The OneTask Insider’s Guide
Everything we know about OneTask in one document: what it costs, its grades, getting a refund, getting help and what else to look at. Read it here, or keep a copy.
OneTask
The Insider’s Guide
Free task app that syncs Google, Outlook and CalDAV task lists
Every plan, grade, refund rule and rival among to-do list apps, read from OneTask’s own pages.
Made by Code Spark · checked Oct 9, 2026 · toolgpa.com
Contents
- 01WelcomeWhat it is, who it suits, its grades and the ten things to know first
- 02What it costsEvery plan, the free plan, ways to pay less and how prices have moved
- 03What it doesIts main features, where it runs, what it works with and who makes it
- 04Where it standsIts grades against its category, and whether to keep it or make your own
- 05The alternativesThe tools it is most often weighed against, side by side
- 06Quick answersThe questions people ask about it, each answered in a line or two
- 07About ToolGPAWho made this guide, what else is on the site, and how to cite it
ToolGPA put this guide together from OneTask’s own pages, its app-store listings and our grades. Every fact in it is on OneTask’s page too, where it is kept up to date. Checked Oct 9, 2026.
Part 01 · Overview
Welcome
What it is, who it suits, its grades and the ten things to know first
2.8
GPA, above 92 of the 123 other to-do list apps we grade
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.
To get you started, here are 8 things to know about OneTask, taken from its own pages and our grades.
Two stores flag in-app purchases with no price shown anywhere, and its name changes from store to store.
- 1
Best for Google, Outlook and CalDAV tasks in one app
Without one of those accounts there's nothing in it, and there's no web version.
- 2
It is free
OneTask has no paid plan at all. 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.
- 3
It runs on 4 platforms
iOS, macOS, Windows and Android.
- 4
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.
- 5
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.
- 6
Subtasks, due dates and reminders
Tasks can carry subtasks, due dates and reminders, and widgets show tasks outside the app.
- 7
A 2.8 GPA, above 92 of 123
That is against the other to-do list apps we grade, on value, the free plan, features, ease of use and platforms.
- 8
Keep it
OneTask is free, so making your own would save you nothing.
OneTask at a glance
- Pricing
- Free
- Free plan
- Yes
- Free trial
- None stated
- Runs on
- macOS, Windows, iOS, Android
- Made by
- Code Spark, since 2016
- Category
- To-Do List Apps
- Our grade
- 2.8 GPA, good
The report card
Best for Google, Outlook and CalDAV tasks in one app
OneTask doesn't keep your tasks: it shows the ones you already have in Google Tasks, Outlook, iCloud Reminders or a CalDAV server like Nextcloud, side by side in one free app. Without one of those accounts there's nothing in it, and there's no web version. Two stores flag in-app purchases with no price shown anywhere, and its name changes from store to store.
| Subject | Grade | Comment |
|---|---|---|
| Value for money | A | A free download on the App Store, Google Play and the Microsoft Store, including the Mac and Windows apps, where this category's paid plans run $2.42 to $5.00 a month. Google Play and the Microsoft Store do flag in-app purchases, but no page shows a price for one. |
| Free plan and trial | A | The whole app, on all five platforms, for nothing, and the US App Store listing shows no in-app purchases at all. You bring your own Google, Microsoft, iCloud or CalDAV account and nothing is held back. |
| Features | D | It needs another product to do anything: the listing says it has no task service of its own, so without a Google, Microsoft, iCloud or CalDAV account there is nothing to show. What it adds is a viewer with sub-tasks, due dates, reminders, widgets, search and offline use. |
| Ease of use | C | No store rating on record, and the first thing it asks for is accounts: Google and Microsoft sign in with OAuth, while a CalDAV list wants a username, a password and a server address typed in. Nothing works until that's done. |
| Platforms and integrations | B | iPhone, iPad, Mac, Windows and Android, so phone and computer are both covered, and it connects to Google Tasks, Outlook, Office 365, iCloud Reminders, Nextcloud, Synology and Mailbox.org. The gap is the browser: there's no web version. |
An A is worth 4 points, a B 3, a C 2, a D 1 and an F nothing. The GPA is the average of the five.
Who OneTask is for
- Fits if your tasks are split between a Google account and a Microsoft one
- Works for Nextcloud or Synology users who want CalDAV tasks on phone and PC
Who it is not for
- Skip it if you want a to-do service of its own, because tasks live in the accounts you connect
- Not for you if you need your lists in a browser, as there's no web version
- Too light for anyone starting from scratch, since without an account to connect there's nothing in it
- Watch out: Google Play and the Microsoft Store flag in-app purchases, but no page shows a price for one
- Watch out: it's One Task on Google Play and the Microsoft Store and One Tasks on the App Store
Good to know
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.
Part 02 · Pricing
What it costs
Every plan, the free plan, ways to pay less and how prices have moved
Free
No paid plan at all
OneTask is free to use.
Google Play and the Microsoft Store do flag in-app purchases, but no page shows a price for one.
Free
$0
The full app on iPhone, iPad, Mac, Android and Windows, connected to the user's own task accounts.
The 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.
Read from apps.apple.com on Oct 9, 2026.
Part 03 · Features
What it does
Its main features, where it runs, what it works with and who makes it
4
Places it runs: macOS, Windows, iOS and Android
Free task app that syncs Google, Outlook and CalDAV task lists. Here is what it does, as its own site describes it, and what it covers: works offline, tasks.
What it adds is a viewer with sub-tasks, due dates, reminders, widgets, search and offline use.
- 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.
Where it runs
- macOS
- Windows
- iOS
- Android
What it works with
- Google Tasks
- Outlook
- Office 365
- iCloud Reminders
- OneCalendar
- Nextcloud
- Synology
- Mailbox.org
OneTask is made by Code Spark, and has been around since 2016.
Part 04 · Standing
Where it stands
Its grades against its category, and whether to keep it or make your own
92/123
Other to-do list apps it is graded above
OneTask's GPA of 2.8 is higher than 92 of the 123 other to-do list apps we grade, and level with 10.
It stands best on free plan and trial (A, above 87 of 123) and worst on features (D, above 0).
OneTask has no paid plan.
On features, ease of use and platforms it scores 2.0 out of 4. Nothing scores higher for less, though at least one tool matches that score at a lower price.
Each grade against the category
Every bar is all 124 to-do list apps we grade, cut by the letter each got. OneTask’s own letter is outlined.
- AValue for moneyAbove 69 of 123
- AFree plan and trialAbove 87 of 123
- DFeaturesAbove 0 of 123
- CEase of useAbove 10 of 123
- BPlatforms and integrationsAbove 73 of 123
Price against what you get
Each dot is one of 99 to-do list apps. Further left costs less; higher up scores better on features, ease of use and platforms. OneTask is the marked dot.
What paid plans start at, a month (each step along is roughly double) →
Keep it, or make your own?
Whether this is something you could build for yourself with an AI app builder, and what you would give up.
Keep it
OneTask is free, so making your own would save you nothing.
It is one of the better ones too: its GPA of 2.8 is higher than 92 of the 123 other to-do list apps we grade.
What you could make
- Tasks: an app builder makes this well.
What you could not
- Apps for macOS, Windows, iOS and Android that stay in step with each other.
- It plugs into other products, Google Tasks, Outlook and Office 365 among them.
- Hooks into the device itself: widgets.
What this rests on. OneTask’s listing: what it does, where it runs, what it plugs into and what it costs. It is a judgement about the kind of software this is. We have not built a replacement for it, and making your own means looking after it too. How we decide, and every tool’s verdict.
Part 05 · Alternatives
The alternatives
The tools it is most often weighed against, side by side
Tasks.org, Google Tasks, Microsoft To Do, 2Do and TasksBoard
The 5 tools OneTask is most often weighed against, with where each one differs from it.
- 3.4GPA
Tasks.org
Free plan · from $0.99/yr
Open-source Android to-do list with CalDAV and Google Tasks sync.
- Only OneTask lists an iOS app.
- Only Tasks.org lists a Linux app.
- Tasks.org is open source, according to its own site.
- 3.4GPA
Google Tasks
Free plan · from $7/mo
Google's to-do list, built into Gmail, Calendar, Chat and Docs.
- Only OneTask lists macOS and Windows apps.
- Only Google Tasks lists a web app.
- Google Tasks also covers time blocking and calendar.
- 3.6GPA
Microsoft To Do
Free
Free to-do list from Microsoft that syncs with Outlook tasks.
- Only Microsoft To Do lists a web app.
- 2.6GPA
2Do
Free plan · from $9.99 one-time
Task manager for Mac, iPhone, iPad and Android with no subscription.
- Only OneTask lists a Windows app.
- 2Do can be bought with a one-time purchase.
- 2Do also covers Markdown, natural-language input and calendar.
- 2.4GPA
TasksBoard
Free plan · from $3.99/mo
Full-screen kanban board and list sharing for Google Tasks.
- Only OneTask lists iOS, macOS, Windows and Android apps.
- Only TasksBoard lists a web app.
- Only TasksBoard lists a browser extension.
Part 06 · Questions
Quick answers
The questions people ask about it, each answered in a line or two
12
Questions, each answered in a line or two
The short version of everything above, for when you only need the answer. Each one is told in full in its part of the guide.
Is OneTask free?
Yes. OneTask is free to use.
How much does OneTask cost?
OneTask lists one plan. Free: $0.
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.
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.
How does OneTask compare with other to-do list apps?
OneTask's GPA of 2.8 is higher than 92 of the 123 other to-do list apps we grade, and level with 10.
Is OneTask good value for money?
ToolGPA grades OneTask A for value for money. OneTask has no paid plan.
Could I make my own version of OneTask?
OneTask is free, so making your own would save you nothing. It is one of the better ones too: its GPA of 2.8 is higher than 92 of the 123 other to-do list apps we grade.
Where this guide comes from
The prices, plans, platforms and features were read from OneTask’s own pages on Oct 9, 2026, and the grades were given on Oct 10, 2026. Graded from this listing, whose facts were read from OneTask's own pages on 9 October 2026. Also tested with a demo account on 2026-07-25.
Every tool we list gets five grades, A to F, each with its reason, and a GPA that averages them. How each is decided is at toolgpa.com/grades. This guide is ToolGPA’s own work; it is not made, paid for or approved by Code Spark. Prices change, so check onetask.eu before you buy.
- apps.apple.com/us/app/one-tasks/id1455000420
- onetask.eu/
- onetask.eu/download/store
- onetask.eu/onetask/about
- onetask.eu/onetask/privacypolicy
- onetask.eu/support/faq/about_security
- onetask.eu/support/faq/add-caldav-calendar
- play.google.com/store/apps/details?id=biz.codespark.onetask&hl=en_US&gl=US
- apps.microsoft.com/detail/9nblggh2jhrg?hl=en-US&gl=US
Part 07 · About
About ToolGPA
Who made this guide, what else is on the site, and how to cite it
3,189
Tools graded, in 94 categories
ToolGPA grades software the way a school report grades a pupil: five subjects, a letter for each with the reason written beside it, and a GPA that averages them. Prices, plans and platforms are read from each maker’s own pages and dated, so you always know how fresh a figure is.
Every grade, review and ranking on ToolGPA is our own judgement. No company can pay for a grade or change one. Every tool on the site has a guide like this one, free to download and pass on. It all lives at toolgpa.com.
3,189
tools graded
94
categories
426
price changes on record
579
apps priced in 12 countries
What else is on toolgpa.com
- OneTask, kept up to dateEverything in this guide, with prices and grades as they are todaytoolgpa.com/tools/onetask
- How grades are givenThe rules behind every letter and every GPAtoolgpa.com/grades
- Value chartsWhat each tool costs against what it scores, for every categorytoolgpa.com/charts
- CompareAny two tools side by side, plan by plantoolgpa.com/compare
- Price changesEvery price rise and cut on record, each with its sourcetoolgpa.com/price-changes
- Prices by countryWhat apps cost on the App Store in 12 countriestoolgpa.com/prices-by-country
- Pay lessEvery public discount: yearly billing, students, nonprofitstoolgpa.com/save
- Keep or makeWhich tools are worth paying for, and which you could build yourselftoolgpa.com/keep-or-make
Scan for the live page
Prices and grades as they are today
Quoting this guide?
Please name ToolGPA and link to the live page, so readers can check the figures for themselves:
ToolGPA, "OneTask: The Insider's Guide", checked Oct 9, 2026. https://toolgpa.com/tools/onetask
Know someone choosing between to-do list apps?
Send them this guide: toolgpa.com/tools/onetask/guide
ToolGPA elsewhere: youtube.com/@toolgpa
See our other guides
The best-graded to-do list apps after OneTask, each with an Insider's Guide of its own.
- To-Do List Apps Insider's GuideEvery one of the 124 to-do list apps we grade, compared
- Apple Reminders Insider's GuideApple's free to-do app for iPhone, iPad, Mac and Apple Watch3.6 GPA
- Microsoft To Do Insider's GuideFree to-do list from Microsoft that syncs with Outlook tasks3.6 GPA
- Google Tasks Insider's GuideGoogle's to-do list, built into Gmail, Calendar, Chat and Docs3.4 GPA
Choosing software? Every tool graded, every price dated.
Compare tools at toolgpa.com ›Everything in this guide is ToolGPA’s own summary of what OneTask’s pages, its app-store listings and public reviews said on the dates shown. Grades are our judgement under the rules at toolgpa.com/grades. Every grade, review and ranking on ToolGPA is our own judgement. No company can pay for a grade or change one. OneTask is a trademark of its owner, and this guide is not made, paid for or approved by Code Spark. Prices and plans change: check onetask.eu before you buy.