Frequently Asked Questions

How do I enter a number?

Tap a cell to select it, then tap a digit on the number pad — or just type the number on your keyboard. Tap the same digit again, or the eraser, to clear the cell.

What is Notes (pencil) mode?

Notes mode lets you pencil in small candidate digits in a cell while you work out the answer. Turn on the pencil/Notes button, tap digits to add or remove candidates, then turn it off to enter your final answer.

How do I erase a cell?

Select the cell and tap the eraser, or tap the same number again. Starting clues are locked and cannot be erased.

What are hints and how many do I get?

A hint reveals the correct value of the selected cell. Free games include a limited number of hints per difficulty, shown as a countdown. A cell you reveal with a hint does not earn points.

What are jokers / power-ups?

Jokers are one-time boosts you can use during a game: Reveal Row fills an entire row, Freeze Timer stops the clock for 60 seconds, and Solve Box fills a 3×3 box. You earn or buy them with coins in the Shop.

Does the timer keep running when I pause?

No. The timer only counts your active solving time. Pausing the game stops the clock, and time spent away or after a refresh does not count.

What does New Game do?

New Game instantly clears the board and generates a fresh puzzle of the selected type and difficulty.

What happens if I make a mistake?

The app tracks your mistakes during a game. Conflicting or incorrect entries are highlighted so you can spot and fix them.

Can I use the keyboard?

Yes. Use the number keys 1–9 to fill the selected cell, arrow keys to move between cells, and Backspace or Delete to clear a cell.

Can I share or replay the exact same puzzle?

Yes. Every puzzle has its own shareable link (a game code), so you can replay it later or send the identical puzzle to a friend.

Is my game saved if I leave or refresh?

Yes. Your current game is saved automatically in your browser, so you can refresh or come back later and resume where you left off.

What difficulty levels are there?

There are five levels: Easy, Medium, Hard, Expert and Evil. Higher levels start with fewer given numbers and need more advanced solving techniques.

Which difficulty should I pick?

Easy and Medium are great for relaxing or learning. Hard, Expert and Evil are for experienced solvers who enjoy advanced techniques.

Do harder puzzles ever require guessing?

No. Every puzzle at every difficulty has a single unique solution reachable by logic alone.

What is the Daily Challenge?

Every day there is a fresh set of daily puzzles — one each in Easy, Medium and Hard. Everyone plays the same daily puzzles, so you can compare your times.

How do daily challenges affect my streak?

Completing a daily puzzle keeps your daily streak going. Play every day to build a longer streak.

Can I play past daily challenges?

You can revisit the daily archive to play challenges from previous days.

Are there rewards for daily challenges?

Yes. Completing every day of a month earns special monthly achievements, and finishing all three difficulties for a whole month earns a bonus achievement.

What is a streak?

Your streak is the number of consecutive days you complete at least one puzzle. The app tracks both your current streak and your longest ever streak.

What are achievements?

Achievements are badges you unlock for milestones — games completed, streaks, fast solves, perfect (mistake-free) games, mastering game types, daily challenges and special feats. Each achievement also grants coins.

How do I earn coins from achievements?

Every achievement awards a set number of coins when you unlock it, on top of the coins you earn for completing games.

Where do I see my achievements?

Open your Profile to see the full achievement catalogue, with the ones you have earned shown in colour and the rest greyed out with a description and the reward they grant.

How does the leaderboard work?

The global leaderboard ranks registered players by total points, longest streak or games completed. You can switch between these with the tabs.

Do I need an account to be on the leaderboard?

Yes. The leaderboard ranks registered players. Create a free account to claim your place — anonymous play is not listed on the leaderboard.

I am not in the top — can I see my rank?

Yes. If you are outside the visible top list, your own position is still shown in a separate card so you always know where you stand.

How do I earn coins?

You earn coins by completing puzzles and by unlocking achievements.

What can I spend coins on?

You can spend coins in the Shop on jokers (Reveal Row, Freeze Timer, Solve Box) and hint packs.

Do coins cost real money?

No. Coins are an in-game currency you earn by playing — they are not purchased with real money.

Why do I see ads?

Ads help keep SudokuStreak free for everyone. You can manage your cookie preferences from the cookie banner at any time.

Can I remove the ads?

A paid ad-free option is planned. For now the game is fully playable for free with ads.

Do I need an account to play?

No. You can play instantly without signing up. Your progress is saved in your browser, and you even get an anonymous profile name and avatar.

Why should I create an account?

An account puts you on the leaderboard under your own name, keeps your coins and achievements, syncs across devices, and protects your progress if you clear your browser. Your Sparks total from anonymous play carries over when you sign up.

How do I sign in?

You sign in with your email and password.

Can I export or delete my data?

Yes. From your Profile you can export all your data as a file, or permanently delete your account. We follow GDPR for personal data.

What data do you store for anonymous players?

Anonymous progress is stored in your browser, plus a minimal anonymous profile — a name, avatar and your Sparks total — so your chosen identity can be shown next to puzzle records. Anonymous players are not listed on the leaderboard.

Can I print Sudoku puzzles?

Yes. Use the Print page to generate free printable PDF puzzles to solve on paper.

Can I print different types and difficulties?

Yes. You can choose the game type and difficulty, and optionally include the solutions, before downloading the PDF.

Is SudokuStreak free?

Yes, SudokuStreak is free to play. You can enjoy every game type and the daily challenges without paying.

Does it work on mobile?

Yes. The game works in any modern browser on phones, tablets and computers — no app install required.

Do the puzzles always have one solution?

Yes. Every puzzle is generated to have exactly one unique solution that can be found with logic.

My game looks stuck or out of date — what can I do?

Refresh the page. Your current game is saved, so you will not lose progress.