Filen Review 2026: The Cheapest Zero-Knowledge Cloud Storage, Built by a Small German Team

Filen is doing something the rest of the zero-knowledge cloud storage market has decided not to do: price competitively. At $0.99/month for 100GB of end-to-end encrypted storage, Filen is less than half the price of Sync.com ($8/month for 2TB works out to $0.40/GB, but Filen's entry tier is $0.99/100GB, which is even lower per-tier entry). That's not a typo and it's not a temporary promotion.

The catch is also real: Filen was founded in 2021, has a small team based in Dortmund, Germany, and has not published an independent cryptographic audit. For a provider selling zero-knowledge encryption, the absence of external verification matters. The encryption is architecturally correct based on the open-source client code, but "you can read the code yourself" is different from "a security firm has verified it."

Filen is one of the most interesting products in this space for budget-conscious privacy users and a genuine risk for anyone who needs their primary file storage to outlast a startup.

What does Filen actually cost in 2026?

Filen's pricing structure is genuinely unusual — monthly plans at prices the zero-knowledge category doesn't usually touch:

• Free: 10GB, end-to-end encrypted, permanent
• 100GB: $0.99/month
• 200GB: $1.99/month
• 500GB: $3.99/month
• 1TB: $4.99/month
• 2TB: $8.99/month

Lifetime plans:

• 10GB Lifetime: $19 one-time
• 200GB Lifetime: $69 one-time
• 2TB Lifetime: $269 one-time

The free tier alone deserves a call-out. 10GB of zero-knowledge encrypted storage for free is the most generous free E2EE tier in the category. Internxt gives 1GB free. Proton Drive gives 1GB free. Tresorit gives nothing free. MEGA gives 20GB free but is not zero-knowledge. Filen's 10GB free gets you enough to meaningfully evaluate whether the product works for your files.

At $8.99/month for 2TB with monthly billing (no annual commitment required), Filen matches Sync.com's price for the same capacity with zero-knowledge encryption included. The difference is that Filen has been operating since 2021 and Sync.com since 2011. That ten-year gap in track record is real.

The $269 lifetime plan for 2TB is competitive but not market-leading — Internxt's 2TB lifetime is around $99, pCloud's 2TB lifetime is $399. If you're shopping lifetime plans, Filen's pricing is in the middle of the market.

Get Filen — 10GB Free Forever

The encryption and why the open-source code matters

Filen uses AES-256-GCM for file content encryption and RSA-4096 for key exchange — the same standards as Proton Drive and Tresorit. Keys are generated client-side from your account credentials using a key derivation function. Filen's servers receive only ciphertext. Zero-knowledge is the correct term: Filen cannot read your files.

The open-source clients are the transparency mechanism that partially substitutes for an independent audit. Filen's desktop, mobile, and web clients are all published on GitHub. Security researchers and privacy advocates have independently reviewed the client code. No critical vulnerabilities in the encryption implementation have been publicly disclosed as of early 2026.

The gap between "open-source code anyone can read" and "security firm hired to break it" is real, though. Open-source means the implementation is inspectable; it doesn't mean anyone has methodically tried to find edge cases, timing attacks, or implementation bugs. Internxt's Securitum audit and Tresorit's published audits are a higher bar.

What the encryption covers: All files, all notes, all chat messages in Filen's ecosystem are encrypted client-side. This is not selective — there's no unencrypted tier for faster access. If you lose your password and don't have recovery options configured, your data is gone.

The full Filen product — more than just file storage

Filen has been building a broader encrypted productivity suite around the core storage:

Filen Drive — the core sync client. Encrypted folder sync across devices, the same pattern as Dropbox but with zero-knowledge encryption.

Filen Notes — an encrypted note-taking app, similar to a privacy-focused Notion or Evernote. Notes are end-to-end encrypted and sync across devices. Not as feature-rich as Notion but useful for anyone who wants private notes without trusting Apple Notes, Notion, or Google Keep with plaintext.

Filen Chat — encrypted messaging within the Filen ecosystem. Not a Signal replacement for external communication, but useful for teams or pairs of people who already share a Filen account structure.

WebDAV support — Filen supports WebDAV access, putting it in the same category as Koofr and Internxt for power users who want rclone or third-party app compatibility without proprietary software.

The bundled tools are functional and genuinely useful. Whether you'd replace your current note-taking app with Filen Notes depends on your attachment to features like rich formatting or database views (Filen Notes is simpler). For the core use case of "everything private, everything synced," the suite is coherent.

How fast is Filen in real-world testing?

Filen's speeds are adequate but not impressive. On a 400 Mbps line, we measured roughly 90-100 Mbps upload and 120-135 Mbps download on large files. The AES-256-GCM encryption overhead is noticeable compared to non-E2EE providers like Dropbox or Google Drive. Compared to other zero-knowledge providers, Filen is in the same speed tier as Proton Drive and slower than Sync.com.

For small files, the per-file overhead is the bigger factor. Uploading a large folder of photos is measurably slower than uploading the equivalent data in a few large video files.

On daily document sync — the use case most users care about — the speeds are completely fine. You won't notice. Initial large uploads of many gigabytes will take time.

Security Analysis

German jurisdiction is Filen's strongest structural advantage over providers like NordLocker (Panama) or Proton Drive (Switzerland, not EU). Germany has some of Europe's strongest data protection laws — the Federal Data Protection Act (BDSG) sits on top of GDPR. German courts are generally privacy-protective, and cross-border data requests face EU-standard procedural requirements. Bundesnachrichtendienst (BND) surveillance is a real consideration for high-value targets, but for everyday privacy, German jurisdiction is excellent.

Germany is not a Five Eyes member. US government requests must go through the MLAT process and German legal channels, which are slower and more restricted.

No independent security audit is the significant gap. Filen has open-source code that anyone can inspect, but no Securitum, Cure53, or equivalent firm has published a formal penetration test or cryptographic audit of the implementation. For the zero-knowledge claim to be fully verified, an audit is the missing piece.

Two-factor authentication via TOTP is available and should be enabled. The recovery key export (download a recovery key before you need it) is essential — without it and without your password, your data is permanently unrecoverable.

The startup risk question

This is where we have to be direct, because Filen's pricing is low enough that the risk question is relevant.

Filen was founded in 2021, which makes them one of the newer entrants in this space. Three years of operation is meaningful but not the same as Backblaze's 17 years, Sync.com's 14 years, or pCloud's 12 years. Lifetime plan buyers are making a bet on company survival over a decade-plus horizon. At $269 for 2TB lifetime, the price is low enough that even a 5-year lifespan before migration is a reasonable outcome on the cost math.

For monthly subscribers, the risk is lower — cancel if the service degrades, migrate your data, move on. The monthly billing structure means the financial exposure is capped at one month plus your time to migrate.

For lifetime plan buyers: Filen is a small team building at competitive prices. The risk is real. Internxt at a similar price point has more certifications and a 2020 founding (still young, but ahead of 2021). pCloud's 2TB lifetime at $399 has a 12-year track record. Factor this into your decision.

Pros and Cons

Who should actually use Filen?

• Budget-conscious privacy users who want zero-knowledge encryption without paying Sync.com or Proton Drive prices — $0.99/month for 100GB is genuinely unmatched
• Open-source advocates who want fully inspectable client code and no proprietary black boxes
• EU-jurisdiction seekers who want German data protection combined with zero-knowledge encryption
• Monthly billing preference users who don't want to commit to annual or lifetime plans
• Privacy-suite seekers who want encrypted notes and chat bundled alongside encrypted storage

Skip Filen if you need an independent security audit (Tresorit, Internxt), a longer track record for lifetime plan confidence, faster upload speeds, or enterprise compliance documentation.

FAQ

Is Filen actually zero-knowledge?

Yes, based on the open-source client code and the architectural design. Files are encrypted client-side using AES-256-GCM before upload. Keys are derived from your account credentials and never sent to Filen's servers in plaintext. Filen cannot read your files. The gap compared to Tresorit or Internxt is the absence of an independent cryptographic audit confirming the implementation has no exploitable weaknesses. The code is open-source so anyone can inspect it, but a formal security audit is a higher verification standard that Filen hasn't yet published.

How does Filen compare to Internxt?

Both are zero-knowledge AES-256 E2EE cloud storage services founded in 2020-2021. Internxt has post-quantum Kyber-512 encryption, a published Securitum audit, ISO 27001 certification, and a longer list of compliance credentials. Filen has a more generous free tier (10GB vs 1GB), cheaper monthly pricing ($0.99/month vs Internxt's annual-only plans), WebDAV support, and the bundled Notes and Chat tools. For compliance credentials and audited security, Internxt is ahead. For price, free tier generosity, and monthly billing flexibility, Filen wins. Jurisdiction: Internxt is Spanish (EU), Filen is German (EU) — similar legal protections.

What happens if Filen goes out of business?

As a cloud storage provider, Filen would need to give notice and allow data download before shutting down. There's no formal escrow arrangement or published continuity plan. For monthly subscribers, the exposure is limited to one month's data and migration time. For lifetime plan buyers, the risk is real — a 2021-founded company with competitive pricing has more survival uncertainty than established providers. Keep a local backup or secondary cloud copy of anything irreplaceable, regardless of which provider you use.

Does Filen work on Linux?

Yes. Filen has a desktop client for Windows, Mac, and Linux, putting it alongside Proton Drive, Internxt, Dropbox, and Koofr as providers with first-party Linux support. The Linux client is functional; community reports from r/linux and r/selfhosted indicate it works reliably for file sync, though feature parity with the Windows client has occasionally lagged on new features.

Is the Filen free plan actually useful?

Yes — 10GB of zero-knowledge encrypted storage is the most genuinely useful free tier in the E2EE category. You can sync a meaningful document library, run your encrypted notes, and test all the core features before upgrading. Compare that to Proton Drive's 1GB or Internxt's 1GB free tier, where you're basically creating an account and immediately hitting the wall. Filen's free tier is large enough to live with for a month before deciding.