The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 7 days. Why not try and solve them ahead of time?
Kaprekar Numbers in all languages in bytes. Achievements Cheevos Holes Languages Medals Miscellaneous All Holes 12 Days of Christmas 24 Game 99 Bottles of Beer Abundant Numbers Abundant Numbers (Long) Arabic to Roman Arithmetic Numbers Arrows Ascending Primes ASCII Table Billiards brainfuck Calendar Card Number Validation Catalan Numbers Catalan’s Constant Christmas Trees Collatz Continued Fractions CSS Colors Cubes Day of Week DFA Simulator Diamonds Divisors Emirp Numbers Emirp Numbers (Long) Emojify Evil Numbers Evil Numbers (Long) Factorial Factorisation Farey Sequence Fibonacci Fizz Buzz Foo Fizz Buzz Bar Forsyth–Edwards Notation Fractions Game of Life Gijswijt’s Sequence Happy Numbers Happy Numbers (Long) Hexdump Hilbert Curve Intersection Inventory Sequence ISBN Jacobi Symbol Kaprekar Numbers Kolakoski Constant Kolakoski Sequence Leap Years Levenshtein Distance Leyland Numbers ln 2 Look and Say Lucky Numbers Lucky Tickets Mahjong Mandelbrot Maze Medal Tally Minesweeper Morse Decoder Morse Encoder Multitap Input Musical Chords N Queens Niven Numbers Niven Numbers (Long) Number Spiral Odious Numbers Odious Numbers (Long) Ordinal Numbers PalindromemordnilaP Pangram Grep Partition Numbers Pascal’s Triangle Pernicious Numbers Pernicious Numbers (Long) Poker Polyominoes Prime Numbers Prime Numbers (Long) Proximity Grid QR Decoder Quine Recamán Repeating Decimals Reverse Polish Notation Reversi Rijndael S-box Rock-paper-scissors-Spock-lizard Roman to Arabic ROT13 Rule 110 Scrambled Sort Set Seven Segment SI Units Sierpiński Triangle Smith Numbers Spelling Numbers Star Wars GPT Star Wars Opening Crawl Sudoku Sudoku (Fill-in) Ten-pin Bowling Tic-tac-toe Time Distance Tongue-twisters Topological Sort Tower of Hanoi Transpose Sentence Trinomial Triangle United States Vampire Numbers Van Eck Sequence Zeckendorf Representation Zodiac Signs γ λ π τ φ √2 𝑒 Alphabetic Numbers Apéry’s Constant Binary Lambda Calculus Connect Four Crossword CSS Colors (Inverse) CSS Grid Ellipse Perimeters Flags Floyd-Steinberg Dithering Gray Code Decoder Gray Code Encoder Hexagonal Spiral Highly Composite Numbers NFA Simulator Numbrix Odd Polyomino Tiling p-adic Expansion Polygon Triangulations QR Encoder Quadratic Formula Rectangle Fill Semiprime Numbers Smooth Numbers Snake Sphenic Numbers Taxicab Numbers Turtle Tutorial All Languages ><> ALGOL 68 ArkScript Assembly AWK Bash BASIC Berry brainfuck C C# C++ Civet Clojure COBOL Coconut Common Lisp Crystal D Dart Elixir Erlang F# Factor Forth Fortran Gleam Go GolfScript Groovy Haskell Hexagony J Janet Java JavaScript jq Julia K Kotlin Lua Nim OCaml Pascal Perl PHP PowerShell Prolog Python R Raku Rockstar Ruby Rust Scheme sed SQL Swift Tcl TeX V VimL Wren Zig 05AB1E APL Arturo Befunge BQN CJam CoffeeScript Egel Fennel Harbour Hare Haxe Hush Hy iogii Knight Lily Luau Odin Picat Qore Racket Rebol Rexx Scala Squirrel Stax Uiua Umka Vala Vyxal Bytes Chars Scoring Bytes Chars Language All ><> ALGOL 68 ArkScript Assembly AWK Bash BASIC Berry brainfuck C C# C++ Civet Clojure COBOL Coconut Common Lisp Crystal D Dart Elixir Erlang F# Factor Forth Fortran Gleam Go GolfScript Groovy Haskell Hexagony J Janet Java JavaScript jq Julia K Kotlin Lua Nim OCaml Pascal Perl PHP PowerShell Prolog Python R Raku Rockstar Ruby Rust Scheme sed SQL Swift Tcl TeX V VimL Wren Zig Experimental Language 05AB1E APL Arturo Befunge BQN CJam CoffeeScript Egel Fennel Harbour Hare Haxe Hush Hy iogii Knight Lily Luau Odin Picat Qore Racket Rebol Rexx Scala Squirrel Stax Uiua Umka Vala Vyxal Hole All 12 Days of Christmas 24 Game 99 Bottles of Beer Abundant Numbers Abundant Numbers (Long) Arabic to Roman Arithmetic Numbers Arrows Ascending Primes ASCII Table Billiards brainfuck Calendar Card Number Validation Catalan Numbers Catalan’s Constant Christmas Trees Collatz Continued Fractions CSS Colors Cubes Day of Week DFA Simulator Diamonds Divisors Emirp Numbers Emirp Numbers (Long) Emojify Evil Numbers Evil Numbers (Long) Factorial Factorisation Farey Sequence Fibonacci Fizz Buzz Foo Fizz Buzz Bar Forsyth–Edwards Notation Fractions Game of Life Gijswijt’s Sequence Happy Numbers Happy Numbers (Long) Hexdump Hilbert Curve Intersection Inventory Sequence ISBN Jacobi Symbol Kaprekar Numbers Kolakoski Constant Kolakoski Sequence Leap Years Levenshtein Distance Leyland Numbers ln 2 Look and Say Lucky Numbers Lucky Tickets Mahjong Mandelbrot Maze Medal Tally Minesweeper Morse Decoder Morse Encoder Multitap Input Musical Chords N Queens Niven Numbers Niven Numbers (Long) Number Spiral Odious Numbers Odious Numbers (Long) Ordinal Numbers PalindromemordnilaP Pangram Grep Partition Numbers Pascal’s Triangle Pernicious Numbers Pernicious Numbers (Long) Poker Polyominoes Prime Numbers Prime Numbers (Long) Proximity Grid QR Decoder Quine Recamán Repeating Decimals Reverse Polish Notation Reversi Rijndael S-box Rock-paper-scissors-Spock-lizard Roman to Arabic ROT13 Rule 110 Scrambled Sort Set Seven Segment SI Units Sierpiński Triangle Smith Numbers Spelling Numbers Star Wars GPT Star Wars Opening Crawl Sudoku Sudoku (Fill-in) Ten-pin Bowling Tic-tac-toe Time Distance Tongue-twisters Topological Sort Tower of Hanoi Transpose Sentence Trinomial Triangle United States Vampire Numbers Van Eck Sequence Zeckendorf Representation Zodiac Signs γ λ π τ φ √2 𝑒 Experimental Hole Alphabetic Numbers Apéry’s Constant Binary Lambda Calculus Connect Four Crossword CSS Colors (Inverse) CSS Grid Ellipse Perimeters Flags Floyd-Steinberg Dithering Gray Code Decoder Gray Code Encoder Hexagonal Spiral Highly Composite Numbers NFA Simulator Numbrix Odd Polyomino Tiling p-adic Expansion Polygon Triangulations QR Encoder Quadratic Formula Rectangle Fill Semiprime Numbers Smooth Numbers Snake Sphenic Numbers Taxicab Numbers Turtle Tutorial # Golfer Points Bytes Time Submitted 881st KatieLG 🇬🇧 146 538 491ms 1 Nov 2024 882nd JunkIce 145 449 640ms 3 Dec 2024 883rd Maznek 144 364 13ms 8 Nov 2024 883rd elisherer 🇮🇱 144 364 9ms 3 Nov 2025 885th HumanoidCPU 144 452 348ms 1 Nov 2024 885th Shanethegamer 🇺🇸 144 452 367ms 1 Nov 2024 885th JOrE20 144 452 353ms 2 Feb 2026 888th HumanoidCPU 144 461 112ms 1 Nov 2024 888th KatieLG 🇬🇧 144 461 118ms 1 Nov 2024 888th Shanethegamer 🇺🇸 144 461 123ms 1 Nov 2024 888th MeWhenI 🇻🇦 144 461 110ms 2 Nov 2024 888th CaedenHarper 🇨🇦 144 461 110ms 24 Jan 2025 893rd KatieLG 🇬🇧 143 469 5ms 30 Nov 2025 894th KatieLG-Transpiler 🇬🇧 143 528 379ms 9 Jan 2026 895th HumanoidCPU 141 446 72ms 1 Nov 2024 895th Shanethegamer 🇺🇸 141 446 72ms 1 Nov 2024 895th MeWhenI 🇻🇦 141 446 75ms 2 Nov 2024 895th snoozingnewt 🇨🇦 141 446 74ms 3 Nov 2024 895th CaedenHarper 🇨🇦 141 446 73ms 16 Aug 2025 900th KatieLG-Transpiler 🇬🇧 140 564 148ms 9 Jan 2026 901st dokutan 139 452 84ms 1 Nov 2024 902nd KatieLG 🇬🇧 138 505 640ms 30 Nov 2025 903rd emgordon154 138 602 2,205ms 12 Dec 2024 904th HumanoidCPU 137 575 41ms 9 Mar 2025 905th KatieLG 🇬🇧 135 465 73ms 30 Nov 2025 906th dokutan 134 473 1ms 1 Nov 2024 907th KatieLG 🇬🇧 133 475 1ms 1 Nov 2024 908th dokutan 133 591 38ms 1 Nov 2024 909th KatieLG-Transpiler 🇬🇧 132 505 114ms 9 Jan 2026 910th KatieLG-Transpiler 🇬🇧 132 515 139ms 9 Jan 2026 911th KatieLG-Transpiler 🇬🇧 132 519 9ms 9 Jan 2026 912th KatieLG 🇬🇧 131 443 3ms 30 Nov 2025 913th HumanoidCPU 131 444 2ms 1 Nov 2024 913th Shanethegamer 🇺🇸 131 444 2ms 1 Nov 2024 913th dokutan 131 444 3ms 1 Nov 2024 913th MeWhenI 🇻🇦 131 444 2ms 2 Nov 2024 913th CaedenHarper 🇨🇦 131 444 3ms 16 Aug 2025 913th JRaspass 🇬🇧 131 444 3ms 63 mins ago 919th KatieLG-Transpiler 🇬🇧 131 446 3ms 9 Jan 2026 920th dokutan 131 483 1ms 21 Jun 2025 921st KatieLG-Transpiler 🇬🇧 131 512 4ms 9 Jan 2026 922nd KatieLG-Transpiler 🇬🇧 131 533 648ms 9 Jan 2026 923rd KatieLG 🇬🇧 130 487 1ms 30 Nov 2025 924th KatieLG 🇬🇧 130 515 2ms 8 Jan 2025 924th KatieLG-Transpiler 🇬🇧 130 515 1ms 9 Jan 2026 926th KatieLG-Transpiler 🇬🇧 128 528 1ms 9 Jan 2026 927th sciencejiho 127 532 2ms 12 Feb 2025 928th KatieLG-Transpiler 🇬🇧 125 519 380ms 9 Jan 2026 929th HumanoidCPU 123 446 1,278ms 1 Nov 2024 929th Shanethegamer 🇺🇸 123 446 1,285ms 1 Nov 2024 929th dokutan 123 446 1,302ms 1 Nov 2024 929th CaedenHarper 🇨🇦 123 446 1,311ms 24 Jan 2025 933rd MeWhenI 🇻🇦 123 515 1ms 2 Nov 2024 933rd CaedenHarper 🇨🇦 123 515 2ms 12 Nov 2025 933rd Shanethegamer 🇺🇸 123 515 1ms 12 Nov 2025 933rd HumanoidCPU 123 515 1ms 12 Nov 2025 937th KatieLG-Transpiler 🇬🇧 122 517 73ms 9 Jan 2026 938th HumanoidCPU 122 518 1ms 1 Nov 2024 938th Shanethegamer 🇺🇸 122 518 1ms 1 Nov 2024 938th MeWhenI 🇻🇦 122 518 2ms 2 Nov 2024 938th CaedenHarper 🇨🇦 122 518 1ms 22 Jan 2025 942nd KatieLG-Transpiler 🇬🇧 122 519 1ms 9 Jan 2026 943rd KatieLG-Transpiler 🇬🇧 121 525 1ms 9 Jan 2026 944th dokutan 120 439 33ms 21 Apr 2025 944th olleicua 🇺🇸 120 439 35ms 12 Jun 2025 946th HumanoidCPU 119 445 35ms 1 Nov 2024 946th Shanethegamer 🇺🇸 119 445 38ms 1 Nov 2024 946th CaedenHarper 🇨🇦 119 445 34ms 16 Aug 2025 949th Shanethegamer 🇺🇸 119 453 125ms 1 Nov 2024 949th KatieLG 🇬🇧 119 453 150ms 1 Nov 2024 949th MeWhenI 🇻🇦 119 453 128ms 2 Nov 2024 949th CaedenHarper 🇨🇦 119 453 135ms 24 Jan 2025 953rd KatieLG 🇬🇧 119 461 1,221ms 30 Nov 2025 954th HumanoidCPU 118 446 10ms 1 Nov 2024 954th dokutan 118 446 10ms 1 Nov 2024 954th MeWhenI 🇻🇦 118 446 8ms 2 Nov 2024 954th zakariamouhid 118 446 8ms 17 Nov 2024 954th Salutations45 118 446 9ms 22 Nov 2024 954th gigaprofisi 🇺🇸 118 446 9ms 20 Jun 2025 954th didion0 🇺🇸 118 446 9ms 26 Aug 2025 First Prev 881–960 of 1,111 Next Last
