Sudoku - Classic Puzzle Game

Privacy Policy

Version 2026-08-11. Effective 11 August 2026.

Who is responsible

I run Sudoku personally, not as a company, so the person responsible for everything here is me, Edvin Lindén. Write to hello@edvinlinden.se.

If you email me, your message and address stay in my email archive. Nothing goes on a mailing list, nothing is shared, and I'll delete a message on request.

What Sudoku collects

Sudoku collects usage analytics. With analytics switched on, this is what is collected:

An identifier for your installation of Sudoku. It cannot be traced back to you, and it cannot be matched against any other app, including my own.

When it happened. An identifier for the current session, and the date and time.

What happened. Every event Sudoku sends:

• your first session after installing the app
• a session starting
• finishing the first-launch introduction, and which of its three routes you took
• starting a new puzzle, with the difficulty
• resuming a puzzle you had already started
• completing a puzzle, with the difficulty and how long it took
• giving up on a puzzle by starting another one, with the difficulty, how long you played and how far through it you got

How many puzzles you have solved. The number, attached to every one of the events above.

What the app is running on. The device model, operating system, screen size, language, region and time zone, whether the app is in light or dark mode, its version, and whether it came from the App Store or from a test build.

How much you use the app. The date you first used it, how many sessions you have had, how long they last, and how many days you have opened it.

Technical details of the analytics software, such as its version.

What Sudoku keeps on your device

Analytics keeps a small record of when you have opened the app, which is what the usage counts above are worked out from. Events waiting to be sent are held on the device too, until they're delivered. Turning analytics off deletes both. If you never turn analytics on, it is never written.

Sudoku also stores your analytics decision: whether it is on or off, when and how you decided, the version of this policy in force at the time, and the country of your App Store account. The country decides whether you have to be asked for consent, and is never sent anywhere.

What Sudoku syncs through your iCloud

Your puzzles in progress, your statistics and your settings are stored on your device. If iCloud sync is on — it is on by default, and there is a switch for it under More, then Settings — they are also stored in your own iCloud account, so you can start a puzzle on one device and finish it on another.

That sync goes between your devices and Apple's servers. It does not go to me, and I have no access to it. Apple's handling of it is covered by Apple's privacy policy, not this one.

Nothing about your puzzles or statistics is sent to me, with one exception, which is stated above and worth repeating plainly: the analytics events include the difficulty of a puzzle you start, finish or give up on, how long a puzzle took, how many of its squares you had filled in when you gave up, and how many puzzles you have solved in total. The boards themselves, your notes and your entries are never sent.

What Sudoku doesn't collect

No name, email or account, because Sudoku has no accounts. No advertising identifier, no ad networks. No tracking across other companies' apps or websites. No GPS or location services data. Nothing about your accessibility settings. I do not sell data or share it with advertisers or brokers.

Nothing here is used to make automated decisions about you, and nothing builds a profile of you. The data answers questions about groups of players, not about individuals.

Why Sudoku collects this data

Three reasons, and no others:

1. Checking a release works, by seeing whether the app is still used normally afterwards.
2. Seeing which features people find and use, and whether the difficulty levels are graded sensibly, so I know what to improve.
3. Counting users by country, to decide which languages to translate into.

In the European Economic Area the legal basis is your consent, Article 6(1)(a) GDPR. Sudoku asks first, sends nothing until you say yes, and you can withdraw any time. Everywhere else it is my legitimate interests, Article 6(1)(f), those interests being the three purposes above, and analytics is on by default with a switch to turn it off.

Opting out

The switch is under More and then Privacy, in the same place whether you were asked for consent or not. Turning it off ends collection immediately, deletes anything that had not yet been sent, and deletes what analytics had stored on your device. Sudoku works the same with analytics off. Withdrawing consent does not make what was collected beforehand unlawful, it only stops collection from that point.

Turning it back on records a fresh decision against the current policy version.

Where the data goes and how long it stays

Data goes to TelemetryDeck GmbH in Augsburg, Germany, which provides the analytics service. Their privacy policy is at https://telemetrydeck.com/privacy.

TelemetryDeck stores it in the EU and does not transfer it outside the EU or the EEA. TelemetryDeck keeps it available for 24 months, and after that moves it to cold storage rather than deleting it.

Your rights

You have the right to access your data, correct it, delete it, restrict its use, object to its use, receive a copy, and withdraw your consent. Email me.

The analytics data holds nothing that identifies you, so I can't find your records in it. Article 11 GDPR doesn't require me to start collecting more about you to make that possible, and I won't. What I can do is stop collecting from you, which is what the switch above does.

You have the right to lodge a complaint with the Swedish data protection authority, Integritetsskyddsmyndigheten (IMY), or with the supervisory authority where you live.

Changes

This policy may be updated. Changes are published on this page with a new effective date.