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 373rd b-illy 🇬🇧 921 46 16ms 18 Jul 2024 373rd zach333 921 46 10ms 20 Jul 2024 373rd zacjl 921 46 18ms 20 Sep 2024 373rd FlyingPenguin223 921 46 10ms 17 Dec 2024 373rd Mukundan314 921 46 16ms 25 Apr 2025 373rd fuzzylojik-golf 🇺🇸 921 46 16ms 28 Jun 2025 373rd CaedenHarper 🇨🇦 921 46 9ms 24 Jul 2025 373rd qpwoeirut 921 46 10ms 24 Aug 2025 373rd Babafaba 921 46 16ms 13 Oct 2025 373rd 09cf 921 46 16ms 25 Nov 2025 373rd edsrzf 🇳🇿 921 46 16ms 14 Dec 2025 373rd blaztoma 🇱🇹 921 46 16ms 16 Jan 2026 413th xsot 🇸🇬 921 48 5ms 13 Apr 2024 413th sean-niemann 🇺🇸 921 48 4ms 16 Jul 2024 415th Lydxn 🇨🇦 920 68 453ms 27 Feb 2022 415th sean-niemann 🇺🇸 920 68 434ms 28 Feb 2022 415th JayXon 🇺🇸 920 68 437ms 28 Feb 2022 415th GrayJoKing 🇦🇺 920 68 458ms 28 Feb 2022 415th MeWhenI 🇻🇦 920 68 438ms 10 Oct 2022 415th ovs-code 🇩🇪 920 68 439ms 31 Dec 2022 415th Steffan153 🇫🇮 920 68 435ms 1 Jan 2023 415th DialFrost 🇸🇬 920 68 433ms 8 Nov 2023 415th dokutan 920 68 444ms 27 Sep 2025 415th fuzzylojik-golf 🇺🇸 920 68 428ms 15 hours ago 425th primo-ppcg 🇹🇭 919 45 1ms 7 Nov 2022 425th xsot 🇸🇬 919 45 3ms 18 Mar 2024 427th btnlq 918 35 3ms 17 Aug 2024 427th ovs-code 🇩🇪 918 35 3ms 20 Aug 2024 429th nwellnhof 🇩🇪 918 57 1ms 11 Feb 2020 429th primo-ppcg 🇹🇭 918 57 1ms 22 Aug 2020 429th Irratix 🇳🇱 918 57 1ms 13 Jun 2022 429th madex 🇩🇪 918 57 2ms 12 Nov 2022 429th inventshah 918 57 2ms 26 Jan 2023 429th xsot 🇸🇬 918 57 2ms 16 Apr 2023 429th JohandeRuiter 🇳🇱 918 57 2ms 25 Oct 2023 429th dokutan 918 57 2ms 25 Sep 2024 429th FlyingPenguin223 918 57 1ms 10 Feb 2025 429th kdx2a 918 57 1ms 11 Feb 2025 429th Mukundan314 918 57 2ms 26 Apr 2025 429th fuzzylojik-golf 🇺🇸 918 57 1ms 28 Jun 2025 429th Yax42 🇫🇷 918 57 2ms 15 Oct 2025 429th 09cf 918 57 2ms 25 Nov 2025 443rd janlelis 917 35 37ms 7 Feb 2021 443rd Steffan153 🇫🇮 917 35 36ms 4 days ago 445th GrayJoKing 🇦🇺 917 44 5ms 31 Jan 2025 446th Attero 🇸🇪 917 46 1ms 9 May 2020 446th Waffle3z 917 46 1ms 11 Jul 2021 446th GrayJoKing 🇦🇺 917 46 2ms 9 Feb 2022 446th jared-hughes 917 46 1ms 10 Mar 2022 446th MeWhenI 🇻🇦 917 46 1ms 31 Dec 2022 446th b10011 🇫🇮 917 46 2ms 5 Jan 2023 446th sean-niemann 🇺🇸 917 46 1ms 12 Jan 2023 446th DialFrost 🇸🇬 917 46 2ms 8 Nov 2023 446th dokutan 917 46 1ms 25 Sep 2024 446th FlyingPenguin223 917 46 1ms 17 Dec 2024 446th edsrzf 🇳🇿 917 46 2ms 14 Dec 2025 446th fuzzylojik-golf 🇺🇸 917 46 2ms 15 hours ago 458th olivermrose 🇺🇸 917 51 118ms 23 Aug 2021 459th lynn 917 60 25ms 11 Jul 2023 459th Lydxn 🇨🇦 917 60 25ms 11 Jul 2023 459th Steffan153 🇫🇮 917 60 27ms 4 days ago 462nd primo-ppcg 🇹🇭 916 45 146ms 6 Sep 2023 462nd Steffan153 🇫🇮 916 45 134ms 4 days ago 464th Lydxn 🇨🇦 915 41 1ms 8 Oct 2023 464th MeWhenI 🇻🇦 915 41 1ms 18 Aug 2024 466th DialFrost 🇸🇬 914 28 324ms 14 Dec 2025 467th GrayJoKing 🇦🇺 914 53 129ms 18 Oct 2022 468th Lydxn 🇨🇦 914 55 4ms 16 Jul 2023 469th voytxt 🇨🇿 913 42 150ms 3 Aug 2024 469th pardouin 🇫🇷 913 42 136ms 5 Aug 2024 471st somebody1234 912 43 10ms 7 Dec 2018 471st dymowski 912 43 9ms 7 Jul 2019 471st KrausRaus 🇺🇸 912 43 9ms 22 Aug 2019 471st handisb 912 43 11ms 31 Aug 2019 471st dorinoltean 912 43 9ms 2 Oct 2019 471st oitio 912 43 10ms 12 Feb 2020 471st shuding 912 43 8ms 27 Apr 2020 471st taklam 912 43 10ms 20 May 2020 471st raphaelimahorn 912 43 10ms 4 Sep 2020 471st revlayle 🇺🇸 912 43 10ms 14 Sep 2020 First Prev 401–480 of 4,856 Next Last