Privacy-first cloud providers: Proton Drive, Tresorit, and the tradeoffs

For most of cloud storage’s history, “cloud storage” and “end-to-end encrypted” were mutually exclusive. Dropbox, Google Drive, iCloud, and OneDrive all held your decryption keys, and the E2EE alternatives (Mega, SpiderOak, early Sync.com) were either sketchy or unusable.

That’s changed. Today, a handful of providers — Proton Drive, Tresorit, Sync.com, Filen, Standard Notes (for notes) — offer genuinely E2E encrypted storage with interfaces you can actually give to a non-technical family member. They are also not drop-in replacements for the big four, and the differences show up in specific places.

This article is a practical comparison. Who they are, what they guarantee, where they fall short, and when to pick one over a mainstream provider with a client-side encryption layer on top.

What “privacy-first” actually means

A privacy-first cloud provider commits to a specific property: they cannot, technically, read your files. The commitment is usually made in three places:

1. Key generation on-device. The encryption keys that protect your files are created on your computer or phone, and the private key never leaves your device in unencrypted form.
2. Ciphertext storage. What lives on the provider’s servers is encrypted with your key. Without that key, the server-side data is noise.
3. Documented and audited cryptography. The protocol is public, the implementations are often open-source, and independent security auditors have reviewed the setup.

These are not marketing claims you take on faith. Each of the providers below publishes a security whitepaper, and several have open-sourced their clients.

The providers, briefly

Proton Drive

• Based in: Switzerland.
• Company: Proton AG, which also runs ProtonMail, ProtonVPN, Proton Calendar, Proton Pass.
• Open source: Clients are open-source on GitHub.
• Pricing: Free tier up to 5 GB; paid starts around €4/month for 500 GB, or bundled with Proton’s other services in Proton Unlimited.
• Strengths: Integrated ecosystem (same account as Proton Mail/VPN/Pass), mature clients across platforms, strong Swiss data-protection jurisdiction, published protocol.
• Weaknesses: Desktop sync has historically lagged the polish of Dropbox. Sharing features are functional but less refined than Google Drive. Limited third-party-app ecosystem.

Tresorit

• Based in: Switzerland (founded in Hungary, now owned by Swiss Post).
• Company: Tresorit AG.
• Open source: Not open-source; has audited cryptography.
• Pricing: No meaningful free tier; business-oriented pricing from ~$11/user/month.
• Strengths: Very polished interface, strong team/business features, HIPAA-eligible, reliable sync, GDPR-native posture.
• Weaknesses: Expensive for individuals. Closed-source means you trust the audit rather than verify yourself.

Sync.com

• Based in: Canada.
• Company: Sync.com Inc.
• Open source: Not open-source; cryptography documented.
• Pricing: Free tier 5 GB; paid from ~$8/month for 2 TB.
• Strengths: Aggressively priced for the privacy-first category. Good desktop sync. Canadian jurisdiction is generally privacy-favorable.
• Weaknesses: Smaller team; less public cryptographic review than Proton. Some feature gaps relative to mainstream providers.

Standard Notes (notes only, not general files)

• Based in: USA.
• Open source: Yes, aggressively.
• Pricing: Free tier; paid from ~$10/month for extended features.
• Strengths: End-to-end encrypted notes with a clean writing interface, extensions for markdown, code, spreadsheets.
• Weaknesses: Notes, not general file storage. Included here because many readers use “cloud storage” as a synonym for “somewhere to keep writing”.

Filen

• Based in: Germany.
• Open source: Yes.
• Pricing: Free tier 10 GB; paid from ~€1/month for 100 GB.
• Strengths: Cheap, fully E2EE, open-source clients.
• Weaknesses: Smaller company, shorter track record. Less mature ecosystem.

The usability tax

Every privacy-first provider pays for its guarantees with specific usability losses. These aren’t defects; they’re the unavoidable consequence of the server not being able to read your files.

Slower first sync on a new device. The server holds ciphertext and cannot pre-compute thumbnails, indexes, or compressed previews for you. Your client has to download and process everything locally.

Weak or no server-side search. Mainstream providers search the full text of your documents; E2EE providers can only search what was indexed on your device. This often means fewer, less-fuzzy search results.

Thumbnail and preview gaps. Previews are generated client-side, which means they only exist for documents your current device has synced. Opening a rarely-used file over a slow connection takes longer.

Collaboration is more awkward. Sharing a document with someone who doesn’t have an account means re-encrypting keys for them, giving them a URL with the decryption key in the URL fragment, or forcing them to sign up. Real-time collaboration on a single document is rare or missing — the complexity is much higher than for plaintext-aware services.

Third-party app integrations are limited. Mainstream clouds have thousands of connected apps (via OAuth APIs) that read and write files. For E2EE clouds, an integration would need to handle encryption, which few do.

Higher prices per GB. On average, privacy-first services cost 1.5–3x what mainstream services charge.

These costs are not hidden; the honest privacy-first providers disclose them. The marketing challenge, if you’re choosing one, is to compare them on like-for-like features rather than just price per GB.

Where each fits

Use this as a decision frame:

You want E2EE for everything, simplicity, and already use ProtonMail: Proton Drive. The ecosystem effect is the main reason to pick it.

You’re a professional with regulated client data (health, legal, financial) and need team features: Tresorit. Worth the price for the HIPAA/GDPR posture and polish.

You want the cheapest credible E2EE storage with decent usability: Sync.com or Filen. Good for personal storage where price matters.

You want to write, not store files: Standard Notes for notes only.

You need collaboration on living documents: none of the above are great. Use a mainstream provider (with hardening turned on) for the collaborative work, and a privacy-first provider alongside it for archival storage of sensitive material.

The hybrid pattern

Most readers end up with a hybrid setup, and it’s a reasonable outcome:

• Mainstream provider (Google / Apple / Microsoft / Dropbox) for everyday work, collaboration, mobile photo backup, and files shared with people who won’t install anything new.
• Privacy-first provider or Cryptomator on top of the mainstream provider for the sensitive subset: tax records, medical documents, legal correspondence, intimate photos, work that hasn’t been published yet.

That two-tier approach gets you the ergonomics of the mainstream providers and the confidentiality guarantees of E2EE for the documents that warrant them. It is almost always the right answer for a reader who isn’t running a high-risk operation.

The alternative — putting everything into an E2EE provider — is a decision worth making deliberately, for readers with a threat model (journalists, activists, specific regulated professions) that justifies the usability cost. For everyone else, the hybrid is more livable and protects what actually matters.