Password protect Excel files online โ 4 modes, real AES-256, free.
The only Excel protection tool that ships every protection mode Microsoft Excel itself supports โ including the read-only recommendation that every other free tool quietly drops. Free, forever, no signup.
Built on enterprise-grade document processing technology โ the encryption strength you'd expect from $99/month commercial tools.
- ๐ 256-bit HTTPS
- โฑ 1-hour auto-delete
- โ GDPR compliant
- ๐ค No AI training on your data
- ๐ต We never log your password
โ Password loss = permanent data loss
We use real AES-256 encryption โ the same standard the U.S. government uses for top-secret documents. There is no backdoor. If you forget the file-open password, the file is unrecoverable. Save it before you click Apply.
Before you upload โ please confirm
You can only password-protect files you have the right to modify. Adding a password to a file you don't own โ for example, a corporate document you've been sent โ may violate your employer's data policy or local law.
Drag & drop your Excel file here, or click to browse
100 MB ยท .xlsx / .xlsm / .xls / .xlsb / .xltx / .xltm / .ods
Free Excel password protection โ every mode, every flag, every language
Most online Excel password tools either offer just one mode (file-open encryption only), wrap basic protection inside a $9/month paywall, or hard-cap your file at 2 MB. We don't. The four protection modes Microsoft Excel itself supports โ file-open AES-256, workbook-structure, per-sheet edit lock, and read-only recommendation โ are all here, free, with no signup, in eleven languages, on a 100 MB upload limit. We're transparent about which modes are real encryption and which are structural enforcement, and we never store your passwords.
Four protection modes โ pick one, mix all four
AES-256 file-open password
Workbook is encrypted at the OOXML container level. Without the password, the file cannot be opened in any version of Excel โ or any other tool. This is real cryptography (FIPS-140 approved), not just a 'lock' flag. Use it for confidential data.
Workbook structure protection
Prevents add / delete / hide / reorder / rename of sheets within the workbook. Cell contents stay readable. Useful for sharing a 'finished' workbook a colleague shouldn't restructure.
Per-sheet edit protection (14 granular flags)
Locks editing on the worksheets you choose. Excel exposes 14 allow-flags (select / format / sort / filter / insert / delete / pivot / object / scenario etc.) โ we surface every one of them. Per-sheet password optional.
Read-only recommendation
Excel suggests "open as read-only" when the recipient opens the file. They can still override. Pair it with a write-reservation password to require a password before saving back. The friendliest mode โ and the one most free tools skip.
Combine any or all four
These four modes are orthogonal. Common pattern: AES-256 (open the file) + per-sheet lock (edit specific tabs) + workbook structure (don't restructure). Toggle them independently in our UI.
Honest about which mode is real encryption
Only the file-open password is real encryption โ the other three are structural enforcement and can be removed by a determined attacker (including by free unprotect tools, ours included). Our UI labels each mode clearly so you pick the right level for your data.
How it works
- 1Confirm the Terms of Service in the hero (one checkbox โ you own the file or have permission).
- 2Drag-drop your .xlsx, .xlsm, .xls, .xlsb, or .ods file. 100 MB max. We inspect it and surface the sheet list.
- 3Pick one or more protection modes. For file-open password we show a strength meter and a generator; sheet protection lets you pick the specific worksheets.
- 4Click Apply. Sub-second processing. Download the protected file. Files auto-delete after 1 hour. We never store your password.
Why ExcelMaster's Excel Protect is different
Truly free โ every mode, every file
Aspose's free tier caps at 2 MB and skips the read-only mode. GroupDocs and Jumpshare ship one mode each. We ship all four modes, with a 100 MB free limit, and no per-day cap. No 'demo' watermark, no 'pay to unlock the result' dark pattern.
All four modes โ including the one everyone skips
Read-only recommendation + write-reservation password is the friendliest protection mode and the most common ask in business spreadsheets. It's also the one Aspose, GroupDocs, and Jumpshare quietly drop. We ship it, with both the soft hint and the optional write-reservation password.
Password strength meter + generator + show / hide
Industry standard for any password input โ and a feature missing from every Excel-protect tool we audited. We show a 5-segment strength bar, a one-click strong password generator, a show / hide eye, and a confirmation field. The basics, finally done.
Built on enterprise-grade infrastructure
The same class of OOXML processing technology trusted by Fortune 100 finance teams and government agencies for high-volume document workflows. Free for everyone.
11 languages, hreflang correct, locale-aware
Most competitor tools either ship English only or are visibly machine-translated. Every page on this tool โ including the FAQ, the warnings, and the password-strength feedback โ is hand-written by a human in eleven languages.
We never store your password
Your password is processed in-memory and never written to disk, logged, or transmitted to a third party. Your file is permanently deleted within 1 hour. We do not use uploaded data to train any AI model.
Frequently asked questions
What's the difference between the four protection modes?
File-open password is real AES-256 encryption โ the file cannot be opened without the password by any tool, period. Workbook structure protection prevents adding / removing / reordering sheets but cell contents stay readable. Per-sheet edit protection locks editing on individual worksheets (14 granular allow-flags). Read-only recommendation is a soft hint Excel shows on open โ recipients can override unless paired with a write-reservation password. Use file-open for confidentiality; the other three for structural and editing controls on shared workbooks.
Is the file-open password really uncrackable?
AES-256 is FIPS-140 approved and considered cryptographically secure for the foreseeable future โ the U.S. government classifies it as suitable for top-secret data. The practical attack surface is the password itself, not the cipher: a weak 6-character password can be brute-forced by commodity software in hours; a strong 16+ character password with mixed case, digits, and symbols is computationally infeasible to crack. Use the strength meter, save your password to a manager, and you're effectively safe.
Will my file work in older versions of Excel?
Yes. We use the OOXML standard encryption (ECMA-376 / ISO/IEC 29500), the same format Excel 2010 and later produce natively. Excel 2007 with Service Pack 2 also opens AES-256 files. For Excel 2003 and earlier you'd need to save back to .xls โ those files use the older, weaker RC4 encryption. We default to the modern AES-256 format.
Do you store my password anywhere?
No. Your password is processed in-memory only. It is never written to disk, never logged, never transmitted to a third party. The file is permanently deleted from our servers within 1 hour. The only thing we keep is anonymous metadata (file size, processing time, success / failure) for service-health monitoring.
What if I forget the password?
If it's a file-open AES-256 password, the file is permanently unrecoverable. Microsoft can't recover it. We can't recover it. There is no backdoor. The only options are (a) brute-force services like LostMyPass for short / weak passwords, or (b) accept the data loss. This is why we surface a hard warning before you encrypt and recommend saving the password to a manager. Sheet / workbook / read-only protection passwords are non-encryption hashes and can be removed by our Excel Unlock tool.
How big a file can I upload?
100 MB per file. Larger than every free competitor: Aspose (Free) caps at 2 MB; SodaPDF caps at 3 MB; GroupDocs (Free) at 50 MB; Jumpshare (Free) at 100 MB but with a 2-files-per-day cap (we have no such cap). Processing is roughly 200-1500 ms regardless of file size.
What file formats do you support?
.xlsx, .xlsm, .xltx, .xltm โ full AES-256 + structure + sheet + read-only support. .xls โ legacy binary format, supported with RC4 / older encryption. .xlsb โ supported. .ods โ supported with structure / sheet protection (LibreOffice's encryption is different from Excel's). For best security and compatibility, save your file as .xlsx before protecting.
Can I share a protected file by link?
Yes. The download URL we return uses an unguessable token; anyone you share the URL with can download the protected file. The protected file itself still requires your password to open. Tip: share the file URL and the password through different channels (e.g. email + Signal) to reduce interception risk.
Will macros / pivots / charts / conditional formatting be preserved?
Yes โ all OOXML content is preserved verbatim. We don't rewrite or reinterpret cell content; we only attach the encryption / protection metadata. Macros (.xlsm), pivot tables, charts, conditional formatting, named ranges, comments, data validation rules, and external links all survive intact.
Is this legal?
Yes. Adding a password to a file you own or have permission to modify is unambiguously legal in every jurisdiction. We require an explicit ToS checkbox confirming you have the right to modify the file. Removing protection from someone else's file is a different question (and is what our Excel Unlock tool addresses, with its own legal framing). This tool only adds protection โ it cannot remove it.
I want to protect 50 files with the same password โ is that supported?
Single-file protection is the current shipping mode. Batch protection with shared password is on the immediate roadmap (Sprint A.4). For the moment, the fastest workflow is the ExcelMaster Add-in's Ribbon button: pick a folder, set one password, and protect every workbook in place. The add-in is free.
Is there an installable version?
Yes โ ExcelMaster Add-in. It's our flagship Excel add-in (free) that adds an AI assistant for any spreadsheet task: formulas, pivots, charts, analysis. Password protection works inside Excel right from the Ribbon โ no upload required, batch protection supported. If you protect files often, the add-in is the better experience.