The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 6 days. Why not try and solve them ahead of time?
Rule 110 in all languages in chars. 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 Chars Time Submitted 161st ovs-code 🇩🇪 891 89 100ms 19 Dec 2025 162nd m-tkach 🇺🇦 891 177 985ms 15 Jan 2025 163rd tomtheisen 🇺🇸 890 79 12ms 2 Oct 2020 163rd dmrichwa 🇺🇸 890 79 12ms 18 Dec 2022 165th inventshah 890 104 281ms 28 Oct 2023 166th primo-ppcg 🇹🇭 889 96 100ms 10 Nov 2023 167th MeWhenI 🇻🇦 889 119 110ms 14 Mar 2023 168th JayXon 🇺🇸 888 89 421ms 28 Jun 2024 169th sean-niemann 🇺🇸 887 100 633ms 14 Apr 2025 170th primo-ppcg 🇹🇭 887 146 26ms 25 Jun 2022 171st JayXon 🇺🇸 887 155 1,674ms 15 Sep 2025 172nd sean-niemann 🇺🇸 886 81 3ms 3 Feb 2024 173rd Alex-x90 🇺🇸 886 87 7ms 11 Feb 2023 173rd ovs-code 🇩🇪 886 87 6ms 6 May 2025 175th typeswitch-dev 🇵🇹 885 120 4ms 7 Aug 2023 175th GrayJoKing 🇦🇺 885 120 18ms 8 Aug 2023 177th primo-ppcg 🇹🇭 883 117 42ms 2 May 2019 178th ngn 🇧🇬 881 42 3ms 13 Jan 2022 179th sean-niemann 🇺🇸 881 100 9ms 28 Dec 2023 180th Alex-x90 🇺🇸 881 108 62ms 23 Feb 2023 181st primo-ppcg 🇹🇭 881 122 44ms 21 Jun 2022 182nd Kacarott 🇦🇺 880 97 62ms 9 Dec 2025 183rd btnlq 879 89 26ms 12 Dec 2021 184th DialFrost 🇸🇬 878 66 10ms 24 Nov 2023 185th kg583 🇺🇸 877 108 43ms 24 Oct 2025 186th MeWhenI 🇻🇦 875 136 72ms 1 Aug 2023 187th edsrzf 🇳🇿 874 128 147ms 15 Dec 2025 188th btnlq 870 72 354ms 23 Feb 2021 189th zacjl 870 119 44ms 13 Feb 2025 190th primo-ppcg 🇹🇭 870 158 1,815ms 9 Jun 2024 191st namelessiw 869 91 459ms 28 Jun 2024 191st stefangimmillaro 869 91 407ms 15 Jan 2025 193rd ovs-code 🇩🇪 869 191 1,433ms 2 Feb 2025 194th emgordon154 866 66 1,515ms 3 Aug 2025 195th xsot 🇸🇬 866 83 15ms 24 May 2025 196th sean-niemann 🇺🇸 866 124 46ms 16 Jan 2026 197th Irratix 🇳🇱 865 110 69ms 15 Dec 2022 198th xnor-gate 864 91 149ms 26 Dec 2021 199th MeWhenI 🇻🇦 864 93 20ms 1 Jan 2025 200th SirBogman 🇺🇸 861 46 32ms 28 Nov 2022 200th stackofbears 861 46 36ms 23 Feb 2024 202nd bstrat 860 43 4ms 18 Jun 2024 203rd Natanaelel 🇸🇪 860 63 39ms 29 Jul 2023 204th jared-hughes 859 244 19ms 23 Dec 2023 205th primo-ppcg 🇹🇭 858 72 1,049ms 8 Feb 2022 206th nwellnhof 🇩🇪 857 90 6ms 12 Feb 2020 206th prplz 🇦🇺 857 90 6ms 25 Sep 2021 208th Attero 🇸🇪 856 84 16ms 20 Sep 2023 209th ovs-code 🇩🇪 855 92 135ms 11 Nov 2023 210th primo-ppcg 🇹🇭 853 117 164ms 31 May 2021 211th TFeld00 🇩🇰 852 68 210ms 4 Nov 2020 211th 4atj 852 68 10ms 22 Apr 2025 211th davecame 852 68 10ms 13 Nov 2025 211th snoozingnewt 🇨🇦 852 68 13ms 13 days ago 215th GolfingSuccess 🇬🇷 852 191 103ms 3 days ago 216th JayXon 🇺🇸 849 149 292ms 18 Sep 2024 217th primo-ppcg 🇹🇭 848 258 54ms 2 Aug 2023 218th helbling 🇨🇭 847 83 13ms 20 Feb 2024 219th SirBogman 🇺🇸 846 64 39ms 28 Nov 2022 219th MeWhenI 🇻🇦 846 64 40ms 25 Jul 2023 219th emgordon154 846 64 34ms 3 Aug 2025 222nd emgordon154 841 45 63ms 11 Nov 2025 223rd xnor-gate 839 69 10ms 25 Mar 2021 223rd lynn 839 69 11ms 8 Dec 2021 223rd nwellnhof 🇩🇪 839 69 10ms 27 Jul 2023 223rd stefangimmillaro 839 69 10ms 19 Sep 2024 223rd cefqrn 839 69 11ms 3 Jul 2025 223rd sunleonid 839 69 10ms 5 Dec 2025 223rd sisyphus-ppcg 🇦🇺 839 69 10ms 15 Dec 2025 223rd bizy-coder 839 69 10ms 15 Dec 2025 231st kumavale 838 115 136ms 14 Nov 2025 232nd Attero 🇸🇪 837 84 11ms 21 Oct 2020 233rd duckyluuk 🇳🇱 837 96 23ms 25 Jun 2025 234th sean-niemann 🇺🇸 836 86 10ms 28 Dec 2023 235th Steffan153 🇫🇮 836 94 87ms 12 Feb 2026 236th inventshah 836 107 2,741ms 20 Nov 2024 237th nwellnhof 🇩🇪 834 114 65ms 24 Jul 2023 238th primo-ppcg 🇹🇭 833 127 113ms 23 Jan 2020 239th m-tkach 🇺🇦 831 67 421ms 23 Jul 2024 240th MeWhenI 🇻🇦 831 114 8ms 9 May 2024 First Prev 161–240 of 1,658 Next Last