The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 4 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 393rd ndren 866 58 31ms 4 Aug 2023 393rd FlorianCassayre 🇫🇷 866 58 19ms 13 Sep 2023 393rd Kacarott 🇦🇺 866 58 28ms 13 Oct 2023 393rd m42km 866 58 28ms 25 Nov 2023 393rd NickTheEASDude 🇺🇸 866 58 27ms 1 Jul 2024 393rd namelessiw 866 58 30ms 27 Jul 2024 393rd edsrzf 🇳🇿 866 58 19ms 22 Nov 2024 393rd croc54 866 58 30ms 9 Jan 2025 393rd andrewjc2000 866 58 29ms 11 Mar 2025 393rd Mukundan314 866 58 32ms 27 Apr 2025 393rd fkantelberg 866 58 20ms 12 Jul 2025 393rd wuduculfre 866 58 29ms 22 Jul 2025 393rd HETHAT 🇩🇿 866 58 30ms 24 Sep 2025 393rd CornerMercury 🇬🇧 866 58 29ms 24 Nov 2025 393rd snoozingnewt 🇨🇦 866 58 18ms 1 Dec 2025 416th lukegustafson 🇺🇸 865 53 153ms 17 Jun 2025 417th stefangimmillaro 865 79 105ms 21 Jun 2023 418th janbehrens 🇩🇪 864 43 3ms 18 Jan 2021 419th Shanethegamer 🇺🇸 864 53 1,258ms 23 May 2021 419th MeWhenI 🇻🇦 864 53 1,291ms 16 Mar 2022 421st GrayJoKing 🇦🇺 864 90 100ms 9 Jun 2022 422nd DaCuteRaccoon 863 54 9ms 9 Dec 2022 423rd blaztoma 🇱🇹 862 46 6ms 16 days ago 424th edsrzf 🇳🇿 862 53 1,416ms 31 Aug 2025 424th DialFrost 🇸🇬 862 53 940ms 1 Sep 2025 424th xsot 🇸🇬 862 53 1,028ms 21 Dec 2025 427th bitsandbeyond 🇳🇱 861 42 237ms 27 Oct 2025 428th primo-ppcg 🇹🇭 861 49 47ms 18 Jan 2022 429th sisyphus-ppcg 🇦🇺 861 56 2ms 12 Jul 2022 430th error256 861 72 62ms 11 Dec 2025 431st DialFrost 🇸🇬 861 76 3ms 14 Sep 2024 432nd FortuiteMan 🇫🇷 860 84 12ms 16 Jan 2026 433rd frosster 🇨🇦 859 71 2ms 27 Jan 2026 434th GrayJoKing 🇦🇺 859 96 32ms 18 Jan 2023 434th lynn 859 96 39ms 6 Aug 2023 436th DialFrost 🇸🇬 858 56 414ms 15 Jan 2024 436th duckyluuk 🇳🇱 858 56 475ms 27 Mar 2024 438th Steffan153 🇫🇮 858 63 2ms 23 Mar 2023 438th stefangimmillaro 858 63 2ms 18 Sep 2023 438th xsot 🇸🇬 858 63 2ms 6 May 2025 438th KasperKivimaeki 🇫🇮 858 63 2ms 14 Aug 2025 442nd GrayJoKing 🇦🇺 857 79 8ms 20 days ago 442nd emgordon154 857 79 12ms 19 days ago 444th MeWhenI 🇻🇦 857 80 473ms 7 Nov 2025 445th jared-hughes 857 84 58ms 31 Jul 2022 445th inventshah 857 84 59ms 17 Nov 2022 447th Lydxn 🇨🇦 857 100 25ms 13 Oct 2023 448th primo-ppcg 🇹🇭 857 195 11ms 2 Aug 2023 449th Lydxn 🇨🇦 854 63 2ms 15 Jan 2024 449th JayXon 🇺🇸 854 63 2ms 29 Jan 2024 449th rucin93 🇵🇱 854 63 2ms 19 Nov 2025 452nd primo-ppcg 🇹🇭 854 78 124ms 27 Mar 2021 452nd Shanethegamer 🇺🇸 854 78 126ms 18 Mar 2023 452nd Ripick 854 78 123ms 2 Jun 2025 455th sean-niemann 🇺🇸 854 80 101ms 21 Sep 2023 455th Yewzir 🇧🇪 854 80 103ms 16 Nov 2023 457th snoozingnewt 🇨🇦 854 102 108ms 5 Dec 2025 458th nwellnhof 🇩🇪 852 43 155ms 21 Oct 2021 458th primo-ppcg 🇹🇭 852 43 154ms 22 Apr 2022 460th MeWhenI 🇻🇦 852 72 392ms 21 Nov 2021 461st MeWhenI 🇻🇦 852 84 40ms 29 Apr 2025 462nd marcin7Cd 851 59 10ms 16 Jan 2021 462nd rak1507 🇬🇧 851 59 10ms 20 Jan 2021 462nd AlephSquirrel 851 59 11ms 13 May 2021 462nd rschwa6308 🇺🇸 851 59 10ms 28 Jun 2021 462nd NewDefectus 🇮🇱 851 59 12ms 25 Oct 2021 462nd jacksonhenry3 851 59 13ms 21 Dec 2021 462nd NicoAdams 851 59 12ms 21 Dec 2021 462nd aksyristos 851 59 10ms 28 Feb 2023 462nd BREMAUCY 🇫🇷 851 59 11ms 27 Apr 2023 462nd 2011-Chan-Ethan 851 59 11ms 17 Jul 2023 462nd MarcMush 🇫🇷 851 59 10ms 12 Feb 2024 462nd albanian-laundromat 851 59 13ms 13 Apr 2025 462nd plcc0 851 59 11ms 13 Jan 2026 462nd CommandLeo 🇮🇹 851 59 11ms 18 Jan 2026 462nd pengu1n-master 851 59 11ms 10 Feb 2026 477th Shanethegamer 🇺🇸 851 67 2,626ms 27 Oct 2024 478th kg583 🇺🇸 851 86 9ms 1 Sep 2025 479th ovs-code 🇩🇪 851 138 1,466ms 17 Feb 2025 480th albanian-laundromat 850 77 9ms 22 Oct 2025 First Prev 401–480 of 1,939 Next Last