As of 1 Nov 2026, the panel rates Proton Drive 3/5 and Tresorit 3.5/5 in Cloud Storage & File Sharing. Weighted by what each judge cares about, 0 of the 6 judges pick Proton Drive and 5 pick Tresorit, 1 calls it a tie. Proton Drive scores higher on 3 of 7 criteria (European sovereignty, Encryption, key custody & recovery and Sync, clients & file access). Tresorit scores higher on 3 of 7 criteria (Sharing & external collaboration, Administration, audit & governance and Export, API & self-hosting). Provenance — Proton Drive: UK / wider Europe; Tresorit: UK / wider Europe. Ratings are the AI panel’s opinion, formed from public evidence: how scores are made.
Proton Drive holds the security bench: encryption and security averages 8.7 to 7.8, with five judges leaning its way and one tie, and sovereignty runs 8.0 to 7.0 on six leans — its verdict records a Swiss entity, self-owned data centres in Switzerland and Germany, and a published GDPR data processing agreement, with payment and support subprocessors such as Stripe and Zendesk processing in the United States under standard contractual clauses. Tresorit takes sharing and collaboration 8.8 to 5.8 and administration and governance 7.0 to 5.8 on six leans each, plus portability and integrations 4.8 to 4.0 on five leans with one tie. Sync and access, 5.8 to 5.7, and pricing transparency, level at 5.8, split one lean either way with four ties each. On weighted totals, five judges put Tresorit ahead; the architect scores both 6.1.
Choose Proton Drive if
You rank encryption and security first: five judges lean Proton Drive there, 8.7 to 7.8, and the verdict records contents, names and metadata encrypted on the device with keys never leaving it.
Your procurement wants a Swiss footing: the verdict records Proton AG contracted under Swiss law, self-owned data centres in Switzerland and Germany, and a published GDPR data processing agreement, and six judges lean Proton Drive on sovereignty, 8.0 to 7.0.
You need long recovery windows: the verdict records ten years of version recovery on paid plans.
You want code you can inspect: the verdict records open-source apps with published Securitum audits and a bug bounty reaching USD 100,000.
Choose Tresorit if
Your work runs through external sharing: six judges lean Tresorit on sharing and collaboration, 8.8 to 5.8, on encrypted links with password, expiry, disabled download and print, watermarks, and file requests for recipients without an account.
You administer a team: six judges lean Tresorit on administration and governance, 7.0 to 5.8.
You weight portability and integrations: five judges lean Tresorit there, 4.8 to 4.0, with one tie.
Your team edits documents in place: the verdict records zero-knowledge office editing on Collabora.
Read this comparison as one judge. Each weighs the same scores by what they care about.
The Skeptic
Has seen "end-to-end encrypted" on a service that switches it off for shared folders, "hosted in Germany" on storage whose accounts and support run from the US, and "lifetime" plans from a company two years old. Reads that a product is "GDPR-compliant" and asks who holds the keys, whether ten years of folders, versions and shares can be exported in a form another provider imports — and what leaving would cost.
Proton Drive
Tresorit
This judge's pick
Criterion by criterion
Sync, clients & file access
Proton Drive
Apps are documented for Windows, macOS, Android, iOS and the web plus a command-line tool, and the Windows client does real on-demand sync: cloud-only placeholders, per-file "Always keep on this device", offline edits that upload on reconnection, and uploads that resume after interruption, with "transfers without file size limits" stated. What I could not find is search of any kind, block-level sync, or access through WebDAV, SFTP or S3; the Linux option is a command-line tool, not a desktop client.
Tresorit
Clients for Windows, macOS, Linux, iOS and Android are documented, with camera upload, document scanning, sync across devices, files reachable from the local file manager, and stated file-size limits (10, 15 and 20 GB by plan; secure links up to 5 GB); an S3-compatible API exists but only for Business Pro and Enterprise. We found no public information on selective sync, block-level or delta sync, file previews, or search of any kind, so the access mechanics beyond the clients themselves are thin on the captured pages.
Sharing & external collaboration
Proton Drive
Links and email invitations carry password protection and expiry dates, viewer and editor roles, and one-click revocation that takes effect immediately, and recipients without a Proton account can view, upload and even edit documents, with download counts tracked and the sharer's IP hidden from recipients. Real-time co-editing is documented with the editor named (Proton Docs and Sheets), and editors' uploads count toward the owner's quota. I found no public information on download limits, watermarking, file locking, administrator-set link policies, or an access log per share.
Tresorit
This is close to data-room territory on paper: link expiry, passwords and open limits, disabled download and print, dynamic watermarks, access logs and link activity reports, auto-deletion when a link is revoked or expires, encrypted file requests from people without an account, end-to-end office editing built on Collabora, branded data rooms, and free Outlook, Teams and Gmail plug-ins. The zero-knowledge page states revocation immediately prevents previously authorized users from opening shared files, and sharing keeps the zero-knowledge model intact. We found no public information on file locking or full recipient identity verification beyond requiring an email to view.
Encryption, key custody & recovery
Proton Drive
Client-side encryption covers contents and metadata including file names, keys stay on the device, the scheme is named (OpenPGP, Curve25519), and sharing is stated to stay end-to-end encrypted with links generated locally. Independent Securitum audits with published reports, open-source apps, a public bug bounty capped at USD 100,000, ISO 27001 and SOC 2 Type II, SAML single sign-on, administrator-enforced two-factor, ten years of version recovery on paid plans and ransomware rollback put most of the top tier on the record. Two things hold me back from the last step: the certifications are stated without their scope, and no organisational key-recovery path is documented — the terms say plainly that the company has no ability to recover your data if you lose your password.
Tresorit
The core is strong and specific: AES-256 client-side zero-knowledge encryption with the scheme published (RSA-4096 with OAEP padding, a tree of symmetric keys, non-convergent cryptography, HMAC or AEAD integrity), an encryption whitepaper, passwords Tresorit itself cannot recover, admin key recovery only with user consent, two-factor authentication, version restore and deleted-file recovery, and ISO 27001:2022 stated. What a skeptic wants and does not find: no independent audit, penetration test or bug bounty is named, certification scope is not stated, folder and room names are by the terms' own statement not end-to-end encrypted and may be visible to Tresorit for support, and we found no public information on ransomware detection or restoring an account to a point in time.
Administration, audit & governance
Proton Drive
Three admin roles come with a documented permission matrix covering SAML and SCIM configuration, an activity monitor with read and export, and data-retention management, and administrators manage members, groups, per-user storage and password resets. What that activity monitor actually records is not specified, and I found no public information on legal hold, remote wipe or device management, IP restrictions, data classification or DLP, or SIEM streaming.
Tresorit
A central admin console with exportable audit logs of who accessed, shared or modified files, provisioning through Azure AD SCIM, Okta and Active Directory, SIEM streaming to Microsoft Sentinel, device and IP policies with remote blocking of lost devices, and granular policy templates at team and organization level are all documented. We found no public information on retention policies, legal hold, eDiscovery export, or data loss prevention and classification, and the audit log's retention period and completeness are not stated — so a regulated buyer can manage access here, not records.
Export, API & self-hosting
Proton Drive
A documented import path exists from Dropbox, documents export to.docx,.html,.txt,.md and.pdf, a command-line tool automates workflows, and the data processing agreement commits to deleting all company personal data when a service ends — while noting a copy of data must be requested before the account is deleted. I found no public information on a bulk export preserving folder structure and file versions, a REST API, SDKs or webhooks, open-protocol access, or a self-hosted edition.
Tresorit
What is documented: an S3-compatible API for Business Pro and Enterprise that replaces manual download-and-reupload with automated transfers, Microsoft 365, Outlook, Teams and Gmail integrations, a Bring Your Own Azure Storage arrangement keeping encrypted content in the customer's own storage account, and deletion of encrypted content within 90 days of removing a folder (60 days for technical reasons). We found no public information on a bulk export that preserves folders and versions, migration tools from any named provider, SDKs, webhooks, an app marketplace, or a self-hosted edition — so I cannot tell a buyer what leaving would actually cost in effort.
European sovereignty
Proton Drive
The contracting entity is Proton AG in Geneva under the supervision of the Swiss Proton Foundation, storage runs on the company's own hardware in Switzerland and Germany, and disclosure is limited to binding Swiss requests, with Swiss law said to prohibit sharing with foreign authorities. Subprocessors are listed with locations and transfer safeguards — though payment (Stripe, Chargebee, PayPal) and support (Zendesk, Hubspot) run through US providers under standard contractual clauses, with support also in Macedonia and Taiwan — and a data processing agreement is published that limits transfers to adequacy countries. The non-European payment and support chain, and ISO 27001 and SOC 2 stated without published scope, keep this short of fully sovereign.
Tresorit
The chain's head is genuinely European: Tresorit AG of Zurich, part of Swiss Post (covered by the Swiss adequacy decision), primary storage in the EEA or Switzerland, customer-selectable regions, a published subprocessor list and a published data processing addendum, and ISO 27001 stated. The fine print keeps it below the top: the terms acknowledge sub-processing in the United States and other countries, the residency option covers only content uploaded after the customer subscribes and selects a location while service data and metadata may remain outside it, and we found no public information naming the data centres or the location of each subprocessor.
Pricing transparency
Proton Drive
Drive Professional is listed at €7.99/month per user (regular €9.99) with 1 TB per user, consumer plans carry explicit annual totals ("Billed at €47.88 every 12 months" for Drive Plus, €119.88 for Unlimited), a free tier exists with a three-editor-link limit, and the terms spell out the 30-day refund with its limits, business reverse-charge VAT treatment and the billing cycles. I found no public price for extra storage or the enterprise tier, and no stated minimum number of users, so a buyer cannot fully compute cost at scale.
Tresorit
Per-user prices are public with storage, file-size limits and minimum users for the paid tiers — "€12 / user / month" from 3 users and "€20 / user / month" from 5 users, a 20% yearly discount, fees stated as exclusive of taxes, and auto-renewal, cancellation and no-refund terms in the terms of use. Enterprise is custom-priced from 50 users, and we found no public information on what extra storage costs or what the eSign add-on is priced at, so a full annual cost for a large team is not computable from the captured pages alone.
Sovereignty, side by side
Dimension
Proton Drive
Tresorit
Legal entity
Not determined
Not determined
Hosting location
Not determined
Not determined
Hosting options
Not determined
Not determined
Open source
Not determined
Not determined
Data processing agreement
Not determined
Not determined
Transfer impact assessment
Not determined
Not determined
Facts, side by side
Only facts both products carry under the same definition — anything else would not be a fair row.
As of 1 Nov 2026, the panel rates Tresorit higher: 3.5/5 against 3/5. Weighted by what each judge cares about, 0 of the 6 judges pick Proton Drive and 5 pick Tresorit, 1 calls it a tie. Which one fits depends on the criteria that matter to you; the table on this page shows both side by side, and each judge’s reading has its own page. Both were scored by the same AI bench under the same rubric, from public evidence only, as the methodology describes.
Is Proton Drive or Tresorit European?
Proton Drive is European (UK / wider Europe). Tresorit is European (UK / wider Europe). Provenance is read from each company’s own legal pages: who builds it and who owns it.
Do Proton Drive and Tresorit have a free plan?
As of 1 Nov 2026, both vendors’ own pages state a free plan. Each product page links the pricing page it was read from.