Is Microsoft Excel a secure spreadsheet editor?

Microsoft lets users manually encrypt and password-protect Excel workbooks, but this only provides end-to-end encryption if the file is shared outside Microsoft 365. When stored in OneDrive or SharePoint, Microsoft controls the encryption keys and can potentially access your data. Unlike Microsoft, Proton lets you and your team work on spreadsheets containing confidential information with the knowledge that no one, not even Proton, can gain access.

Is Proton Sheets safer than Microsoft Excel?

Proton Sheets provides greater security and privacy than Microsoft Excel because it uses end-to-end encryption. Excel does not offer true end-to-end encryption, meaning Microsoft can access your data for purposes including targeted advertising or to comply with legal or governmental requests. Proton’s end-to-end encryption also protects your data from unauthorized access, even in the event of a breach.

What is the best alternative to Microsoft Excel?

Proton Sheets is a trustworthy alternative to Microsoft Excel for those who value privacy and security for their business and client data. Unlike Microsoft Excel, our online spreadsheet software uses end-to-end encryption by default to protect your data and keep your information private, even when collaborating with others.

Why should I use encrypted spreadsheet software?

A private online document editor like Proton Sheets protects data from being shared with third parties or sold for profit. It lets you keep full ownership and control over your information, ensuring sensitive, professional, client, and customer information remains safe, secure, and confidential.

What to look for in an Excel alternative?

When looking for an alternative to Excel, it is important to find spreadsheet software that is compatible with your existing .xlsx, supports real-time collaboration, and features similar formulas and functions. Proton Sheets gives you all that, plus true privacy. It lets you upload and edit Excel workbooks while protecting them with end‑to‑end encryption, so neither Microsoft nor Proton can ever see your data. Proton Sheets also has a similar layout to Excel, so it is easy to transition your team to the new software without disrupting productivity.

The Excel alternative that protects your data

Protect confidential information with Proton Sheets, the end‑to‑end encrypted spreadsheet editor from Proton Drive.

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Proton Sheets vs Microsoft Excel

By foregoing advanced protections like end-to-end encryption by default, Microsoft Excel leaves your data vulnerable to breaches, surveillance, and third-party access.

Comparison of Proton Drive Google Drive Microsoft OneDrive and Dropbox
	Proton Sheets	Microsoft Excel
End-to-end encryption	Yes	No
Ad-free business model	Yes	No
Can’t scan or read your data	Yes	Yes
Formulas and functions	Yes	Yes
Data filtering and visualization	Yes	Yes
Easy sharing and real-time collaboration	Yes	Yes
Available on web, desktop, and mobile	Yes	Yes
Part of productivity suite including document editing, email, calendar	Yes	Yes

Unlike Microsoft, Proton lets you and your team work on spreadsheets containing confidential information with the knowledge that no one, not even Proton, can gain access.

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Make data-driven decisions, securely

Whether you’re navigating a tightly regulated field or handling ultra‑sensitive data, Proton Sheets lets your team explore and interpret information while keeping everything private.

Encrypt each cell

All Sheets are protected with end-to-end encryption — spreadsheet names, content, and calculations can only be seen by you and the people you choose.

Bring data to life

Transform raw numbers into clear charts, tables, and graphs that instantly surface insights and guide smarter decisions.

Simplify calculations

Leverage 200+ built‑in formulas and smart functions to crunch numbers, make forecasts, pull from large data sets, and manage reporting.

Control and manage access

Invite others via email to view or edit your sheets, stay in control with the option to revoke permissions at any moment.

Collaborate in real time

Edit the same sheet together with teammates or clients and changes appear instantly, so everyone stays synchronized.

Access anytime, anywhere

Open, modify, and share your online spreadsheets from any device, maintaining productivity whether you’re at a desk, remote, or on the move.

Import and export with ease

Upload existing Microsoft Excel spreadsheets (.xls, .xlsx, .xlsm) for editing and download your work in .xlsx, .csv, or .tsv formats.

Simplify compliance

Proton Drive is ISO 27001 certified, meeting the global standard for information security, and supports compliance with HIPAA, CCPA, and GDPR regulations.

All your files. One encrypted vault

Sheets is part of Proton Drive, our end-to-end encrypted cloud storage that lets you securely store and share spreadsheets, documents, and files.

See what Proton Drive can do for your business with a 14-day free trial.

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Start using a secure Microsoft Excel alternative

Shield your spreadsheets

Proton operates under Swiss privacy laws — some of the toughest in the world. Everything you do in Sheets stays securely beyond the reach of both EU and US jurisdictions.

Trust in transparency

Our code is open source and available for all to see. Third-party experts regularly inspect and verify Proton Drive so you can feel confident that everything works as we say it does.

Join the privacy revolution

Using Sheets in Proton Drive means joining a community dedicated to a future where privacy is the default. Together, we're building a more secure, private internet for everyone.

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Frequently asked questions

Is Microsoft Excel a secure spreadsheet editor?: Microsoft lets users manually encrypt and password-protect Excel workbooks, but this only provides end-to-end encryption if the file is shared outside Microsoft 365. When stored in OneDrive or SharePoint, Microsoft controls the encryption keys and can potentially access your data.
Unlike Microsoft, Proton lets you and your team work on spreadsheets containing confidential information with the knowledge that no one, not even Proton, can gain access.
Is Proton Sheets safer than Microsoft Excel?: Proton Sheets provides greater security and privacy than Microsoft Excel because it uses end-to-end encryption. Excel does not offer true end-to-end encryption, meaning Microsoft can access your data for purposes including targeted advertising or to comply with legal or governmental requests. Proton’s end-to-end encryption also protects your data from unauthorized access, even in the event of a breach.
What is the best alternative to Microsoft Excel?: Proton Sheets is a trustworthy alternative to Microsoft Excel for those who value privacy and security for their business and client data. Unlike Microsoft Excel, our online spreadsheet software uses end-to-end encryption by default to protect your data and keep your information private, even when collaborating with others.
Why should I use encrypted spreadsheet software?: A private online document editor like Proton Sheets protects data from being shared with third parties or sold for profit. It lets you keep full ownership and control over your information, ensuring sensitive, professional, client, and customer information remains safe, secure, and confidential.
What to look for in an Excel alternative?: When looking for an alternative to Excel, it is important to find spreadsheet software that is compatible with your existing .xlsx, supports real-time collaboration, and features similar formulas and functions.
Proton Sheets gives you all that, plus true privacy. It lets you upload and edit Excel workbooks while protecting them with end‑to‑end encryption, so neither Microsoft nor Proton can ever see your data. Proton Sheets also has a similar layout to Excel, so it is easy to transition your team to the new software without disrupting productivity.