Put a real password on a spreadsheet, or take one back off. Protected workbooks come back encrypted — Excel asks for the password before it shows a single cell — and you can have the password emailed to you so a strong one isn't a risky one.
There is no way to recover this password. We don't store it, and a workbook encrypted without it can't be opened by us, by Microsoft, or by anyone else. Write it down before you press the button.
has downloaded. Opening it in Excel now asks for your password.
has downloaded. It opens without a password now, so keep it somewhere that doesn't need one.
Upload a workbook, pick a password, and get the same workbook back encrypted. Anyone opening it — in Excel, LibreOffice, Numbers, Google Sheets — is asked for the password first, and without it there is nothing to read. Nothing inside the file changes: the encryption wraps the workbook exactly as it arrived.
Excel uses the word protect for several different things, and only one of them actually keeps data private.
If your reason for adding a password is that the file shouldn't be read by the wrong person, encryption is the only one of those that does the job.
Tools that rebuild a spreadsheet to change it tend to lose the parts they don't understand — pivot tables, charts, conditional formatting, data validation, macros. Encryption here doesn't parse the workbook at all. The original file's bytes are sealed inside an encrypted container, so what comes out after the password is entered is identical, feature for feature, to what went in.
The Remove a password tab does the same thing in reverse: give it a protected workbook and the password that opens it, and it hands back the file exactly as it was before it was encrypted — same sheets, same formulas, same formatting, no prompt. Useful when a file is moving somewhere already access-controlled, when the password has done its job, or when a workbook needs to be read by something that can't handle encryption — a script, an import job, Google Sheets.
It needs the correct password, and that is not a limitation to work around — it is the whole point. The file's contents are encrypted under a key derived from the password, so a wrong password doesn't produce partial or garbled data, it produces nothing at all. Nothing here recovers, cracks or bypasses a password, and repeated wrong guesses pause the tool for an hour.
No, and nor can anyone else. We never store it — it exists for the few seconds the encryption takes and is then gone. That is the point of real encryption, and it is why the reminder email exists.
It is a password sitting in an inbox in plain text, which is exactly as safe as your inbox and no safer. It's there because the alternative — people choosing a password weak enough to remember — is usually worse. Send it, save the password somewhere you trust, then delete the email. We keep no copy: the mail is written from memory as it's sent.
AES, using the ECMA-376 agile encryption scheme — the same standard Excel itself writes when you use File › Info › Protect Workbook › Encrypt with Password. The strength that's actually in your hands is the password: a short or common one is guessable however good the cipher is.
Yes. It's a standard encrypted workbook, so Excel, LibreOffice and Numbers all prompt for the password and open it. Google Sheets can't open encrypted files — that's a limitation of Sheets, not of the file.
Yes — switch this page to Remove a password, upload the file and give it the password it currently opens with. You can also do it in Excel: open the file, then File › Info › Protect Workbook › Encrypt with Password, clear the box, and save.
No — the upload is rejected rather than layering a second password over the first. Remove the existing one in Excel first, then upload it here.
No. Not "no, and here's a workaround" — there genuinely isn't one. The workbook's contents are encrypted with a key derived from the password, so without it there is no data to recover, and that is equally true for us, for Microsoft, and for anyone selling you a recovery tool. This is why the reminder email is offered at the point the password is set.
No. Encrypting sealed the original file rather than rewriting it, so removing the password unseals exactly those bytes — the result is identical to the workbook that went in, down to the last formula and cell format.
Processed for your session and deleted within the hour. Not kept, not shared, not used for anything else. Three workbooks a month without an account.