Comparison

Sudoku vs Quiet Letters

Price, ratings, monetisation and update history for both games, side by side โ€” with what reviewers say about each.

Head to head
About

Sudoku

Features
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Enjoy a little problem-solving on your commute, on a trip, or during a daily break with Sudoku - Notes Games. Play classic 9ร—9 number puzzles offline, with a cute puppy for company. โ€ข Pick easy grids for a relaxed session or hard challenges when you want to think a little longer. Choose a difficulty that suits you, from beginner to experienced player. โ€ข Keep track of possible numbers with notes and pencil marks, then use logic to work out your next move. Each puzzle you solve earns paws you can use to collect dog avatars. Finish a grid, enjoy the achievement, and work toward the next addition to your collection.

About

Quiet Letters

Features
Read full description

Quiet Letters is a calm word-puzzle game. Each round you have a fixed number of guesses to find the hidden word. Tiles light up to tell you which letters belong, which are misplaced, and which are out. No timer, no streak penalty, no noise โ€” just letters and time to think. Three modes: โ€ข Mini โ€” 4 letters, 5 guesses. A short break. โ€ข Classic โ€” 5 letters, 6 guesses. The puzzle you know. โ€ข Wide โ€” 6 letters, 7 guesses. A slower read. Each mode plays Daily (one shared puzzle per day) or Practice (unlimited rolls), with an optional Hard mode that locks in revealed letters. Seven languages, each with its own keyboard and word list: English, French, Spanish, German, Italian, Portuguese, Dutch. Five themes โ€” Light, Dark, Paper, Dusk, and a colour-blind-friendly Accessible palette โ€” plus shape marks on every tile so the game stays readable for every kind of vision. Soft ambient music and gentle haptics. Every sound has a tap-mute on the Home screen, no settings dive needed. An optional daily reminder nudges you back at the time you choose. No ads. No tracking. No accounts. Your stats live on this device only.

Screenshots

Sudoku3 screens
Quiet Letters4 screens

Verdict

The call

The clearest difference is in-app purchases: Quiet Letters at none against Sudoku's 2. Quiet Letters also leads on ads (none vs shown). Sudoku's advantage is update cadence (every 3 days vs every 3 weeks). On price, device support and iOS requirement there is nothing between them.

Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS

CostPrice ยท In-app purchases ยท Ads ยท Monetization

Both are free to download. Sudoku sells 2 one-off in-app purchases. Quiet Letters asks for nothing beyond the download.

UpkeepUpdate frequency

Sudoku ships an update every 3 days, Quiet Letters every 3 weeks. The most recent releases landed on October 28, 2026 and October 31, 2026 respectively.

Scorecard3 real differences ยท 3 level
Sudoku versus Quiet Letters: the parameters behind the verdict, then further details
ParameterSudokuQuiet Letters
PriceFreeFree
Update frequencyEvery 3 days โ€” betterEvery 3 weeks
AdsYesNo โ€” better
In-app purchasesYesNo โ€” better
DevicesiPhone, iPadiPhone, iPad
Requires iOS16.0 โ€” better17.0
Further details โ€” not scored
Size147 MB44 MB
Age rating4+4+
DeveloperKUO CHENG-YENLaurent Chouinard

In-app purchases

2 purchases

Sudoku

One-time2
  • bone$0.99
  • Unlock perks$2.99
None

Quiet Letters

No in-app purchases

Questions

Is Sudoku free?
Sudoku is free to download, with in-app purchases available.
Is Quiet Letters free?
Quiet Letters is free to download, with no in-app purchases.
Do Sudoku or Quiet Letters have ads?
Sudoku shows ads; Quiet Letters does not.
Which is updated more often, Sudoku or Quiet Letters?
Sudoku ships an update every 3 days, and Quiet Letters every 3 weeks. Most recently, Sudoku was updated on October 28, 2026 and Quiet Letters on October 31, 2026.

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