The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 2 days. Why not try and solve them ahead of time?
Happy Numbers 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 880th ovs-code 🇩🇪 702 62 405ms 2 Mar 2024 880th KatieLG 🇬🇧 702 62 375ms 28 Oct 2024 883rd saito-ta 🇯🇵 702 75 6ms 22 Jun 2022 883rd inventshah 702 75 1ms 25 Jan 2023 883rd Yewzir 🇧🇪 702 75 1ms 22 Dec 2023 883rd KasperKivimaeki 🇫🇮 702 75 2ms 5 Jan 2025 887th jmerle 🇳🇱 702 100 6ms 4 Jul 2023 888th dbut2 🇦🇺 702 121 269ms 15 Jul 2025 889th MeWhenI 🇻🇦 700 69 2ms 10 Sep 2022 889th Yewzir 🇧🇪 700 69 2ms 22 Dec 2023 889th sean-niemann 🇺🇸 700 69 2ms 8 Oct 2024 889th albanian-laundromat 700 69 2ms 24 Jun 2025 893rd jared-hughes 700 94 494ms 24 Sep 2025 894th Bubbler-4 699 49 65ms 13 Sep 2023 894th ovs-code 🇩🇪 699 49 63ms 13 Sep 2023 896th JunkIce 699 90 128ms 23 Feb 2025 896th dokutan 699 90 125ms 23 Jul 2025 898th edsrzf 🇳🇿 697 70 6ms 19 days ago 899th snoozingnewt 🇨🇦 697 89 467ms 29 Nov 2025 900th Steffan153 🇫🇮 697 99 65ms 28 Jan 2023 900th ovs-code 🇩🇪 697 99 51ms 3 Jun 2024 900th roupiq 🇵🇱 697 99 56ms 8 Jun 2024 903rd jared-hughes 696 71 9ms 29 Oct 2021 903rd stefangimmillaro 696 71 10ms 27 Aug 2022 903rd SirFireball3521 696 71 10ms 28 Jan 2023 903rd Maznek 696 71 13ms 19 Jun 2023 903rd snoozingnewt 🇨🇦 696 71 12ms 29 Nov 2025 908th msbranicky 696 74 80ms 14 Aug 2023 909th dokutan 695 88 107ms 12 Dec 2025 910th MeWhenI 🇻🇦 695 133 1,642ms 7 Nov 2025 911th xorraxrax 693 68 9ms 19 Oct 2019 911th NewDefectus 🇮🇱 693 68 11ms 1 Nov 2020 911th ydevor 🇮🇱 693 68 10ms 26 Nov 2020 911th jacklynnepenick 693 68 50ms 17 Aug 2021 911th aposteriorist 🇨🇦 693 68 11ms 6 Feb 2022 911th PowerR0 693 68 9ms 25 Aug 2022 911th SB-945 693 68 17ms 31 Mar 2024 911th Troon 693 68 10ms 11 Feb 2025 919th sisyphus-ppcg 🇦🇺 692 43 2ms 3 Nov 2020 919th pandapawskat 692 43 1ms 20 Sep 2021 919th stefangimmillaro 692 43 2ms 23 Apr 2022 922nd o0lit3 🇺🇸 692 50 13ms 19 Apr 2021 922nd armin-k1 692 50 8ms 8 Sep 2021 924th btnlq 692 63 3ms 15 Jul 2023 925th Alex-x90 🇺🇸 692 76 1ms 3 Dec 2022 926th snoozingnewt 🇨🇦 692 95 431ms 29 Nov 2025 927th anter69 🇭🇺 691 55 1,259ms 10 Mar 2025 928th GrayJoKing 🇦🇺 691 61 124ms 13 Mar 2022 929th SirBogman 🇺🇸 691 63 406ms 15 Jan 2024 929th GolfingSuccess 🇬🇷 691 63 374ms 30 Jan 2024 931st JDiLenarda 🇫🇷 690 61 1,207ms 9 Oct 2020 932nd inventshah 690 70 2ms 9 Sep 2022 933rd jared-hughes 690 100 52ms 20 Jul 2022 934th labster 689 45 102ms 23 Feb 2018 934th snoozingnewt 🇨🇦 689 45 95ms 30 Nov 2025 936th MeWhenI 🇻🇦 689 75 35ms 20 Jun 2022 937th gnuvince 688 32 9ms 2 Aug 2024 937th codereport 🇨🇦 688 32 3ms 21 Apr 2025 939th marshallward 🇺🇸 688 81 39ms 2 Sep 2022 940th JayXon 🇺🇸 688 102 7ms 15 Mar 2023 941st PatrickStephansen 🇿🇦 686 72 13ms 3 Nov 2020 941st KatieLG 🇬🇧 686 72 11ms 16 Apr 2021 941st neihousaigaai 686 72 14ms 18 Apr 2021 941st two-bad 🇬🇧 686 72 11ms 25 Feb 2024 945th rustyflamingo 685 49 530ms 22 Sep 2022 945th antimon2 🇯🇵 685 49 530ms 15 Oct 2022 945th alemelis 685 49 502ms 1 Mar 2023 945th HPWiz 🇳🇿 685 49 514ms 9 Mar 2023 945th ovs-code 🇩🇪 685 49 530ms 24 Oct 2023 945th MarcMush 🇫🇷 685 49 490ms 5 Jan 2024 945th DialFrost 🇸🇬 685 49 527ms 5 Jan 2024 945th twolfive 685 49 492ms 5 Oct 2024 953rd DialFrost 🇸🇬 685 93 36ms 16 Feb 2025 954th galloj 🇨🇿 684 107 1ms 28 Aug 2022 955th j-Ewan 683 40 33ms 22 Feb 2022 956th Espiobest 683 69 15ms 26 Feb 2021 956th cbondurant 683 69 9ms 10 May 2021 956th hellwue 683 69 9ms 8 Feb 2023 956th Vaekor 683 69 9ms 9 Jul 2023 956th jatloe 683 69 80ms 27 Sep 2024 First Prev 881–960 of 3,204 Next Last