Transfer, Sync & Back Up Proton Drive to Any Cloud

What is Proton Drive?

Proton Drive is the end-to-end encrypted cloud storage from the Swiss team behind Proton Mail. Every file is encrypted on your device before upload with a key only you hold — Proton themselves cannot read your files, and neither can Proton's hosting provider or any government subpoena. Built on open-source cryptography (OpenPGP + AES-256-GCM), audited by independent security firms, and hosted in Switzerland under some of the strongest privacy laws in the world. Free plans start at 5 GB; paid Proton Unlimited and Proton Business plans go up to 500 GB, 3 TB, 6 TB and higher.

Moving data into or out of Proton Drive is unusual because of the encryption model. Proton's own web and desktop clients handle the crypto automatically, but most third-party tools cannot — which is why cloud-to-cloud migrations involving Proton Drive historically meant download-everything-locally-then-re-upload. CloudsLinker integrates directly with Proton's API using your credentials to decrypt during transfer and re-encrypt on the other side, letting you move files between Proton Drive and 140+ other clouds server-to-server.

Key features of Proton Drive

Swiss end-to-end encryption

All files are encrypted client-side with keys only you hold. Proton cannot access your content; neither can any third party, including CloudsLinker — we use your credentials solely to derive the session keys during transfer.

5 GB free, up to 3 TB+ paid

Free plan: 5 GB (after completing setup actions). Proton Unlimited: 500 GB. Proton Business: 1 TB/user up to 3 TB. Duo / Family plans available.

Open source & audited

Proton Drive's clients are open-source and audited by Securitum. The crypto is standard OpenPGP + AES-GCM — no proprietary obscurity.

Version history

Paid plans keep file version history for 10 years on Proton Business / Unlimited. CloudsLinker copies the current version by default.

Swiss jurisdiction

Proton operates under Swiss law, which requires a local Swiss court order for any data request — and since Proton holds no plaintext, such requests return only encrypted blobs.

Zero-knowledge by design

Even Proton's own staff cannot access customer files. Password resets on a forgotten password lose access to the data, because the encryption key is derived from the password.

Why connect Proton Drive to CloudsLinker

CloudsLinker authenticates to Proton Drive with your Proton email + password (and a 2FA code if you have 2FA enabled). The session derives the same encryption keys Proton's native clients use, so CloudsLinker can read and write files with full end-to-end protection. Files are decrypted only in-memory on the transfer worker, never written to disk in plaintext, and are re-encrypted for the destination cloud if it supports encryption. This lets you migrate out of Proton, move into Proton, or use Proton as an encrypted off-site backup for any of your other clouds.

What you can do with Proton Drive on CloudsLinker

End-to-end encrypted transfers

CloudsLinker decrypts only in memory during the transfer worker. Files are never written to disk in plaintext, and re-encrypted for the destination where supported.

Runs without your device

Proton transfers execute on CloudsLinker's servers, not your computer. Close the laptop — the job keeps going.

Scheduled encrypted backup

Use Proton Drive as an encrypted vault for backup of Google Drive, OneDrive, Dropbox or S3 — schedule nightly incremental jobs.

Filter by folder, type, size

Copy only <code>/Photos</code>, skip files > 2 GB, or sync only <code>.pdf</code> and <code>.zip</code> files.

Common Proton Drive transfer scenarios

Encrypted off-site backup: Google Drive / Dropbox → Proton Drive

If you've got 500 GB of personal files in Google Drive but want a privacy-respecting backup, schedule a nightly CloudsLinker incremental from Google Drive to Proton Drive. Each backup lands encrypted in Switzerland, only you hold the key, and you keep using Google Drive as your everyday working storage.

Leave Google / Microsoft for a privacy-first stack

Migrating the family from Google Photos + Drive to Proton Drive + Proton Photos? CloudsLinker performs the full copy server-to-server, preserving folder hierarchy and modification dates. Once the migration verifies, you can cancel Google One and move to Proton Unlimited without ever running a local sync.

Replicate Proton Drive to a second provider (belt-and-suspenders privacy)

Even privacy-focused users want redundancy. Run a scheduled CloudsLinker sync from Proton Drive to an encrypted S3 bucket with your own KMS key — you'll have two independent encrypted copies in different jurisdictions.

Migrate from Cryptomator / Boxcryptor into Proton Drive

Users of legacy client-side encryption tools often consolidate on Proton Drive. CloudsLinker decrypts the source (given the Cryptomator vault key) and re-uploads to Proton with Proton's native encryption, so the files are readable from Proton's mobile / web apps.

Move sensitive business files out of US-based clouds

For compliance-sensitive teams (legal, healthcare, journalism), storing documents under the US CLOUD Act is a risk. Schedule a CloudsLinker migration from Dropbox / Google Drive / OneDrive to Proton Drive — Swiss jurisdiction + zero-knowledge encryption.

How to connect Proton Drive to CloudsLinker

Proton Drive authenticates with account credentials (email + password) plus a 2FA code if you have 2FA enabled.

Security note

Proton Drive is end-to-end encrypted — your password is also the root of your encryption key. CloudsLinker needs the password to derive the session keys and read / write your files. Your password is encrypted at rest on CloudsLinker’s side with AES-256, and only decrypted in-memory inside the transfer worker while a job is running.

For the strictest posture, create a Proton App Password (if available on your plan) or a dedicated Proton account scoped to just the files you’re migrating.

Connection steps

In CloudsLinker, click Add Cloud → choose Proton Drive.
Enter your Proton email address ([email protected]) and Proton password.
If you have 2FA enabled on your Proton account, you’ll be prompted for the 6-digit TOTP code from your authenticator app. Enter it and continue.
Click Confirm. CloudsLinker derives the session encryption keys, validates the connection by listing your Proton Drive root, and shows the cloud as ready.

To revoke access later: https://account.proton.me → Security → Sessions → sign out the CloudsLinker session. Or change your Proton password — this invalidates all existing sessions.

Proton Drive upload & download limits you should know

Proton Drive is unusually permissive on per-file and bandwidth limits, because the design philosophy is “you bring the storage plan, we provide the encryption.” The practical limits are:

Maximum single file size: no hard limit. File size is bounded only by your plan’s available storage quota. Very large files (multi-GB) are split into encrypted chunks automatically by the protocol.
Storage: 5 GB free (after completing setup actions — starts at 2 GB before), 500 GB on Proton Unlimited, 1 TB per user on Proton Business (up to 3 TB pooled for enterprise), 6 TB on Duo / Family tiers.
Bandwidth: no imposed cap on your own uploads / downloads. Throughput is limited by your internet connection and Proton’s API — typical sustained speeds are 20–80 MB/s depending on region and file size (encryption overhead is the main bottleneck, not the network).
Sharing bandwidth: when sharing files via link, Proton does not publish a hard transfer cap, but rate-limits abusive patterns.
Version history: 10 years on Proton Unlimited / Business / Family — longer than almost any competing cloud. CloudsLinker copies the current version by default.
Trash retention: 30 days before permanent deletion.
End-to-end encryption: all files are encrypted client-side before leaving the CloudsLinker transfer worker. Even Proton staff cannot decrypt them.

Sources: Proton: Drive support documentation, Proton: Send large files with Proton Drive, Cyberly: Proton Drive file size limit.

Proton Drive + CloudsLinker — Frequently Asked Questions

Is CloudsLinker able to read my Proton Drive files?

Only in-memory during an active transfer, and only because you provided the password needed to derive the session keys. Files are decrypted on the transfer worker, streamed to the destination, and cleared from memory — never written to disk in plaintext on CloudsLinker's infrastructure.

Do I have to disable 2FA to connect Proton Drive?

No. If 2FA is enabled on your Proton account, CloudsLinker will prompt for the 6-digit TOTP code during connection. The code is one-shot and never stored.

What's the largest file I can transfer with Proton Drive?

Proton Drive has no hard per-file size limit — the only cap is your plan's available storage. In practice, files above a few hundred GB may hit network timeouts during the encryption / upload cycle; CloudsLinker handles these by chunked upload with resumable checkpoints.

Does Proton Drive charge for bandwidth or set download quotas?

No. Proton does not impose bandwidth limits on your own files — you can upload and download as much as fits in your storage quota. The practical limit is your internet connection speed and Proton's API throughput (CloudsLinker uses the same API the Proton apps use).

Are transfers between Proton Drive and other clouds still private?

On CloudsLinker's side, transfers run over TLS and files are handled only in memory during the worker's lifetime. However, once the data is written to the destination cloud, it inherits that cloud's privacy posture. If you want to maintain end-to-end encryption on the destination, back up to Proton (not from), or use an encryption-aware destination.

What if I have Proton Business / Duo / Family?

CloudsLinker works with all Proton plans. On Business, each user authorizes their own Proton account; there's no tenant-level OAuth at this time. For large migrations, we recommend running per-user jobs in parallel.

Does CloudsLinker preserve Proton Drive's encryption when migrating <em>into</em> it?

Yes. When the destination is Proton Drive, CloudsLinker uses Proton's native encryption pipeline — files are encrypted client-side on the transfer worker before being uploaded, using the keys derived from your Proton session. The destination Proton Drive sees the same encrypted blobs it would see from any other Proton client.

Can I back up encrypted Proton Drive files to an unencrypted cloud?

Yes, but the backed-up files will be decrypted on the destination (since the destination cloud has no way to read Proton's encryption). For a privacy-preserving backup, we recommend keeping Proton as the destination, not source.

How does revocation work?

Change your Proton password at account.proton.me — this invalidates any existing CloudsLinker session and you'll need to reconnect. You can also sign out other sessions from Proton's Security settings.

Is this officially endorsed by Proton?

No. CloudsLinker is a third-party tool that uses Proton's public API under your credentials. Your account remains fully under your control.

Proton Drive transfer guides

Step-by-step walkthroughs for moving data to and from Proton Drive.

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Conclusion

Proton Drive is the gold standard for privacy-respecting cloud storage — but its encryption model also makes it one of the hardest clouds to integrate with third-party transfer tools. CloudsLinker is purpose-built to preserve Proton's end-to-end encryption during cloud-to-cloud transfers, letting you use Proton Drive as either a source or a destination without ever downloading plaintext to your local machine.

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