Proton launches encrypted spreadsheet tool Proton Sheets

Proton has officially launched Proton Sheets, a fully end-to-end encrypted spreadsheet editor, offering users a secure alternative to Google Sheets and Microsoft Excel.

The new tool expands Proton Workspace, which already includes Proton Docs and Proton Drive, and aims to protect sensitive business data from surveillance, tracking, and AI model training.

Proton is a Switzerland-based company known for its privacy-centric services, such as Proton Mail and Proton VPN. The introduction of Proton Sheets addresses growing concerns about the use of business data in AI pipelines, especially as Big Tech platforms embed AI assistants, such as Google’s Gemini, directly into productivity software.

Proton Sheets was developed by the same team behind Proton Drive, led by Anant Vijay Singh, Head of Product. Singh highlighted the risks of using mainstream tools that are increasingly leveraging user data for AI training, stating that the new tool aims to “reclaim data sovereignty” for businesses and individuals alike. According to Singh, “Every keystroke, every formula you enter can feed into their AI training pipelines. This is an unacceptable trade-off.”

Proton Sheets brings spreadsheet functionality to the privacy-first Proton ecosystem. Its end-to-end encryption ensures that only the user can access spreadsheet content, including metadata such as file names. This level of protection stands in contrast to competitors like Google and Microsoft, whose products are not encrypted by default and are subject to relatively loose US data protection laws.

A 2025 industry report cited by Proton found that 72% of North American businesses rely heavily on spreadsheets for tasks such as financial modeling, business intelligence, and planning. However, the growing integration of AI into these tools is raising alarms, especially when sensitive or proprietary data could be fed into machine learning systems without explicit user consent.

Key features of Proton Sheets include:

• End-to-end encryption of all spreadsheet contents and metadata, accessible only by the user.
• Data visualization and filtering capabilities for turning raw data into charts and graphs.
• Support for standard formulas and quick calculations, simplifying day-to-day number crunching.
• Real-time collaboration, allowing teams to work together with synced edits.
• Cross-device access, ensuring secure usability across desktops and mobile devices.
• Granular access control, enabling users to manage view/edit permissions and revoke access at any time.
• Secure import of CSV and XLS files, encrypting files upon upload.

With the addition of Proton Sheets, Proton Drive now offers a complete alternative to mainstream productivity suites, covering documents, cloud storage, spreadsheets, and collaboration.

Organizations should audit their current use of cloud-based spreadsheets and evaluate whether proprietary data is being stored in environments susceptible to AI-driven data harvesting. When handling sensitive financial or strategic information, consider using platforms with verifiable encryption standards and fully user-controlled access.