Filen is cloud storage run by a small company in Recklinghausen, Germany, on its own servers in German data centers. Filen says it encrypts every file on your device before upload, together with the file and folder names, so that it cannot read what you store. All of its apps are open source.

What Filen describes has not been checked by anyone outside the company. There has never been an independent security audit, and Filen now plans one only after a rebuild of its backend that has no date yet. Paid plans start at EUR 11.99 a year for 100 GiB, and 2 TiB costs EUR 89.99 a year.

Encryption & Key Custody

Filen’s key custody model puts the keys with you. Your password is turned into a master key on your device, and each file gets its own random key. Filen encrypts the file content in 1 MB pieces with AES-256-GCM, then encrypts the file name, size, type and the file’s key with your master key; folder names are encrypted the same way. Filen calls this zero-knowledge encryption; no independent audit has confirmed it. This metadata encryption also covers the account’s event log, Filen says.

The master key is derived from your password with PBKDF2, a key derivation function, at 200,000 iterations. Filen’s whitepaper says itself that PBKDF2 “is not the latest, best or state of the art”, chosen because browsers run it at native speed. A long, unique password matters more here than with a slower key-derivation method.

The web app works differently from the desktop and phone apps. It loads its encryption code from Filen’s servers every time you open it and keeps your keys in the browser’s local storage. If you use the web app, you are trusting Filen not to send altered code on any given visit. The desktop and phone apps run code installed on your device and change only when an update is installed.

Some things stay visible to Filen whatever the encryption: your email address, your IP address, how much storage you use, and payment references from PayPal, Stripe or Coinbase. Its documents do not say whether Filen can see when files are uploaded or opened. The privacy policy also says Filen keeps “a small amount of metadata about the file type”.

Sharing keeps the encryption in both of Filen’s modes. When you share with another Filen user, the file’s key is encrypted with that person’s public key. A public link carries its own key after the “#” in the address, a part that browsers do not send to the server; links can have a password and an expiry date. Public links work only on paid plans.

Account Recovery

If you forget your password, you lose every file in the account unless you exported your master keys beforehand (“Export master keys” in the account settings). That export is the only account recovery Filen offers: resetting the password without it creates new keys that cannot open anything you uploaded before. Store the exported key file somewhere other than the Filen account itself.

Two-factor login with an authenticator app is available. It comes with a recovery key that lets support restore your login if you lose the phone; it does not restore access to encrypted files.

Trust & Transparency

Filen publishes the code of its web, desktop, mobile and command-line apps on GitHub under the AGPL-3.0 open-source licence. The server code is not published, and Filen does not document reproducible builds, so you cannot confirm that the app in a store was built from the published code.

No independent audit of Filen’s encryption exists. Filen’s knowledge base says that an external company will test the service “in the future” with no date set, and the current roadmap moves the audit to after API v4, a backend rewrite that is itself only planned. The technical whitepaper dates from August 2021, and Filen says it is “slightly outdated”. Filen also ended its public bug bounty: it still reviews serious reports, but any reward is at its discretion.

Filen Cloud Dienste UG is registered in Recklinghausen and answers to German law. It publishes a PGP-signed warrant canary every week; the version of 14 October 2026 states that Filen has received no warrants, court orders, gag orders or requests for customer metadata. The company is run by Jan Lenczyk and says it has no outside investors. No data breach at Filen is known.

Features & Sync

The desktop app for Windows, macOS and Linux keeps folders in sync in five modes, including one-way backup, and can mount your storage as a network drive. The command-line tool can run a local WebDAV or S3 server for other software, and Filen is a built-in backend in rclone. The phone apps upload photos automatically. There is no file size limit, but there is no block-level sync either: a changed file is uploaded again in full.

File versioning keeps up to 100 versions of each file for as long as the file exists, and versions count toward your storage. Deleted files stay in the trash for up to 30 days.

Filen also includes encrypted notes and chats. Several people can edit a note together, and Filen says the notes stay end-to-end encrypted, so this is the only collaborative editing on offer: there is no editor for office documents, and Filen lists one only as planned. There are no family or business plans yet; each person needs a separate account.

Usability & Platforms

Filen has apps for Windows, macOS, Linux, Android and iOS, a web app and a command-line tool. Filen’s roadmap lists a rewrite of the sync engine and a redesigned desktop app as work in progress.

Signing up from a VPN, Tor or a proxy still creates an account, but without the free 10 GiB: Filen checks the IP address once at signup to stop people from creating free accounts in bulk. A free account cannot create public links and is deleted after 3 months without a login.

Price & Value

The free plan includes 10 GiB. Paid plans cost, per year: EUR 11.99 for 100 GiB (Starter), EUR 19.99 for 200 GiB (Pro I), EUR 39.99 for 500 GiB (Pro II), EUR 89.99 for 2 TiB (Pro III) and EUR 399.99 for 10 TiB (Pro X). Pro plans can also be paid monthly, from EUR 1.99 a month for 200 GiB. Plans stack on one account, and Filen says taxes and fees are included in the price. You can pay by card or PayPal; Filen says cryptocurrency cannot be used for subscriptions.

Refunds are possible within 14 days of the first purchase and not for renewals. If a plan ends while you store more than the free limit, you can still download your files, and data above the limit is deleted after 3 months.

Filen used to sell lifetime plans; Pro lifetime plans ended in 2025 and the cheaper Starter lifetime plan has been unavailable since January 2026. People who bought one keep it.

Pros and Cons

Files, file names, folder names and file metadata are encrypted on your device, according to Filen
Sharing with other users and public links keeps the encryption, with optional password and expiry on links
All apps are open source under AGPL-3.0
Keeps up to 100 versions of each file for as long as the file exists
Network drive, local WebDAV and S3 server, and a built-in rclone backend
2 TiB costs EUR 89.99 a year, and the free plan gives 10 GiB

No independent audit of the encryption, and the planned one has no date
The server code is not published
The password key uses PBKDF2, which Filen's own whitepaper calls not state of the art
The web app loads its encryption code from Filen on every visit
A forgotten password loses every file unless you exported your master keys
No office document editing and no family plan

Our Rating

Encryption & Key Custody8.0/10
The keys come from your password and stay on your devices, according to Filen, and file names, folder names and file metadata are encrypted along with the content. Sharing with other users and public links keep the encryption. The password key is derived with PBKDF2, which Filen's own whitepaper calls not state of the art, and the web app loads its encryption code from Filen on every visit.
Trust & Transparency5.0/10
All apps are open source under AGPL-3.0, the server code is not published, and there is no record of reproducible builds. No independent audit has been done: Filen promises one and now plans it after a backend rewrite that has no date. The whitepaper dates from 2021, and the public bug bounty has ended. A weekly signed warrant canary and German jurisdiction count in its favour, and no breach is known.
Features & Sync7.0/10
The desktop app syncs folders in five modes and mounts the storage as a network drive, the command-line tool serves WebDAV and S3 locally, and Filen works as a native rclone backend. It keeps up to 100 versions of each file with no time limit and has no file size limit. Shared editing covers only encrypted notes; there is no office editor. There is also no family plan and no block-level sync.
Usability & Platforms7.0/10
Apps exist for Windows, macOS, Linux, Android and iOS, plus a web app and a command-line tool. A forgotten password erases access to every file unless you exported your master keys beforehand. No free account can create public links, and one opened through a VPN gets no free storage.
Price & Value9.0/10
2 TiB costs EUR 89.99 a year and 200 GiB costs EUR 19.99 a year, with monthly billing available and plans that stack on one account. The free plan gives 10 GiB. Refunds are limited to 14 days after the first purchase, and lifetime plans are no longer sold.

Overall7.0/10

Encryption & Key Custody 30% · Trust & Transparency 25% · Features & Sync 20% · Usability & Platforms 15% · Price & Value 10%

See our rating methodology →