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OneTask

Free task app that syncs Google, Outlook and CalDAV task lists

FreeTo-Do ListsChecked Oct 9, 2026
Visit onetask.eu

What is OneTask?

OneTask is a task and to-do list app for Android, iPhone, iPad, Mac and Windows from the Dutch developer Code Spark. It works as a client for task lists held elsewhere: Google Tasks, Outlook, Office 365, iCloud Reminders and CalDAV servers such as Nextcloud and Synology. Tasks sync directly between the device and the provider, and the store listings, which title it One Task or One Tasks, show it as a free download.

OneTask is free to use. See every plan

Good for

  • People with tasks split across Google and Microsoft accounts
  • Users of Nextcloud, Synology or another CalDAV server
  • Anyone who also uses Code Spark's OneCalendar app

Worth knowing

  • There is no web version; the site lists apps for Android 6 and higher, iPhone, iPad, Mac and Windows 10 and 11 only.
  • It has no task service of its own: tasks live in a connected Google, Microsoft, iCloud or CalDAV account.
  • Google Play and the Microsoft Store label the app as having in-app purchases, but no listing or vendor page shows a price for one.
  • The app is titled One Task on Google Play and the Microsoft Store and One Tasks on the App Store, not OneTask.

Key features

Several task providers in one app
Accounts from Google Tasks, Outlook, Office 365 and iCloud Reminders can be added side by side, so task lists from each appear in one place.
CalDAV task lists
Any third-party CalDAV server can be added with a username, password and server address. Nextcloud, Synology and Mailbox.org have dedicated account types.
Subtasks, due dates and reminders
Tasks can carry subtasks, due dates and reminders, and widgets show tasks outside the app.
Offline use
The site and the Microsoft Store listing both list working offline, without an internet connection, as a feature.
Views, search and theming
The app offers multiple views of task lists, task search and personalized color themes.
Direct sync with no vendor server
The privacy policy says task data is not stored on Code Spark's servers. Google and Microsoft accounts sign in with OAuth 2.0, and the token is stored encrypted on the device.

OneTask pricing

Starts at
Free
Free plan
The app is a free download on the App Store, Google Play and the Microsoft Store. The US App Store listing shows no in-app purchases.
Free trial
None listed
Free$0The full app on iPhone, iPad, Mac, Android and Windows, connected to the user's own task accounts.

Read from apps.apple.com on Oct 9, 2026. Prices change, so confirm with OneTask before you buy.

Pricing in detail

Works with

OneTask alternatives

All OneTask alternatives comparedAll to-do list apps

Common questions

Is OneTask free?

Yes. OneTask is free to use. The app is a free download on the App Store, Google Play and the Microsoft Store. The US App Store listing shows no in-app purchases.

How much does OneTask cost?

OneTask lists one plan. Free: $0. Prices were read from apps.apple.com on Oct 9, 2026.

What platforms does OneTask work on?

OneTask is available on iOS, macOS, Windows and Android.

Does OneTask have a Linux app?

No Linux app was listed when its pages were read on Oct 9, 2026. OneTask is listed for iOS, macOS, Windows and Android.

Is OneTask open source?

OneTask is not described as open source on its own site, as read on Oct 9, 2026.

Does OneTask work offline?

Yes, according to its own site. What works without a connection differs by plan and platform, so check the vendor's page for the detail.

What does OneTask integrate with?

OneTask's listing names Google Tasks, Outlook, Office 365, iCloud Reminders, OneCalendar, Nextcloud, Synology and Mailbox.org. A listing names up to eight integrations, so it may connect to more.

Who makes OneTask?

OneTask is made by Code Spark. It dates from 2016.

What are the alternatives to OneTask?

The closest alternatives to OneTask in our directory are Tasks.org, Google Tasks, Microsoft To Do, 2Do and TasksBoard. Each one has a side-by-side comparison with OneTask.

Sources for this page

The prices, plans, platforms and features above were read from these pages on Oct 9, 2026.