How Diarium Keeps Journal Entries Private and Where Your Data Is Stored

Diarium keeps entries private by default: you can start journaling without creating an account, entries can stay on your device, and optional protection is available through a password, PIN, or biometrics. If you want the same journal on multiple devices, sync is optional and runs through your own cloud storage — OneDrive, Google Drive, Dropbox, iCloud, or WebDAV — rather than a Diarium-operated account. This suits people who want a local-first diary and are willing to manage their own cloud storage if they choose to sync.

Privacy by default: no account required

Diarium does not require an account or sign-up. According to the app's own description, you can "start journaling in under a minute" with no login. That means there is no Diarium profile holding your entries by default — the starting state is a journal that lives on your device.

This matters if your main concern is avoiding yet another online account tied to personal writing. The trade-off is that account-free also means there is no vendor-side recovery service described: protecting access and backing up your data is something you handle.

Where your data lives

Two conditions apply to sync, both stated in the app's feature overview:

• Sync requires the Pro version. It is not part of the base setup.
• Sync uses your own cloud storage, not a Diarium-hosted server. You stay in control of the storage account and its access settings.

Diarium Pro is described as a one-time purchase per platform rather than a subscription. The site does not list prices, so check the store listing for your platform before buying.

Locking the app itself

Entries can be protected with a password, PIN, or biometrics. In practice this is the layer that stops someone holding your unlocked phone or laptop from opening the journal. It is separate from cloud storage security: if you enable sync, the protection of the synced copy depends on your cloud provider's account security, so use a strong password and two-factor authentication there as well.

What else the journal can hold

Privacy decisions get harder as a journal accumulates more personal material. Diarium supports:

• Unlimited attachments — photos, videos, audio recordings, PDFs, and other files
• Rich text formatting, tags, locations, and dictation
• Multiple entries per day, or one entry split with timestamps
• Map, gallery, calendar, and timeline views, plus "On this day" reminders
• Optional integrations that surface photos, calendar appointments, social media posts, fitness data, and weather as context for an entry

If you connect those integrations, be aware that the context shown in your journal can include data from other services. The app states entries stay private and that there are no ads, but the site does not detail exactly what each integration transmits — review the integration settings if that matters to you.

Deciding whether this fits your privacy needs

Choose Diarium if you want a cross-platform diary (Windows, Android, iPhone, iPad, Mac) that works without an account, keeps entries on-device unless you opt in, and lets you point sync at storage you already control.

Look elsewhere if you need a provider-managed encrypted backup with account recovery, or if you are unwilling to pay for Pro to sync across devices. The site does not describe end-to-end encryption of synced files, so if that is a hard requirement, confirm it before relying on cloud sync for sensitive entries.