The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 7 days. Why not try and solve them ahead of time?
Day of Week 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 791st Rubiksmath 771 85 14ms 5 Oct 2023 791st StefanHabel 🇨🇦 771 85 14ms 12 Oct 2023 791st lynn 771 85 13ms 14 Oct 2023 791st jakobkordez 🇸🇮 771 85 15ms 16 Nov 2023 791st bizy-coder 771 85 17ms 24 Nov 2023 791st bzijlema 🇳🇱 771 85 15ms 28 Nov 2023 791st quimey 771 85 14ms 30 Nov 2023 791st AlephSquirrel 771 85 14ms 21 Jan 2024 791st mathisfun271 771 85 37ms 2 Feb 2024 791st fourth-bit 771 85 15ms 14 Mar 2024 791st Bulmenisaurus 771 85 13ms 1 Jul 2024 791st jipsong 🇩🇪 771 85 14ms 25 Jul 2024 791st davecame 771 85 14ms 18 Sep 2024 791st bricknellj 771 85 13ms 19 Jan 2025 791st 4atj 771 85 14ms 30 Jun 2025 791st dirckvdende 771 85 13ms 7 Jul 2025 791st KapelMeister 771 85 17ms 30 Aug 2025 791st ahmetdemirag 🇨🇾 771 85 35ms 1 Oct 2025 791st CommandLeo 🇮🇹 771 85 16ms 23 Nov 2025 791st HPWiz 🇳🇿 771 85 14ms 26 Nov 2025 791st Languag3 771 85 17ms 5 Dec 2025 791st blaztoma 🇱🇹 771 85 14ms 7 Dec 2025 791st Lv0Sys 🇵🇱 771 85 15ms 8 Dec 2025 824th lynn 771 206 31ms 11 Jul 2023 825th MeWhenI 🇻🇦 770 49 37ms 25 Dec 2023 825th GrayJoKing 🇦🇺 770 49 38ms 26 Dec 2023 825th DialFrost 🇸🇬 770 49 38ms 20 Dec 2024 828th msbranicky 770 115 59ms 3 Jan 2024 829th stefangimmillaro 769 240 249ms 16 Nov 2023 830th Yewzir 🇧🇪 768 176 5ms 25 Mar 2024 831st KasperKivimaeki 🇫🇮 767 134 3,039ms 26 Oct 2025 832nd funnyboy-roks 766 88 53ms 15 Jun 2024 833rd MeWhenI 🇻🇦 765 57 5ms 28 May 2023 834th MeWhenI 🇻🇦 765 95 227ms 17 Apr 2023 834th Yewzir 🇧🇪 765 95 219ms 12 May 2023 836th 4hg 🇺🇸 764 58 1,462ms 17 Apr 2023 837th Daveoc64 764 77 383ms 15 Jun 2023 838th rucin93 🇵🇱 764 78 210ms 31 Oct 2024 839th jmerle 🇳🇱 764 163 811ms 15 Jun 2023 840th DialFrost 🇸🇬 764 177 5ms 30 Jan 2026 841st jfrmilner 🇬🇧 762 21 261ms 12 Aug 2023 841st NicolasBn 🇫🇷 762 21 248ms 21 Sep 2023 841st kewegmey 762 21 244ms 4 Jan 2024 844th zwxzwxzwx21 762 86 16ms 30 Jan 2024 845th firewoods1978 762 112 2ms 12 Oct 2024 846th sisyphus-ppcg 🇦🇺 762 126 12ms 26 May 2023 847th eli-siegel 762 140 273ms 23 Jun 2023 847th mpldr 🇩🇪 762 140 293ms 23 Oct 2023 849th inventshah 761 53 2ms 16 Apr 2023 850th emgordon154 760 331 1,677ms 16 Jan 2026 851st SirBogman 🇺🇸 756 102 3ms 23 Apr 2023 852nd dokutan 755 64 1,023ms 18 Aug 2025 853rd Steffan153 🇫🇮 755 131 7ms 20 Aug 2023 853rd primo-ppcg 🇹🇭 755 131 7ms 27 Jan 2025 853rd sean-niemann 🇺🇸 755 131 7ms 27 Sep 2025 856th ovs-code 🇩🇪 754 79 209ms 17 Apr 2025 857th ovs-code 🇩🇪 753 81 403ms 16 Jan 2024 857th bizy-coder 753 81 421ms 20 Jan 2024 857th SirBogman 🇺🇸 753 81 391ms 20 Jan 2024 857th m-tkach 🇺🇦 753 81 460ms 21 Jan 2024 857th AlephSquirrel 753 81 402ms 22 Jan 2024 857th lynn 753 81 444ms 17 Feb 2024 863rd NewDefectus 🇮🇱 753 87 14ms 19 Aug 2023 863rd Emutis 🇱🇹 753 87 15ms 7 Dec 2025 865th emgordon154 753 245 254ms 19 Apr 2025 866th eclyptox 752 58 5ms 13 Oct 2024 866th me42th 752 58 5ms 16 Jun 2025 868th Shanethegamer 🇺🇸 750 132 7ms 20 Aug 2023 869th DanielVenable 749 90 55ms 7 Aug 2025 869th elisherer 🇮🇱 749 90 48ms 3 Nov 2025 871st GolfingSuccess 🇬🇷 747 52 5ms 12 Aug 2024 872nd 0dyse 746 47 79ms 6 May 2025 873rd Natanaelel 🇸🇪 746 54 2ms 25 Apr 2023 873rd GolfingSuccess 🇬🇷 746 54 2ms 16 Oct 2024 875th Yewzir 🇧🇪 746 337 1,732ms 28 Apr 2024 876th Yewzir 🇧🇪 745 80 264ms 3 Aug 2024 876th voytxt 🇨🇿 745 80 220ms 3 Aug 2024 876th GrayJoKing 🇦🇺 745 80 210ms 12 Aug 2024 879th Daveoc64 745 91 1,274ms 15 Jun 2023 880th MeWhenI 🇻🇦 745 112 4ms 26 May 2023 First Prev 801–880 of 1,505 Next Last