The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 3 days. Why not try and solve them ahead of time?
Leap Years 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 801st villfa 884 50 4ms 27 May 2019 801st UpwardProcess 884 50 5ms 30 Jul 2019 801st ondras 884 50 5ms 3 May 2020 801st cywong-amino 🇭🇰 884 50 4ms 20 May 2020 801st Attero 🇸🇪 884 50 5ms 31 Aug 2020 801st sisyphus-ppcg 🇦🇺 884 50 4ms 5 Nov 2020 801st toubsen 🇩🇪 884 50 5ms 26 Dec 2020 808th primo-ppcg 🇹🇭 884 87 270ms 2 May 2020 809th ETHproductions 🇺🇸 883 37 337ms 22 Dec 2018 809th dokutan 883 37 337ms 18 Mar 2025 811th prplz 🇦🇺 883 48 16ms 19 Sep 2019 811th TFeld00 🇩🇰 883 48 10ms 3 Mar 2020 811th GolfingSuccess 🇬🇷 883 48 15ms 17 Nov 2020 811th urojony 🇵🇱 883 48 21ms 26 Dec 2020 811th btjones0 883 48 17ms 30 Dec 2020 811th Indivicivet 883 48 17ms 22 Mar 2021 811th NewDefectus 🇮🇱 883 48 16ms 27 May 2021 811th Bubbler-4 883 48 9ms 16 Nov 2021 811th KatieLG 🇬🇧 883 48 16ms 2 Jun 2022 811th k3w1k0d3r 883 48 10ms 29 Jun 2022 811th FlorianCassayre 🇫🇷 883 48 16ms 6 Mar 2023 811th quimey 883 48 15ms 15 Jun 2023 811th Andriamanitra 🇫🇮 883 48 17ms 10 Jul 2023 811th stefangimmillaro 883 48 9ms 18 Jul 2023 811th Alex-x90 🇺🇸 883 48 10ms 27 Jul 2023 811th sultan 883 48 10ms 16 Feb 2024 811th driri85 883 48 10ms 16 Feb 2024 811th wen1now 883 48 10ms 1 Mar 2024 811th cpchrispye 883 48 16ms 20 Apr 2024 811th 5cw 🇺🇸 883 48 17ms 6 May 2024 811th egasyelir 883 48 17ms 15 Jul 2024 811th bzijlema 🇳🇱 883 48 17ms 11 Sep 2024 811th moustave 883 48 16ms 9 Jan 2025 811th rollershutter 883 48 16ms 21 Jan 2025 811th Yax42 🇫🇷 883 48 9ms 17 Jun 2025 811th luuumine 🇫🇷 883 48 10ms 29 Oct 2025 811th solisolu 883 48 17ms 1 Jan 2026 838th yanjs 883 53 119ms 3 Jul 2025 839th Steffan153 🇫🇮 882 61 15ms 22 Aug 2024 840th lynn 881 32 3ms 26 Mar 2021 840th perlebach 🇨🇿 881 32 3ms 13 Aug 2021 840th Steffan153 🇫🇮 881 32 3ms 24 Feb 2023 840th sean-niemann 🇺🇸 881 32 3ms 13 Mar 2025 844th emplv 🇱🇻 881 55 113ms 26 Oct 2022 844th voytxt 🇨🇿 881 55 122ms 1 Jan 2023 844th stefangimmillaro 881 55 115ms 20 Jun 2023 844th mulmul9 🇭🇺 881 55 115ms 8 Sep 2023 848th GrayJoKing 🇦🇺 881 57 4ms 16 Jul 2023 849th initram 881 62 343ms 21 Nov 2021 849th janbehrens 🇩🇪 881 62 367ms 21 Nov 2021 849th jmhowl 881 62 370ms 21 Nov 2021 849th ScottHamper 881 62 360ms 21 Nov 2021 849th Irratix 🇳🇱 881 62 362ms 13 Dec 2021 849th simon-biber 881 62 346ms 7 Feb 2022 849th annaproxy 881 62 355ms 15 Mar 2022 849th voytxt 🇨🇿 881 62 377ms 7 Apr 2022 849th logicolor 881 62 367ms 27 Apr 2022 849th Gaddy 🇫🇷 881 62 370ms 2 May 2022 849th Romain-1 🇫🇷 881 62 346ms 3 May 2022 849th AdrienHache 🇫🇷 881 62 412ms 6 Jun 2023 849th jwonagel 881 62 369ms 25 Sep 2023 849th Babafaba 881 62 366ms 15 Oct 2025 863rd Wanderkind 🇰🇷 881 71 449ms 9 Jan 2023 864th DialFrost 🇸🇬 881 109 1,443ms 7 Mar 2025 864th MeWhenI 🇻🇦 881 109 1,431ms 28 Mar 2025 864th Steffan153 🇫🇮 881 109 1,448ms 4 days ago 867th JayXon 🇺🇸 881 121 1,653ms 15 Sep 2025 868th Steffan153 🇫🇮 880 72 3ms 5 days ago 869th voytxt 🇨🇿 879 35 1,272ms 16 May 2022 869th lynn 879 35 1,257ms 1 Jun 2022 869th emgordon154 879 35 1,230ms 5 Oct 2025 869th edsrzf 🇳🇿 879 35 1,266ms 21 Dec 2025 873rd MeWhenI 🇻🇦 878 46 5ms 31 Dec 2024 874th frosster 🇨🇦 878 48 2ms 11 Feb 2026 875th sean-niemann 🇺🇸 877 47 144ms 20 Mar 2022 875th MeWhenI 🇻🇦 877 47 140ms 10 Oct 2022 875th DialFrost 🇸🇬 877 47 149ms 8 Nov 2023 875th dokutan 877 47 139ms 25 Sep 2024 879th inventshah 877 50 2ms 9 Sep 2022 879th janbehrens 🇩🇪 877 50 2ms 14 Sep 2022 First Prev 801–880 of 4,856 Next Last