The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 2 days. Why not try and solve them ahead of time?
Kolakoski Sequence 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 MeWhenI 🇻🇦 685 72 312ms 15 Feb 2023 881st Yewzir 🇧🇪 685 72 398ms 5 Apr 2024 883rd msbranicky 685 89 2ms 26 Sep 2023 884th DialFrost 🇸🇬 684 67 154ms 3 Aug 2024 885th madex 🇩🇪 684 79 2ms 11 Jul 2024 886th AdrienHache 🇫🇷 683 41 48ms 23 Oct 2023 887th CaedenHarper 🇨🇦 682 36 51ms 17 days ago 888th Yewzir 🇧🇪 682 90 387ms 14 Oct 2023 889th Shanethegamer 🇺🇸 681 126 24ms 8 Jul 2021 890th jameslindesay 679 74 11ms 24 Feb 2021 890th PkmnQ 679 74 37ms 5 May 2024 890th HumanoidCPU 679 74 11ms 3 Jun 2024 890th RedzGoose 🇦🇺 679 74 11ms 14 Oct 2024 890th yokasuretsu 679 74 11ms 13 Jan 2025 895th I-Love-47 🇺🇦 679 106 62ms 10 Feb 2022 896th dokutan 678 59 3ms 18 Jul 2025 897th AdrienHache 🇫🇷 674 91 406ms 31 Dec 2023 898th janbehrens 🇩🇪 673 68 1,239ms 9 Apr 2021 899th msbranicky 672 80 4ms 11 Oct 2023 900th 5quiwyrm 670 54 293ms 5 Dec 2024 901st tatzyr 🇯🇵 670 63 39ms 29 Dec 2024 902nd Trunksistor 🇫🇷 670 75 11ms 25 May 2022 902nd celiendonze 🇨🇭 670 75 12ms 16 Jun 2023 902nd qwjhvbxi 670 75 11ms 9 Feb 2024 902nd wenbang24 670 75 14ms 6 Apr 2024 906th SirBogman 🇺🇸 667 108 61ms 3 Jan 2022 907th DialFrost 🇸🇬 666 56 83ms 22 Jul 2024 908th CaedenHarper 🇨🇦 666 70 11ms 31 Jan 2025 909th Natanaelel 🇸🇪 663 56 4ms 20 Jan 2024 910th DialFrost 🇸🇬 663 75 163ms 3 Jun 2025 911th dokutan 662 69 1,041ms 30 Aug 2025 912th 77Tigers 662 114 149ms 9 Apr 2024 913th Waffle3z 661 76 14ms 20 Jan 2021 913th hellwue 661 76 11ms 16 Nov 2023 913th dokutan 661 76 18ms 24 Mar 2025 916th HumanoidCPU 658 73 417ms 3 Jun 2024 917th uttumuttu 🇫🇮 657 71 9ms 8 Jan 2022 917th olleicua 🇺🇸 657 71 9ms 20 Feb 2024 919th emgordon154 655 70 142ms 6 Sep 2024 920th msbranicky 654 134 294ms 3 Oct 2023 921st dokutan 653 94 392ms 18 Jul 2025 922nd albanian-laundromat 653 98 39ms 28 Nov 2025 923rd olivermrose 🇺🇸 652 57 3ms 24 Aug 2021 924th f-tucker 652 77 11ms 2 Feb 2024 924th undefinedRyan 652 77 14ms 19 Apr 2025 924th Emutis 🇱🇹 652 77 12ms 12 Sep 2025 927th boxjelly 649 65 41ms 11 Feb 2021 927th msbranicky 649 65 38ms 12 Sep 2023 929th janbehrens 🇩🇪 649 135 282ms 13 Jun 2021 930th jwhear 🇺🇸 649 171 1,847ms 1 Oct 2024 931st MeWhenI 🇻🇦 646 71 175ms 3 Aug 2024 932nd AkashTandon167 644 78 11ms 25 May 2021 932nd jhpaques 🇫🇷 644 78 20ms 30 Nov 2022 934th johnnythedoggie 644 106 121ms 3 Mar 2021 934th snoozingnewt 🇨🇦 644 106 99ms 21 Nov 2025 936th rboath 643 58 83ms 8 Jan 2025 937th SirBogman 🇺🇸 643 84 2ms 14 Dec 2021 938th MateuszPietrzak 🇵🇱 643 112 55ms 16 Jan 2024 939th annaproxy 642 93 96ms 24 Dec 2022 940th NickTheEASDude 🇺🇸 642 95 1ms 1 Jul 2024 941st Shanethegamer 🇺🇸 641 97 9ms 22 Dec 2023 942nd CaedenHarper 🇨🇦 641 107 492ms 6 Oct 2025 943rd nephila-nacrea 🇬🇧 640 58 3ms 3 Feb 2021 944th KatieLG 🇬🇧 640 77 235ms 2 Oct 2022 945th alomiF 640 102 124ms 4 Nov 2024 946th Maznek 639 73 10ms 30 Jun 2023 947th Bubbler-4 639 97 72ms 13 Sep 2023 948th MeWhenI 🇻🇦 637 82 10ms 21 Jul 2023 949th ashtraypettingzoo 🇺🇸 636 36 32ms 23 Feb 2023 950th emgordon154 636 44 50ms 19 Feb 2026 951st twocatsinatrenchcoat 636 79 9ms 29 Mar 2022 951st SniperSmiley 🇺🇸 636 79 41ms 23 Jun 2022 951st Glinte 636 79 17ms 14 Dec 2023 951st Bmrl7 636 79 13ms 19 Mar 2024 951st acotis 636 79 12ms 21 days ago 956th Shanethegamer 🇺🇸 635 57 258ms 27 Jul 2023 957th sreyfe 635 119 156ms 9 Jun 2024 958th edsrzf 🇳🇿 635 138 294ms 21 Dec 2024 959th emgordon154 634 98 10ms 10 Dec 2024 960th MeWhenI 🇻🇦 633 90 2,844ms 24 Oct 2024 First Prev 881–960 of 1,943 Next Last