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 800th MeWhenI 🇻🇦 725 153 1,682ms 7 Nov 2025 802nd AlephSquirrel 722 34 51ms 30 Dec 2022 803rd scpchicken 🇵🇼 719 51 165ms 18 Jan 2023 804th Yewzir 🇧🇪 719 91 2ms 28 Mar 2024 805th osmith93 718 70 25ms 14 Jun 2021 805th ridingqwerty 🇺🇸 718 70 12ms 23 Feb 2024 805th mbittner20 718 70 11ms 15 Jul 2024 805th luuumine 🇫🇷 718 70 11ms 20 Oct 2025 809th igmcdowell 717 65 13ms 23 Nov 2021 810th msbranicky 717 67 496ms 17 Jan 2024 811th MeWhenI 🇻🇦 717 75 8ms 9 Oct 2023 812th prplz 🇦🇺 717 91 118ms 25 Jan 2021 813th marshallward 🇺🇸 716 100 41ms 7 May 2025 814th NewDefectus 🇮🇱 715 32 34ms 20 Dec 2021 815th NewDefectus 🇮🇱 714 21 2ms 14 Jan 2022 816th prplz 🇦🇺 714 52 3ms 5 Feb 2021 817th MarcMush 🇫🇷 714 69 304ms 12 Feb 2024 818th Herbert00709 🇵🇱 713 101 60ms 19 Nov 2024 819th emgordon154 712 80 2,629ms 9 Aug 2025 820th targrik 712 123 305ms 10 Jul 2025 821st NewDefectus 🇮🇱 711 76 2ms 25 Oct 2021 821st JohandeRuiter 🇳🇱 711 76 2ms 3 Dec 2023 823rd MeWhenI 🇻🇦 711 90 1,365ms 14 Jun 2023 824th chordowl 710 92 116ms 17 Mar 2021 825th marcin7Cd 710 103 21ms 12 Feb 2021 826th Feniske 🇫🇷 709 51 272ms 21 Nov 2023 827th aadenboy 🇺🇸 709 86 2ms 16 Dec 2025 828th SnowballSH 708 71 11ms 12 Feb 2021 828th Andre3582 708 71 11ms 18 Mar 2021 828th PhysicDev 🇫🇷 708 71 10ms 20 May 2021 828th Alban-Boissard 708 71 12ms 10 Jun 2025 832nd omurakazuaki 🇯🇵 706 66 10ms 18 Feb 2021 832nd BambooleanLogic 🇸🇪 706 66 12ms 22 Aug 2022 832nd coreynash 706 66 9ms 21 Oct 2023 832nd two-bad 🇬🇧 706 66 12ms 24 Nov 2023 832nd dylanarmstrong 706 66 10ms 15 Jan 2024 832nd madeforlosers 706 66 10ms 5 Nov 2025 838th Stockoh 🇫🇷 706 68 427ms 24 Jun 2024 839th typeswitch-dev 🇵🇹 705 74 8ms 7 Aug 2023 840th msbranicky 704 65 1,289ms 12 Sep 2023 841st Shanethegamer 🇺🇸 704 91 39ms 16 Jun 2022 842nd SnowballSH 703 60 36ms 12 Feb 2021 842nd aksyristos 703 60 37ms 28 Feb 2023 842nd Lv0Sys 🇵🇱 703 60 40ms 4 Dec 2025 845th primo-ppcg 🇹🇭 702 47 1,032ms 5 Feb 2022 846th MeWhenI 🇻🇦 702 238 12ms 29 Aug 2023 847th MeWhenI 🇻🇦 701 35 51ms 26 Jul 2022 847th jared-hughes 701 35 48ms 31 Jul 2022 847th Natanaelel 🇸🇪 701 35 50ms 18 Aug 2022 850th KasperKivimaeki 🇫🇮 701 125 288ms 3 Oct 2025 851st JayXon 🇺🇸 700 40 46ms 2 Jun 2021 852nd UnderKoen 🇳🇱 700 134 13ms 20 Jan 2025 853rd jared-hughes 699 44 6ms 31 Jul 2022 854th Shanethegamer 🇺🇸 699 77 13ms 9 Oct 2023 855th JGDoerrer 699 103 445ms 5 Jan 2022 855th tailorspy 699 103 59ms 29 Oct 2023 857th LeeCamp 698 72 10ms 16 Feb 2022 857th LukasFolwarczny 🇨🇿 698 72 10ms 16 Sep 2022 857th CutSandstone 698 72 38ms 8 Jul 2024 860th jared-hughes 698 159 1,670ms 16 Sep 2025 861st targrik 696 57 5ms 26 Aug 2025 862nd neihousaigaai 696 67 9ms 10 Apr 2021 863rd boxjelly 694 94 114ms 21 Jan 2021 863rd YAJUE114514 694 94 133ms 24 Jul 2025 865th dokutan 693 99 372ms 24 Sep 2025 866th Espiobest 692 61 34ms 13 Feb 2021 866th DaCuteRaccoon 692 61 42ms 9 Dec 2022 868th MeWhenI 🇻🇦 691 106 345ms 26 Aug 2023 869th Shanethegamer 🇺🇸 690 106 17ms 4 Oct 2024 870th msbranicky 689 95 5ms 11 Aug 2023 871st GolfingSuccess 🇬🇷 688 69 33ms 17 Aug 2024 872nd richard-oelze 🇩🇪 688 73 30ms 4 Apr 2021 872nd mauro-1 🇮🇹 688 73 9ms 18 Aug 2021 872nd gchenfc 688 73 9ms 24 Jan 2022 872nd hiichbindermax 688 73 11ms 26 Feb 2022 872nd Omega65536 🇩🇪 688 73 11ms 24 Nov 2022 872nd sandorstormen 688 73 11ms 18 Feb 2023 872nd Mr-McChicken 688 73 10ms 15 Oct 2023 872nd Masttest 688 73 10ms 21 Feb 2024 880th Andriamanitra 🇫🇮 687 95 148ms 20 Jul 2023 First Prev 801–880 of 1,943 Next Last