Free
Standard Numbers
Find four unique digits. Each clue separates exact matches from digits that belong elsewhere.
17 curated deduction games
Every clue gets you closer.
Crack hidden number and colour codes, learn what every clue rules in or out, and keep testing your theory until the machine opens.
Available for iPhone, iPad and Android. Free to start, with no adverts and no subscription.
17curated games
2always free
1pay once. keep forever
How to break a code
Guess. Read the clues. Deduce.
Each attempt tells you something useful. The trick is turning that information into a better next guess.
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01
Build a guess
Fill every position with a number, colour or symbol allowed by that game.
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02
Read the feedback
Clues tell you what is exactly placed, what belongs elsewhere—or only what that twist permits you to know.
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03
Crack the code
Lock strong deductions, rule impossible symbols out and solve before your attempts—or time—run out.
A machine built for deduction
Keep the whole theory in front of you.
The board keeps earlier guesses and their clues visible while the controls beneath it help you manage what you have learned.
- Tap or drag symbols straight into position
- Lock a confirmed symbol into later guesses
- Cross impossible digits or colours off the keypad
- Add scratchpad notes without leaving the puzzle
- Open the exact rules for the game at any time
All 17 challenges explained
Change one rule. Change the whole deduction.
Start with the two classics, then change the symbols, clue system, pressure or information available. The curated rules stay fixed so every player faces the same challenge.
Free
Standard Colours
Crack a four-peg colour code. Colours may repeat, with exact and misplaced clues after every guess.
Blank Pegs
An empty position becomes a real symbol, so absence itself may be part of the code.
No-Repeats Colours
The colour classic with duplicates forbidden in both the secret code and your guesses.
Repeating Numbers
Classic number deduction, except a digit can occupy more than one position.
Super Colours
A broader palette expands the possible codes without changing the familiar clue language.
Mini Colours
A compact colour puzzle with only eight attempts for a faster, more focused challenge.
Five-Slot Colours
One extra hidden peg turns the familiar colour puzzle into a much deeper deduction.
Pico Fermi Bagels
Fermi means exact, Pico means misplaced and Bagels means no digit matched at all.
Number Permutation
All six digits from 0 to 5 appear exactly once. Discover their hidden order.
Exact-Only
You learn how many symbols are perfectly placed, while misplaced matches stay secret.
Misplaced-Only
Clues reveal symbols that belong elsewhere while withholding exact-position information.
Total Matches
Exact and misplaced matches are merged into one total for you to separate.
Positional Feedback
Feedback attaches to individual slots rather than arriving as an aggregate score.
Endless
Break one code after another and see how long your successful streak can continue.
Fog of War
Earlier guesses fade from view, turning memory into part of the challenge.
Time Attack
Solve the standard deduction race against a hard time limit.
Numbers or colours
Same core idea. A completely different feel.
Move between numerical logic and a tactile colour board without learning a new interface. Named colours and distinct symbols keep the clues readable without relying on colour alone.
Ultimate Designer
Your machine. Your rules.
Build a challenge around the deductions you enjoy, play it immediately or save it to My Games for another day.
- 1Choose the code
Use numbers or colours, set the positions and choose how many symbols are available.
- 2Choose the clues
Use standard totals, exact-only, misplaced-only, total matches or positional feedback.
- 3Add pressure
Allow repeats, limit attempts, start a timer or hide all but the latest guesses.
- 4Play or save
Name the design, duplicate it later and keep separate statistics for each rules revision.
Fair by design: custom games stay local and do not enter public leaderboards because custom difficulties are not directly comparable.
Measure your mastery
See where your deductions improve.
Track games played, codes broken, success rate, solve time, best time and streaks overall, by category and by individual game.
- Separate number and colour performance
- Per-game results for every curated challenge
- Per-design statistics for saved custom games
- Supported platform leaderboards for comparable curated modes
Permanent upgrades
Start free. Pay once if you want more.
No subscription and no adverts. Apple and Google show the final local price before purchase.
Free
£0
Two complete classics and a rotating taste of the wider collection.
- Standard Numbers
- Standard Colours
- One complete featured premium round each day
- Core deduction tools and statistics
Ultimate
£4.99 once
Every curated way to break a code, permanently unlocked.
- All 17 curated games
- Future curated code-breaking games
- Unlimited play
- Eligible platform leaderboards
Complete collection
Ultimate Designer
£7.99 once
Everything in Ultimate plus your own code-breaking studio.
- Everything in Ultimate
- Create, name and save custom games
- Edit and duplicate designs
- Statistics for every saved game
Already own Ultimate? Add Designer for £2.99.
Private by design
Play without making an account.
Your settings, scratchpad, saved designs and local statistics stay on your device. Ultimate Code Breaker has no adverts, third-party analytics or Technova account system.
Read the privacy policy
The machine is waiting
What will your first clue reveal?
Start with two classic games for free on iPhone, iPad or Android.