Cryptomator
Cryptomator is a free and open-source client-side encryption tool for cloud storage that encrypts your files locally before they sync to services like Dropbox, Google Drive, OneDrive, and Nextcloud. It creates encrypted vaults that appear as virtual drives on your computer, allowing you to work with your files normally while everything is transparently encrypted and decrypted on the fly. With support for all major cloud providers and a mobile companion app, Cryptomator puts you in control of your cloud data without requiring any changes to your workflow.
Key Features
- Client-side encryption — Files are encrypted on your device before they are uploaded to the cloud, meaning no cloud provider or third party can read your data — even if they are compelled to hand it over
- Transparent vaults — Encrypted vaults mount as virtual drives on your computer; you drag files in and out like a USB stick, with encryption and decryption happening automatically in the background
- Standard-compliant cryptography — Uses AES-256 with GCM mode for file encryption and 256-bit keys derived via scrypt, following the latest cryptographic standards
- Directory obfuscation — Encrypts file and folder names as well as file contents, so cloud providers cannot see what types of files you store
- Cross-platform support — Desktop apps for Windows, macOS, and Linux, plus mobile apps for iOS and Android for accessing vaults on the go
- Open source and audited — Fully open source (MIT Licence) with regular third-party security audits; the code is transparent and independently verified
- No account required — Cryptomator has no user accounts, no telemetry, and no data collection; it is entirely self-contained software
- Local file recovery — Stores a local backup of your vault configuration, so you can recover access even if the cloud copy becomes corrupted
Why Use Cryptomator?
Cloud storage services are convenient, but they also mean your files sit on someone else’s server — accessible to the provider, potential hackers, and government surveillance. Cryptomator solves this by making the encryption happen on your own device with keys only you control. Even if your cloud account is compromised or the provider is legally compelled to hand over your data, all anyone sees is encrypted gibberish. It works with any cloud storage service that syncs a local folder, and the virtual drive interface means you do not need to change how you work.
Use Cases
- Protecting sensitive documents in the cloud — Encrypt client files, legal documents, tax records, and medical information before syncing to any cloud provider
- Privacy for cloud collaboration — Store shared project files in cloud drives without exposing them to the cloud provider or third parties
- Backup encryption — Encrypt local backups before sending them to cloud storage or off-site backup services
- Travel with encrypted data — Keep sensitive files in a Cryptomator vault on a cloud-synced folder, accessible from any device anywhere
Platform
Linux · macOS · Windows · Android · iOS
Licence
MIT Licence (dual-licensed: MIT for source, GPLv3 for some components)