docs.sheetjs.com/docz/docs/07-csf/07-features/10-visibility.md

title	sidebar_position
Sheet Visibility	10

File Format Support (click to show)

By default, all sheets in a workbook are "Visible". The standard "Hidden" state is controlled through the context menu in the sheet tab bar. The "Very Hidden" state is controlled through the "Visibility" property in the VBA editor.

Formats	Hidden	Very Hidden
XLSX/XLSM	✔	✔
XLSB	✔	✔
XLML	✔	✔
BIFF8 XLS	✔	✔
BIFF5 XLS	✔	✔

Excel enables hiding sheets in the lower tab bar. The sheet data is stored in the file but the UI does not readily make it available.

Standard "hidden" sheets are revealed in the "Unhide" menu.

Excel also has "very hidden" sheets which cannot be revealed in the menu. They are only accessible in the VB Editor!

Storage

The visibility setting is stored in the Hidden property of the corresponding metadata in the wb.Workbook.Sheets array

The recognized values are listed below:

Value	Definition	VB Editor "Visible" Property
0	Visible	-1 - xlSheetVisible
1	Hidden	0 - xlSheetHidden
2	Very Hidden	2 - xlSheetVeryHidden

If the respective Sheet entry does not exist or if the Hidden property is not set, the worksheet is visible.

Parsing

Since worksheet visibility is stored in the workbook, both the workbook object and the sheet name must be known to determine visibility setting.

function get_sheet_visibility(workbook, sheet_name) {
  // if the metadata does not exist for the sheet, the sheet is visible
  if(!workbook.Workbook) return 0;
  if(!workbook.Workbook.Sheets) return 0;

  var idx = workbook.SheetNames.indexOf(sheet_name);
  if(idx == -1) throw new Error(`Sheet ${sheet_name} missing from workbook`);

  var meta = workbook.Workbook.Sheets[idx];
  return meta && meta.Hidden || 0;
}

Typically the distinction between "hidden" and "very hidden" is not relevant for applications. The values were chosen to make logical negation work as expected:

function is_sheet_visible(workbook, sheet_name) {
  return !get_sheet_visibility(workbook, sheet_name); // true if visible
}

Writing

When assigning, the entire workbook metadata structure should be tested and constructed if necessary:

function set_sheet_visibility(workbook, sheet_name, Hidden) {
  var idx = workbook.SheetNames.indexOf(sheet_name);
  if(idx == -1) throw new Error(`Sheet ${sheet_name} missing from workbook`);

  // if the metadata does not exist for the sheet, create it
  if(!workbook.Workbook) workbook.Workbook = {};
  if(!workbook.Workbook.Sheets) workbook.Workbook.Sheets = [];
  if(!workbook.Workbook.Sheets[idx]) workbook.Workbook.Sheets[idx] = {};

  // set visibility
  workbook.Workbook.Sheets[idx].Hidden = Hidden;
}

Demo

This test file has three sheets:

• "Visible" is visible
• "Hidden" is hidden
• "VeryHidden" is very hidden

The live demo fetches the test file and displays visibility information.

function Visibility(props) {
  const [wb, setWB] = React.useState({SheetNames:[]});
  const [sheets, setSheets] = React.useState([]);
  const vis = [ "Visible", "Hidden", "Very Hidden" ];

  React.useEffect(() => { (async() => {
    const f = await fetch("/files/sheet_visibility.xlsx");
    const ab = await f.arrayBuffer();
    const wb = XLSX.read(ab);
    setWB(wb);
    /* State will be set to the `Sheets` property array */
    setSheets(wb.Workbook.Sheets);
  })(); }, []);

  return (<table>
    <thead><tr><th>Name</th><th>Value</th><th>Hidden</th></tr></thead>
    <tbody>{wb.SheetNames.map((n,i) => {
      const h = ((((wb||{}).Workbook||{}).Sheets||[])[i]||{}).Hidden||0;
      return ( <tr key={i}>
        <td>{n}</td>
        <td>{h} - {vis[h]}</td>
        <td>{!h ? "No" : "Yes"}</td>
      </tr> );
    })}</tbody></table>);
}

:::info pass

The live codeblock tests for visibility with:

const h = ((((wb||{}).Workbook||{}).Sheets||[])[i]||{}).Hidden||0;

With modern JS, this can be written as

const h = wb?.Workbook?.Sheets?.[i]?.Hidden||0;

:::