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 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 394th luuumine 🇫🇷 924 77 69ms 16 Nov 2025 402nd xsot 🇸🇬 923 48 5ms 13 Apr 2024 402nd sean-niemann 🇺🇸 923 48 4ms 16 Jul 2024 404th btnlq 922 35 3ms 17 Aug 2024 404th ovs-code 🇩🇪 922 35 3ms 20 Aug 2024 406th xsot 🇸🇬 922 46 16ms 25 Nov 2019 406th primo-ppcg 🇹🇭 922 46 10ms 27 Nov 2019 406th dlenski 922 46 17ms 11 Mar 2020 406th marcin7Cd 922 46 10ms 15 Mar 2020 406th jmhowl 922 46 17ms 20 Mar 2020 406th lenabradley 922 46 17ms 20 Mar 2020 406th loserface69 922 46 16ms 19 May 2020 406th LlamaLad7 🇬🇧 922 46 17ms 19 May 2020 406th hallvabo 🇳🇴 922 46 16ms 7 Nov 2020 406th nwellnhof 🇩🇪 922 46 16ms 1 Jan 2021 406th HETHAT 🇩🇿 922 46 16ms 2 Mar 2021 406th lynn 922 46 17ms 26 Mar 2021 406th GrayJoKing 🇦🇺 922 46 9ms 3 Apr 2021 406th kops-cg 922 46 10ms 6 Apr 2021 406th m-tkach 🇺🇦 922 46 16ms 5 Jun 2021 406th orthoplex 🇨🇽 922 46 9ms 13 Jan 2022 406th jared-hughes 922 46 12ms 10 Mar 2022 406th bricknellj 922 46 17ms 2 Jun 2022 406th MeWhenI 🇻🇦 922 46 10ms 10 Oct 2022 406th ovs-code 🇩🇪 922 46 17ms 27 Nov 2022 406th AlephSquirrel 922 46 10ms 26 Dec 2022 406th neel11235813 922 46 10ms 3 Jan 2023 406th b10011 🇫🇮 922 46 9ms 3 Jan 2023 406th DialFrost 🇸🇬 922 46 10ms 20 Oct 2023 406th ndren 922 46 16ms 19 Nov 2023 406th davecame 922 46 17ms 11 Dec 2023 406th rucin93 🇵🇱 922 46 9ms 19 Jan 2024 406th Grrisly 922 46 17ms 27 Mar 2024 406th b-illy 🇬🇧 922 46 16ms 18 Jul 2024 406th zach333 922 46 10ms 20 Jul 2024 406th zacjl 922 46 18ms 20 Sep 2024 406th FlyingPenguin223 922 46 10ms 17 Dec 2024 406th Mukundan314 922 46 16ms 25 Apr 2025 406th fuzzylojik-golf 🇺🇸 922 46 16ms 28 Jun 2025 406th CaedenHarper 🇨🇦 922 46 9ms 24 Jul 2025 406th qpwoeirut 922 46 10ms 24 Aug 2025 406th Babafaba 922 46 16ms 13 Oct 2025 406th 09cf 922 46 16ms 25 Nov 2025 406th edsrzf 🇳🇿 922 46 16ms 14 Dec 2025 406th blaztoma 🇱🇹 922 46 16ms 16 Jan 2026 446th Lydxn 🇨🇦 922 68 453ms 27 Feb 2022 446th sean-niemann 🇺🇸 922 68 434ms 28 Feb 2022 446th JayXon 🇺🇸 922 68 437ms 28 Feb 2022 446th GrayJoKing 🇦🇺 922 68 458ms 28 Feb 2022 446th MeWhenI 🇻🇦 922 68 438ms 10 Oct 2022 446th ovs-code 🇩🇪 922 68 439ms 31 Dec 2022 446th Steffan153 🇫🇮 922 68 435ms 1 Jan 2023 446th DialFrost 🇸🇬 922 68 433ms 8 Nov 2023 446th dokutan 922 68 444ms 27 Sep 2025 446th fuzzylojik-golf 🇺🇸 922 68 428ms 110 mins ago 456th GrayJoKing 🇦🇺 921 44 5ms 31 Jan 2025 457th primo-ppcg 🇹🇭 921 45 1ms 7 Nov 2022 457th xsot 🇸🇬 921 45 3ms 18 Mar 2024 459th Steffan153 🇫🇮 919 35 36ms 4 days ago 460th primo-ppcg 🇹🇭 919 45 146ms 6 Sep 2023 460th Steffan153 🇫🇮 919 45 134ms 4 days ago 462nd olivermrose 🇺🇸 919 51 118ms 23 Aug 2021 463rd lynn 919 60 25ms 11 Jul 2023 463rd Lydxn 🇨🇦 919 60 25ms 11 Jul 2023 463rd Steffan153 🇫🇮 919 60 27ms 4 days ago 466th Lydxn 🇨🇦 918 41 1ms 8 Oct 2023 466th MeWhenI 🇻🇦 918 41 1ms 18 Aug 2024 468th Attero 🇸🇪 918 46 1ms 9 May 2020 468th Waffle3z 918 46 1ms 11 Jul 2021 468th GrayJoKing 🇦🇺 918 46 2ms 9 Feb 2022 468th jared-hughes 918 46 1ms 10 Mar 2022 468th MeWhenI 🇻🇦 918 46 1ms 31 Dec 2022 468th b10011 🇫🇮 918 46 2ms 5 Jan 2023 468th sean-niemann 🇺🇸 918 46 1ms 12 Jan 2023 468th DialFrost 🇸🇬 918 46 2ms 8 Nov 2023 468th dokutan 918 46 1ms 25 Sep 2024 468th FlyingPenguin223 918 46 1ms 17 Dec 2024 468th edsrzf 🇳🇿 918 46 2ms 14 Dec 2025 468th fuzzylojik-golf 🇺🇸 918 46 2ms 66 mins ago 480th DialFrost 🇸🇬 917 28 324ms 14 Dec 2025 First Prev 401–480 of 4,877 Next Last