End-to-end encryption

Nydhei is private by design. Your content is end-to-end encrypted, which means it’s locked on your device before it ever syncs — and only your devices hold the keys to read it.

What this means

The things you write — your notes, your tasks, the words you choose — are readable only on your own devices. Nobody else can read them, because nobody else has the keys.

Only your devices can read these after sync.

What’s encrypted

Nydhei is open about exactly what is protected.

Encrypted, readable only on your devices:

• Task titles, descriptions, and subtasks
• Note titles and content
• Comment text
• Category and tag names
• List names, structure, and the items inside them

Not encrypted (the plumbing that makes sync work, never your words):

• Dates and timestamps, including due dates and scheduling
• Task status, priority, and recurrence settings
• Which category, tag, or list an item belongs to
• Sync metadata and IDs

Good to know

• Because only your devices can read your content, keep your recovery phrase safe — it’s how you regain access if you lose your devices.
• Adding a new device uses a secure key transfer. See Linking a device.