Password Protect Excel

Password protect an Excel workbook online: encrypt XLSX files with AES-256 so Excel asks for a password to open them. Free, private, in your browser.

Files are processed in your browser and never uploaded.

How to password protect an Excel file

  1. Drop an .xlsx, .xlsm or .xlsb workbook onto the drop zone above, or click to choose it.
  2. Enter the Password that will be required to open the workbook.
  3. Click Protect workbook. Key derivation takes around a second while a progress indicator runs.
  4. Download the encrypted copy. A workbook called payroll-march.xlsx is saved as payroll-march-protected.xlsx.

The workbook is encrypted in your browser. Salary figures, customer lists and other sensitive data are never uploaded, and the password is not sent anywhere.

Password to open vs Protect Sheet and Protect Workbook

Excel offers several kinds of protection, and the names are easy to mix up. This tool sets the password to open, the same thing as File > Info > Protect Workbook > Encrypt with Password in Excel. Despite the button label, it is not the structure-locking "Protect Workbook" command on Excel's Review tab.

Excel featureData encrypted?What it stops
Encrypt with Password (this tool)YesOpening the file and reading any cell without the password
Protect SheetNoEditing locked cells, formatting or inserting rows on one sheet
Protect Workbook (structure)NoAdding, deleting, renaming, hiding or moving sheets

Protect Sheet and structure protection are designed to prevent accidental changes to formulas and layout. They do not hide anything: the values are stored in the file in readable form. A hidden sheet with salary data is still there for anyone who opens the workbook. When the goal is to keep numbers confidential, encrypt the whole file.

How the encryption works

The tool writes the ECMA-376 Agile Encryption format used by Excel 2010 and later and by LibreOffice. The complete workbook package, including every sheet, chart, pivot cache and, for .xlsm files, the macro project, is encrypted with AES-256 in CBC mode. The key is derived from your password using SHA-512 with 100,000 iterations, which makes guessing much slower, and an HMAC integrity check detects tampering.

The protected workbook opens with a password prompt in Excel 2010 and later, Microsoft 365, Excel for Mac and LibreOffice Calc. Google Sheets and many file previewers cannot open encrypted Office files, so plan for recipients to use a desktop spreadsheet application. Legacy .xls files are not supported; save them as .xlsx first.

Tips

  • Spreadsheets with personal data deserve a strong password. Generate one with the password generator and share it separately from the file.
  • Bring monthly sheets together with Merge Excel before protecting, so there is a single file and a single password to manage.
  • If recipients only need to see the figures, convert with Excel to PDF and lock the result with Protect PDF.
  • To remove the password later, use Unlock Excel.
Tip: Sheet protection and file encryption work well together. Encrypt the file to keep outsiders out, and use Protect Sheet inside Excel to stop colleagues who have the password from overwriting formulas by mistake.

Frequently asked questions

Can I get back into the workbook if I lose the password?

No. The tools on this site never crack or guess passwords, and AES-256 encrypted workbooks cannot be opened without the correct one. Keep an unencrypted copy somewhere safe or store the password in a password manager.

Can I protect several workbooks at once?

The tool encrypts one workbook at a time. Repeat the steps for each file, or merge related workbooks first so that one password covers them all.

Can I upload the protected file to Google Sheets?

Google Sheets does not open password-encrypted Excel files. Recipients who work in Google Sheets need an unprotected copy.

Does this also lock cells or sheets?

No. It only adds a password to open. Cell and sheet locking are set inside Excel with Protect Sheet.

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