"End-to-end encrypted" storage means the provider never holds a
usable decryption key—only you (and anyone you deliberately share a
key with) can open your files. This is different from "encrypted at
rest," which just means the provider's disks are encrypted while the
provider itself still holds the keys.
Below are two families: native zero-knowledge providers (Proton
Drive, Tresorit, Sync.com, MEGA) that build encryption into their
own sync client, and self-hosted platforms (Nextcloud, Seafile)
where you run the server and decide the jurisdiction yourself.
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Proton Drive applies the same zero-access encryption model as
Proton Mail to file storage: files are encrypted client-side and
Proton cannot decrypt them. It's the newest of the major
zero-knowledge providers, so its sync client and large-file
performance are still catching up to Tresorit and Sync.com, but
it's the simplest choice if you already use Proton Mail or VPN
and want one encrypted account for everything.
Pros
Zero-access encryption, Swiss jurisdiction
Bundles with Proton Mail, VPN, and Pass under one account
Free tier included
Regularly audited
Cons
Sync client is younger and slower on large first-time
uploads
Fewer third-party integrations than legacy cloud providers
Higher tiers push you toward the full Proton bundle
Ideal for: Existing Proton users who want
encrypted storage without adding another vendor.
Pricing: Free tier around 2–5GB; Drive Plus
around $5/mo for 200GB; higher storage bundled into Proton
Unlimited. Platforms: Web, Windows, macOS,
Linux, Android, iOS.
Why it's here: The default pick for anyone
already inside the Proton ecosystem.
Tresorit leans hardest into compliance: ISO 27001 certification,
HIPAA support, and regular third-party audits make it the go-to
for regulated professions like law and medicine. Files are
encrypted locally before upload with granular sharing controls,
but that rigor comes at the highest price per gigabyte of the
group.
Pros
ISO 27001, HIPAA-capable, independently audited
Granular sharing and access controls built for teams
Swiss and EU infrastructure options
Cons
Most expensive per gigabyte on this list
Sync UI is less modern than newer competitors
Overkill for casual personal use
Ideal for: Professionals in regulated fields
(legal, medical, finance) who need documented compliance.
Pricing: No permanent free tier; individual and
business plans priced well above consumer competitors.
Platforms: Web, Windows, macOS, Linux, Android,
iOS.
Why it's here: The pick when a compliance
officer needs a named certification, not just 'encrypted.'
Sync.com, based in Canada, undercuts both Proton Drive and
Tresorit on price per gigabyte while still offering full
zero-knowledge encryption and a notable 365-day file version
history as a ransomware safety net. It's a solid middle ground
for readers who want encrypted storage without paying an
enterprise premium or a Swiss/German privacy narrative.
Pros
Best price-to-storage ratio among zero-knowledge providers
365-day version history included
True zero-knowledge encryption on all plans
Cons
Canadian jurisdiction is fine, but not Swiss/German-tier
legally
Fewer ecosystem integrations than Proton
Interface is functional, not flashy
Ideal for: Readers who want the cheapest
genuinely zero-knowledge storage without compromising on
encryption.
Pricing: No permanent free tier beyond a small
trial; paid plans undercut Proton Drive and Tresorit on storage
per dollar. Platforms: Web, Windows, macOS,
Android, iOS.
Why it's here: Included as the value pick—same
zero-knowledge guarantee, lower cost.
MEGA offers 20GB free with client-side encryption on every plan,
free and paid—the most generous free allowance of any
zero-knowledge provider. Users hold their own encryption keys,
and MEGA also bundles end-to-end encrypted chat and calls. It's
less suited to real-time document collaboration than Google
Drive or Nextcloud, so treat it as storage and sharing rather
than a workspace.
Pros
20GB free storage, client-side encrypted by default
Encrypted chat and calls included
No paywalled encryption tier—free users get the same
protection as paid
Cons
Not built for real-time collaborative editing
Past corporate history draws scrutiny from some privacy
reviewers
Desktop client can be resource-heavy
Ideal for: Readers who want the largest free
encrypted storage allowance with no strings attached.
Pricing: Free tier at 20GB; paid plans scale
storage and bandwidth from there.
Platforms: Web, Windows, macOS, Linux, Android,
iOS.
Why it's here: The free-tier pick—hard to beat
on storage-per-dollar at zero cost.
Nextcloud is open-source, self-hosted cloud storage with
optional end-to-end encryption, giving you full control over
where your data physically sits and who can subpoena it. It
trades convenience for ownership—you run the server (your own
hardware, a VPS, or a managed Nextcloud host) and you're
responsible for backups, updates, and uptime.
Pros
Full data ownership—your server, your jurisdiction
Open source with a large plugin ecosystem
No recurring vendor fee beyond hosting costs
Cons
You are the sysadmin—backups and updates are on you
End-to-end encryption is opt-in, not default
Initial setup has a real learning curve
Ideal for: Technically comfortable readers who
want total control and don't mind running a server.
Pricing: Free, open source; cost is whatever
hosting you choose (self-owned hardware, VPS, or a managed
Nextcloud provider). Platforms: Self-hosted
server (Linux); clients for Windows, macOS, Linux, Android, iOS.
Why it's here: The self-hosted anchor of this
list—maximum control for those willing to maintain it.
Seafile is a leaner open-source self-hosted alternative to
Nextcloud, organizing files into libraries that sync and encrypt
independently with user-defined passwords. It's generally faster
and lighter on server resources than Nextcloud, at the cost of a
smaller plugin ecosystem and fewer built-in office-suite
features.
Pros
Lighter and often faster than Nextcloud on modest hardware
Per-library password-based encryption
Open source with version control and sharing
Cons
Smaller ecosystem and community than Nextcloud
Less polished collaboration tooling
Still requires you to run and maintain a server
Ideal for: Self-hosters who want
Nextcloud-style ownership with a lighter footprint.
Pricing: Free, open source community edition;
paid professional edition adds enterprise features.
Platforms: Self-hosted server (Linux, Docker);
clients for Windows, macOS, Linux, Android, iOS.
Why it's here: A practical alternative for
readers who found Nextcloud too heavy.
Zero-knowledge means no password recovery. If you
lose your master password or recovery key on a true zero-knowledge
service, the provider cannot help you get your files back—that's
the same math that keeps them out.
Self-hosting shifts the risk, it doesn't remove it.
Running Nextcloud or Seafile yourself means you're now the one
responsible for patching, backups, and physical security.
Sharing links can undo encryption's benefit. A
shared link with a weak or no password is a hole in an otherwise
encrypted vault—treat sharing settings as seriously as the
encryption itself.
What's the difference between 'encrypted at rest' and
'zero-knowledge'?
Encrypted at rest means the provider's disks are encrypted but
the provider still holds the keys and can technically read
your files. Zero-knowledge means the provider never has a
usable key at all—only you can decrypt.
Should I self-host or use a managed provider?
Self-hosting (Nextcloud, Seafile) gives you full
jurisdictional control but makes you responsible for uptime
and security patching. A managed zero-knowledge provider
trades some of that control for convenience and professional
infrastructure.
Can I add encryption to Google Drive or Dropbox instead of
switching?
Yes—tools like Cryptomator (see our file encryption guide)
encrypt files locally before they sync to any existing cloud
provider, letting you keep your current storage while adding a
zero-knowledge layer on top.
