Filen

Filen is a zero-knowledge encrypted cloud storage service founded in 2020 by a team of German cybersecurity enthusiasts in Recklinghausen, Germany. Built from the ground up with privacy as the core principle, Filen implements client-side end-to-end encryption that ensures your files are encrypted before they ever leave your device—making it technically impossible for Filen or anyone else to access your data.

What distinguishes Filen is its combination of genuine zero-knowledge architecture with developer-friendly features and generous pricing. Every file is individually encrypted with AES-GCM 256-bit encryption using keys derived from your password. The encryption happens entirely on your device, and your master key never leaves your control. This means Filen cannot access your files even if compelled by authorities—they simply don’t have the technical capability.

All Filen data is stored in Tier IV, ISO 27001-certified high-security data centers located exclusively in Germany. The company operates under German data protection law and full GDPR compliance, providing strong legal protections alongside the technical ones. Unlike many cloud providers, Filen has no US presence or data processing, keeping your files firmly under EU jurisdiction.

Filen offers a remarkably generous free tier: 10GB of fully encrypted storage with no restrictions on features or encryption quality. Paid plans start at just €1/month and include lifetime purchase options during promotions. All Filen applications are open source under the AGPL-3.0 license, and the company provides comprehensive APIs including TypeScript SDK, Go SDK, WebDAV support, and S3-compatible interfaces—a rare combination of privacy and developer accessibility.

Key Features

• Zero-Knowledge Encryption: AES-GCM 256-bit client-side encryption
• 10GB Free Tier: Generous free storage with full encryption
• Open Source Apps: All clients available under AGPL-3.0
• Developer APIs: TypeScript SDK, Go SDK, WebDAV, S3-compatible
• German Data Centers: Tier IV, ISO 27001-certified facilities
• No Speed Limits: Unlimited upload and download speeds
• File Versioning: Recover previous versions of files

Privacy Highlights

Filen’s zero-knowledge architecture means encryption keys are derived from your password and never transmitted to Filen’s servers. Files are encrypted individually before upload, and even file names and folder structures are encrypted. This design ensures that a data breach, rogue employee, or legal demand cannot expose your files because Filen genuinely cannot decrypt them.

The company solved a significant technical challenge by enabling WebDAV and S3 protocols to work with a fully encrypted backend through a locally hosted reverse proxy. This allows integration with existing tools while maintaining end-to-end encryption.

Privacy Breakdown

Data Residency (Score: 100)

Pros:

• All data in Tier IV ISO 27001-certified German data centers
• Full GDPR compliance
• No US data processing or storage
• German company under German jurisdiction

Cons:

• None identified

Confidence: High — verified through security whitepaper and company documentation.

Open Source (Score: 92)

Pros:

• All applications open source under AGPL-3.0
• Source code on GitHub for community audit
• Encryption implementation publicly verifiable
• Active development and community engagement

Cons:

• Server-side code not open source (common for cloud services)

Confidence: High — code available at github.com/FilenCloudDienworte.

Privacy Policy (Score: 90)

Pros:

• Zero-knowledge architecture prevents data access
• Clear privacy policy explaining data handling
• Minimal metadata collection
• GDPR rights fully supported

Cons:

• Basic account information (email, IP) collected
• Some metadata technically accessible for service operation

Confidence: High — policy and security whitepaper reviewed January 2026.

Trackers (Score: 88)

Pros:

• No advertising trackers
• No social media tracking
• Privacy-focused service design

Cons:

• Some analytics for service improvement
• Cookie usage for functionality

Confidence: Medium — based on privacy policy and website analysis.

Terms of Service (Score: 75)

Pros:

• User retains ownership of all data
• Clear data portability rights
• Transparent about service limitations

Cons:

• Standard SaaS liability limitations
• Account termination provisions
• Lifetime plans subject to company viability

Confidence: Medium — ToS reviewed January 2026.