21 Black vs ChaosFour
Price, ratings, monetisation and update history for both games, side by side — with what reviewers say about each.
21 Black
A brain training puzzle game where you merge cards horizontally or vertically to reach a sum of 21. Features endless and puzzle modes with unlimited hints and no time limits.
- Card merging gameplay
- Endless mode
- Puzzle mode with custom sizes
- Share and scan puzzles
- Unlimited free hints
- No time limits
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21 Black is a challenging puzzle game that mixes solitaire and blackjack. Your goal is simple: merge the cards to make 21. How far will you get? 21 Black Features SIMPLE GAMEPLAY Swipe to merge the cards horizontally or vertically, different numbers add up while identical numbers stay the same. Get to 21 and win! ENDLESS MODE Relax in endless mode and see how many 21's can you make PUZZLE MODE Choose from multiple puzzle sizes and collapse the entire board into a single 21. Perfect for training your brain to recognize patterns and build new strategies. SHARE + DISCOVER Played a cool puzzle? Share it with your friends and the world! Or scan puzzles other's have discovered with the built in puzzle camera scanner! NO STRESS Unlimited free hints and no time limits means you can relax and get into a flow 100% FREE That's right, everything is unlocked and there is nothing to purchase Fun and addicting gameplay that's guaranteed to test and train your brain in new ways! Questions? Please contact us at contact@bitfreegames.com
ChaosFour
A twist on the classic four-in-a-row game where random mini-games can disrupt your strategy. Lose a mini-game, and a disc is removed, adding a chaotic element to every turn. Play against a friend or a challenging bot.
- Four-in-a-row gameplay
- Random mini-game challenges
- Disc removal mechanic
- Play against AI bot
- Local multiplayer mode
- Unpredictable gameplay
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Chaos Four is four in a row with a chaotic twist. Every turn, there is a small chance that you might have to play a mini-game: coin flip, trivia, math, a tiny bird game, and a bunch of others. If you lose the mini-game, one of your discs, selected randomly, is deleted. Gravity is applied, win conditions are checked, and the game continues. This game mechanic is the Chaos. Four in a row is a solved game. This means that if both players play a perfect game, a win is guaranteed to the first player. Chaos Four is not a solved game. This is due to the Chaos. Even the Hard Bot, which plays a perfect game, can lose. So can you. Free to download, no ads. Play with a friend, or against the Bot.
Screenshots
Verdict
The clearest difference is in-app purchases: 21 Black at none against ChaosFour's 1. 21 Black also leads on iOS requirement (8.0 vs 18.2). ChaosFour's advantage is update cadence (every 10 days vs every 15 months) and rating (5.0 vs 4.8). On price, review sentiment, ratings volume and ads there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. ChaosFour sells 1 one-off in-app purchase. 21 Black asks for nothing beyond the download.
ChaosFour holds the better App Store score, 5.0 against 4.8. Both are backed by a comparable volume of ratings — 5 and 5 respectively. Written reviews split almost evenly too, at 100% and 100% positive.
21 Black ships an update every 15 months, ChaosFour every 10 days. The most recent releases landed on October 24, 2026 and October 6, 2026 respectively.
| Parameter | 21 Black | ChaosFour |
|---|---|---|
| Price | Free | Free |
| Rating | 4.8 (5 ratings) | 5.0 (5 ratings) — better |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Number of ratings | 5 | 5 |
| Update frequency | Every 15 months | Every 10 days — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 8.0 — better | 18.2 |
| Further details — not scored | ||
| Size | 48 MB | 94 MB |
| Age rating | 4+ | 12+ |
| Developer | Bit Free Games | Spicy Deep Fried Games |
Customer experience
21 Black
ChaosFour
In-app purchases
21 Black
No in-app purchases
ChaosFour
- Premium$0.99
Questions
Is 21 Black free?
Is ChaosFour free?
Which has better reviews, 21 Black or ChaosFour?
Do 21 Black or ChaosFour have ads?
Which is updated more often, 21 Black or ChaosFour?
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