    binaryTextPreviewErrors: {
+      notBinary: "Este valor não é um binário completo, então não pode ser decodificado.",
+      incomplete: "O valor completo ainda não foi carregado; decodificar uma pré-visualização incompleta seria enganoso.",
+      undecodable: "A decodificação estrita falhou: parece um dado binário real (imagem, arquivo compactado ou sequência de bytes inválida), não texto.",
+    },
     copyRowTsv: "Copiar Linha (TSV)",
     copyColumnValues: "Copiar Coluna (JSON)",
     copyColumnTsv: "Copiar Coluna (TSV)",
diff --git a/apps/desktop/src/i18n/locales/tr.ts b/apps/desktop/src/i18n/locales/tr.ts
index 88ee39932c..4aaa6d8658 100644
--- a/apps/desktop/src/i18n/locales/tr.ts
+++ b/apps/desktop/src/i18n/locales/tr.ts
@@ -2229,6 +2229,23 @@ export default withEnglishFallback({
       utf8: "Çözülmüş metin (UTF-8)",
       gbk: "Çözülmüş metin (GBK)",
     },
+    binaryTextPreview: "Metin olarak görüntüle",
+    binaryTextPreviewTitle: "İkili metin önizlemesi",
+    binaryTextPreviewDescription: "0x onaltılık baytları seçilen karakter kümesiyle katı biçimde çözer. Salt okunur; özgün değer değişmez.",
+    binaryTextPreviewEncoding: "Karakter kümesi",
+    binaryTextPreviewEncodings: {
+      utf8: "UTF-8",
+      gbk: "GBK",
+    },
+    binaryTextPreviewByteCount: "{count} bayt",
+    binaryTextPreviewResult: "Çözülen metin",
+    binaryTextPreviewCopy: "Sonucu kopyala",
+    binaryTextPreviewOriginalHint: "Özgün değer 0x onaltılık biçiminde kalır; bu önizleme hücreyi veya veritabanını değiştirmez.",
+    binaryTextPreviewErrors: {
+      notBinary: "Bu değer tam bir ikili değer olmadığı için çözülemez.",
+      incomplete: "Tam değer henüz yüklenmedi; eksik bir önizlemeyi çözmek yanıltıcı olur.",
+      undecodable: "Katı çözme başarısız oldu: bu metin değil, gerçek ikili veri (görsel, arşiv veya geçersiz bayt dizisi) gibi görünüyor.",
+    },
     copyRowTsv: "Satırı Kopyala (TSV)",
     copyColumnValues: "Sütunu Kopyala (JSON)",
     copyColumnTsv: "Sütunu Kopyala (TSV)",
diff --git a/apps/desktop/src/i18n/locales/zh-CN.ts b/apps/desktop/src/i18n/locales/zh-CN.ts
index f6881ec132..da84395172 100644
--- a/apps/desktop/src/i18n/locales/zh-CN.ts
+++ b/apps/desktop/src/i18n/locales/zh-CN.ts
@@ -2309,6 +2309,23 @@ export default withEnglishFallback({
       utf8: "解码文本 (UTF-8)",
       gbk: "解码文本 (GBK)",
     },
+    binaryTextPreview: "以文本查看",
+    binaryTextPreviewTitle: "二进制文本预览",
+    binaryTextPreviewDescription: "按所选字符集严格解码 0x 十六进制内容，仅用于查看，不修改原值。",
+    binaryTextPreviewEncoding: "字符集",
+    binaryTextPreviewEncodings: {
+      utf8: "UTF-8",
+      gbk: "GBK",
+    },
+    binaryTextPreviewByteCount: "{count} 字节",
+    binaryTextPreviewResult: "解码结果",
+    binaryTextPreviewCopy: "复制结果",
+    binaryTextPreviewOriginalHint: "原始值仍以 0x 十六进制保存，本次预览不会修改单元格或数据库。",
+    binaryTextPreviewErrors: {
+      notBinary: "当前值不是完整的二进制内容，无法解码。",
+      incomplete: "完整值尚未加载，解码不完整的预览会产生误导。",
+      undecodable: "严格解码失败：该内容更像真实二进制数据（图片、压缩包或非法字节序列），不是文本。",
+    },
     copyRowTsv: "复制行 (TSV)",
     copyColumnValues: "复制列 (JSON)",
     copyColumnTsv: "复制列 (TSV)",
diff --git a/apps/desktop/src/i18n/locales/zh-TW.ts b/apps/desktop/src/i18n/locales/zh-TW.ts
index 584f8c8d03..eeb956a990 100644
--- a/apps/desktop/src/i18n/locales/zh-TW.ts
+++ b/apps/desktop/src/i18n/locales/zh-TW.ts
@@ -2228,6 +2228,23 @@ export default withEnglishFallback({
       utf8: "文字編碼 (UTF-8)",
       gbk: "文字編碼 (GBK)",
     },
+    binaryTextPreview: "以文字檢視",
+    binaryTextPreviewTitle: "二進位文字預覽",
+    binaryTextPreviewDescription: "依所選字元集嚴格解碼 0x 十六進位內容，僅供檢視，不修改原值。",
+    binaryTextPreviewEncoding: "字元集",
+    binaryTextPreviewEncodings: {
+      utf8: "UTF-8",
+      gbk: "GBK",
+    },
+    binaryTextPreviewByteCount: "{count} 位元組",
+    binaryTextPreviewResult: "解碼結果",
+    binaryTextPreviewCopy: "複製結果",
+    binaryTextPreviewOriginalHint: "原始值仍以 0x 十六進位保存，本次預覽不會修改儲存格或資料庫。",
+    binaryTextPreviewErrors: {
+      notBinary: "目前值不是完整的二進位內容，無法解碼。",
+      incomplete: "完整值尚未載入，解碼不完整的預覽會造成誤導。",
+      undecodable: "嚴格解碼失敗：此內容更像真實二進位資料（圖片、壓縮檔或非法位元組序列），不是文字。",
+    },
     copyRowTsv: "複製整筆 (TSV)",
     copyColumnValues: "複製欄 (JSON)",
     copyColumnTsv: "複製欄 (TSV)",
diff --git a/apps/desktop/src/lib/dataGrid/binaryCellDownload.ts b/apps/desktop/src/lib/dataGrid/binaryCellDownload.ts
index 93083d17fd..f747463cca 100644
--- a/apps/desktop/src/lib/dataGrid/binaryCellDownload.ts
+++ b/apps/desktop/src/lib/dataGrid/binaryCellDownload.ts
@@ -221,6 +221,51 @@ export function binaryCellUtf8Text(value: unknown, columnType?: string, database
   return binaryCellUtf8TextBytes(bytes, columnType);
 }
 
+/** 单元格详情里「以文本查看」可选的字符集。 */
+export type BinaryCellTextEncoding = "utf8" | "gbk";
+
+export const BINARY_CELL_TEXT_ENCODINGS: BinaryCellTextEncoding[] = ["utf8", "gbk"];
+
+/**
+ * 显式文本预览（「以文本查看」）的失败原因，调用方据此给出不同文案：
+ *
+ * - `notBinary`：值不是 binary canonical form（含 hex 已被截断、列类型非 binary 的情况）；
+ * - `incomplete`：大值预览闸门截断了原始值，bytes 不完整，继续解码会把残缺内容当成文本；
+ * - `undecodable`：bytes 完整，但严格解码失败（非法序列，或图片/压缩包等二进制的控制字符）。
+ */
+export type BinaryCellTextPreviewError = "notBinary" | "incomplete" | "undecodable";
+
+export type BinaryCellTextPreviewResult = { ok: true; text: string; encoding: BinaryCellTextEncoding; byteLength: number } | { ok: false; error: BinaryCellTextPreviewError };
+
+/**
+ * issue #9505：把 binary canonical value（`0x<hex>`）按用户显式选择的字符集解码成**只读**文本。
+ *
+ * 与「下载为 UTF-8/GBK」共用同一套 bytes primitive（{@link parseBinaryCellBytes} +
+ * `binaryPreviewBytes`），但刻意不复用 `binaryCellDownloadPayload` 的宽松 `TextDecoder`：
+ * 预览必须走严格解码（见 {@link binaryCellUtf8TextBytes} / {@link printableGbkText}），
+ * 否则图片头等真实二进制会被替换字符伪装成「正常文本」。
+ *
+ * 与 `binaryCellUtf8Text` 的区别是**不做数据库白名单**：MySQL BLOB 的自动文本预览只对 mysql
+ * 连接开启（显示/编辑语义需要一致），而这里由用户在单元格详情里显式点击，属于只读 presentation，
+ * 因此任何被 `isBinaryCellColumnType()` 识别的 binary 列（BLOB/TINYBLOB/MEDIUMBLOB/LONGBLOB、
+ * BINARY/VARBINARY、BYTEA、BYTES、IMAGE、RAW/LONG RAW…）都可查看，且不参与解码闸门之外的任何写回路径。
+ * 入口可见性完全复用 `isBinaryCellColumnType()`，本次不为未知类型名称放宽该闸门。
+ *
+ * 返回值只用于展示：原始 `0x<hex>`、`detail.value` / `rawValue`、编辑草稿和数据库 bytes 都不受影响。
+ */
+export function binaryCellTextPreview(value: unknown, encoding: BinaryCellTextEncoding, columnType?: string, databaseType?: DatabaseType, incomplete?: boolean): BinaryCellTextPreviewResult {
+  if (incomplete) return { ok: false, error: "incomplete" };
+  if (!isBinaryCellColumnType(columnType)) return { ok: false, error: "notBinary" };
+  // 大值闸门会把 `0x<hex>` 本身截成 `0x...`，此时可解析的前缀不是完整 bytes，不能拿去解码。
+  if (typeof value === "string" && TRUNCATED_HEX_VALUE_RE.test(value.trim())) return { ok: false, error: "notBinary" };
+  const bytes = parseBinaryCellBytes(value, columnType, databaseType);
+  if (!bytes) return { ok: false, error: "notBinary" };
+  const preview = binaryPreviewBytes(bytes, columnType);
+  const text = encoding === "gbk" ? printableGbkText(preview) : printableUtf8Text(preview);
+  if (text === null) return { ok: false, error: "undecodable" };
+  return { ok: true, text, encoding, byteLength: bytes.length };
+}
+
 // 复制到剪贴板时，把「文本型」MySQL VARBINARY 单元格还原成其原始字符串。
 // DBX 后端为保留任意 bytes，把该值统一序列化成 `0x<hex>`；前端只有在严格 UTF-8 解码、
 // 无控制字符且重新编码后与原 bytes 完全一致时，才把 payload（如 token）复制为文本；
diff --git a/packages/app-tests/binaryCellDownload.test.ts b/packages/app-tests/binaryCellDownload.test.ts
index ea5b322541..c73b30b759 100644
--- a/packages/app-tests/binaryCellDownload.test.ts
+++ b/packages/app-tests/binaryCellDownload.test.ts
@@ -8,6 +8,7 @@ import {
   binaryCellClipboardText,
   binaryCellDownloadFileName,
   binaryCellDownloadPayload,
+  binaryCellTextPreview,
   canDownloadBinaryCellValue,
   formatBinaryCellByteSize,
   isBinaryCellColumnType,
@@ -108,6 +109,83 @@ test("binaryCellUtf8Text only returns strict printable text", () => {
   assert.equal(binaryCellUtf8Text("0x4869", "varchar", "mysql"), null);
 });
 
+// issue #9505：GaussDB（ZenithDriver）的 BLOB 已经以 binary canonical form `0x<hex>` 到达前端，
+// 缺的是单元格详情里“显式、只读”的文本查看入口。此 helper 是通用 binary presentation 层，
+// 不参与 MySQL BLOB 的自动文本预览闸门，也不进入编辑/提交路径。
+function previewText(value: unknown, encoding: "utf8" | "gbk", columnType?: string, databaseType?: Parameters<typeof binaryCellTextPreview>[3], incomplete?: boolean): string | null {
+  const result = binaryCellTextPreview(value, encoding, columnType, databaseType, incomplete);
+  return result.ok ? result.text : null;
+}
+
+test("binaryCellTextPreview decodes explicit binary cells to strict UTF-8 text", () => {
+  assert.deepEqual(binaryCellTextPreview("0x48656c6c6f", "utf8", "BLOB"), { ok: true, text: "Hello", encoding: "utf8", byteLength: 5 });
+  // issue 复现值的前 14 字节：`[[headers = {}`。
+  assert.deepEqual(binaryCellTextPreview("0x5b5b68656164657273203d207b7d", "utf8", "BLOB", "gaussdb"), { ok: true, text: "[[headers = {}", encoding: "utf8", byteLength: 14 });
+  // 中文 UTF-8。
+  assert.equal(previewText("0xe4b8ade69687", "utf8", "BLOB"), "中文");
+  // 非 MySQL 连接同样可以显式查看：属于用户主动触发的只读 presentation。
+  assert.equal(previewText("0x48656c6c6f", "utf8", "BLOB"), "Hello");
+  assert.equal(previewText("0x48656c6c6f", "utf8", "BYTEA", "postgres"), "Hello");
+  assert.equal(previewText("0x48656c6c6f", "utf8", "RAW(2000)", "oracle"), "Hello");
+  assert.equal(previewText("0x48656c6c6f", "utf8", "LONG RAW", "oracle"), "Hello");
+  assert.equal(previewText("0x48656c6c6f", "utf8", "IMAGE", "sqlserver"), "Hello");
+  // 入口可见性完全复用 isBinaryCellColumnType()，本次不放宽该闸门。
+  for (const type of ["BLOB", "TINYBLOB", "MEDIUMBLOB", "LONGBLOB", "BINARY(8)", "VARBINARY(255)", "BYTEA", "RAW(2000)", "LONG RAW", "IMAGE", "bytes"]) {
+    assert.equal(isBinaryCellColumnType(type), true, type);
+    assert.equal(previewText("0x48656c6c6f", "utf8", type), "Hello", type);
+  }
+  // byte[] / Buffer 形态的 binary cell 同样支持。
+  assert.equal(previewText([72, 105], "utf8", "VARBINARY(2)"), "Hi");
+  assert.equal(previewText({ type: "Buffer", data: [72, 105] }, "utf8", "VARBINARY(2)"), "Hi");
+  // 定长 BINARY 的尾部填充 NUL 与网格预览一致地裁掉。
+  assert.equal(previewText("0x3135303031300000", "utf8", "BINARY(8)"), "150010");
+  // 与“下载为 UTF-8/GBK”共用同一套 bytes primitive。
+  assert.deepEqual(Array.from(parseBinaryCellBytes("0x48656c6c6f", "BLOB") ?? []), Array.from(binaryCellDownloadPayload("0x48656c6c6f", "binary", "BLOB").data as Uint8Array));
+});
+
+test("binaryCellTextPreview decodes GBK bytes when the user picks GBK", () => {
+  assert.equal(previewText("0xd6d0cec4", "gbk", "BLOB"), "中文");
+  assert.equal(previewText("0xd6d0cec4", "gbk", "BLOB", "gaussdb"), "中文");
+  // UTF-8 仍是默认选项：GBK 字节不会被静默替换字符冒充文本。
+  assert.deepEqual(binaryCellTextPreview("0xd6d0cec4", "utf8", "BLOB"), { ok: false, error: "undecodable" });
+});
+
+// 真实二进制（图片头、非法序列、控制字节、GBK 私用区）必须显式失败，绝不能静默替换字符。
+test("binaryCellTextPreview refuses real binary instead of silently replacing characters", () => {
+  assert.deepEqual(binaryCellTextPreview("0x89504e470d0a1a0a", "utf8", "BLOB"), { ok: false, error: "undecodable" });
+  assert.deepEqual(binaryCellTextPreview("0xffd8ffe0", "utf8", "LONGBLOB"), { ok: false, error: "undecodable" });
+  assert.deepEqual(binaryCellTextPreview("0xfffe", "utf8", "BLOB"), { ok: false, error: "undecodable" });
+  assert.deepEqual(binaryCellTextPreview("0x0061", "utf8", "BLOB"), { ok: false, error: "undecodable" });
+  assert.deepEqual(binaryCellTextPreview("0x89504e470d0a1a0a", "gbk", "BLOB"), { ok: false, error: "undecodable" });
+  assert.deepEqual(binaryCellTextPreview("0xffff", "gbk", "BLOB"), { ok: false, error: "undecodable" });
+  assert.deepEqual(binaryCellTextPreview("0x0102", "gbk", "BLOB"), { ok: false, error: "undecodable" });
+});
+
+test("binaryCellTextPreview stays out of non-binary and incomplete cells", () => {
+  assert.deepEqual(binaryCellTextPreview("0x48656c6c6f", "utf8", "varchar(20)"), { ok: false, error: "notBinary" });
+  assert.deepEqual(binaryCellTextPreview("0x48656c6c6f", "utf8"), { ok: false, error: "notBinary" });
+  assert.deepEqual(binaryCellTextPreview("Hello", "utf8", "BLOB"), { ok: false, error: "notBinary" });
+  assert.deepEqual(binaryCellTextPreview(null, "utf8", "BLOB"), { ok: false, error: "notBinary" });
+  // 大值闸门把 `0x<hex>` 本身截成 `0x...` 时，前缀不是完整 bytes。
+  assert.deepEqual(binaryCellTextPreview("0xffd8ffe000104a46...", "utf8", "LONGBLOB"), { ok: false, error: "notBinary" });
+  // 后端返回的值本身不完整时不解码残缺 bytes。
+  assert.deepEqual(binaryCellTextPreview("0x48656c6c6f", "utf8", "BLOB", undefined, true), { ok: false, error: "incomplete" });
+  // TDengine 的 BINARY 裸 hex 是文本而不是 bytes。
+  assert.deepEqual(binaryCellTextPreview("66", "utf8", "BINARY(16)", "tdengine"), { ok: false, error: "notBinary" });
+});
+
+test("binaryCellTextPreview never mutates the canonical binary value", () => {
+  const canonical = "0x48656c6c6f";
+  assert.equal(previewText(canonical, "utf8", "BLOB"), "Hello");
+  assert.equal(canonical, "0x48656c6c6f");
+  const bytes = [0x48, 0x69];
+  assert.equal(previewText(bytes, "utf8", "VARBINARY(2)"), "Hi");
+  assert.deepEqual(bytes, [0x48, 0x69]);
+  const ascii = "0x534e2d4130303031";
+  assert.equal(previewText(ascii, "gbk", "VARBINARY(8)"), "SN-A0001");
+  assert.equal(ascii, "0x534e2d4130303031");
+});
+
 // 群反馈：MySQL varbinary 里以 GBK 写入的中文（Navicat 按连接字符集直接显示）。
 // UTF-8 严格解码失败后，仅 MySQL 的 binary/varbinary 在显示/复制路径回退严格 GBK；
 // BLOB 与编辑写回路径保持纯 UTF-8（与 coerceMysqlBlobTextValue 同闸门）。