The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 24 hours. Why not try and solve them ahead of time?
Happy Numbers (Long) 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 800th TaserTheFox 🇺🇸 795 88 21ms 28 Feb 2023 800th tobyLovick 795 88 21ms 12 Dec 2023 800th Dataen 795 88 301ms 12 Jan 2024 800th yuchuehw 795 88 20ms 28 Jan 2024 800th Masttest 795 88 20ms 13 Feb 2024 800th dirckvdende 795 88 392ms 2 Aug 2025 807th sisyphus-ppcg 🇦🇺 795 96 15ms 7 Apr 2022 807th DialFrost 🇸🇬 795 96 18ms 31 Oct 2024 807th sean-niemann 🇺🇸 795 96 21ms 9 Apr 2025 807th edsrzf 🇳🇿 795 96 12ms 26 Jul 2025 811th MeWhenI 🇻🇦 795 110 39ms 17 Feb 2023 812th Shanethegamer 🇺🇸 794 97 440ms 20 Jun 2022 812th billings7 🇬🇧 794 97 431ms 21 May 2024 812th Yax42 🇫🇷 794 97 462ms 7 Jan 2026 815th NewDefectus 🇮🇱 793 88 2ms 16 Dec 2021 816th mousetail 🇳🇱 791 55 19ms 15 Jan 2024 817th MeWhenI 🇻🇦 791 73 163ms 3 Aug 2024 818th steffan-polygolf 791 103 127ms 19 Feb 2024 819th albanian-laundromat 791 149 27ms 28 Dec 2025 820th janbehrens 🇩🇪 790 120 66ms 20 Nov 2022 820th oceko 790 120 66ms 19 Feb 2024 822nd albanian-laundromat 788 85 415ms 4 Dec 2025 823rd fuzzylojik-golf 🇺🇸 788 107 4ms 3 days ago 824th NickTheEASDude 🇺🇸 787 97 18ms 9 May 2024 825th Shanethegamer 🇺🇸 786 61 406ms 9 Mar 2023 826th TimHuisman1703 786 89 232ms 7 Jan 2022 826th Anonymousellama21 786 89 2,612ms 27 Jun 2022 826th yourlefthandman 786 89 277ms 17 Aug 2023 826th msbranicky 786 89 284ms 5 Oct 2023 826th luyckxrobbe 786 89 21ms 20 Nov 2023 826th rollershutter 786 89 301ms 2 Jul 2024 826th Mabeloid 🇳🇴 786 89 14ms 18 Sep 2024 826th jatloe 786 89 313ms 27 Sep 2024 834th MeWhenI 🇻🇦 786 105 440ms 17 Aug 2023 835th ian-h-chamberlain 🇺🇸 785 127 124ms 4 Dec 2025 836th ListeriaM 784 89 2ms 25 Aug 2023 837th snoozingnewt 🇨🇦 783 102 155ms 13 Sep 2025 838th prestosilver 🇺🇸 783 104 133ms 13 days ago 839th KenanSi 781 32 6ms 24 Feb 2022 839th ashtraypettingzoo 🇺🇸 781 32 6ms 5 Apr 2023 841st dokutan 781 93 3ms 17 days ago 842nd Shanethegamer 🇺🇸 780 74 162ms 19 Aug 2024 843rd Andrey2001 779 86 410ms 28 Jan 2026 844th frosster 🇨🇦 779 98 20ms 11 Feb 2026 845th aposteriorist 🇨🇦 779 106 452ms 5 Mar 2022 846th 2011-Chan-Ethan 777 90 330ms 12 Jul 2023 846th inverseLorentz 🇦🇺 777 90 304ms 3 May 2024 848th DialFrost 🇸🇬 777 104 9ms 20 days ago 849th Re-Adventures 🇮🇳 777 122 67ms 14 Aug 2022 850th yzhs 🇩🇪 776 39 36ms 21 Jun 2022 851st SirBogman 🇺🇸 776 48 386ms 4 Nov 2021 851st SirFireball3521 776 48 297ms 21 Mar 2023 853rd snoozingnewt 🇨🇦 776 105 123ms 3 Oct 2025 854th prplz 🇦🇺 775 64 1,317ms 20 Sep 2021 855th DialFrost 🇸🇬 773 127 115ms 29 Nov 2025 856th DialFrost 🇸🇬 773 129 160ms 5 Apr 2025 857th ovs-code 🇩🇪 772 127 27ms 26 Dec 2022 858th jared-hughes 771 77 11ms 14 Mar 2022 858th Re-Adventures 🇮🇳 771 77 11ms 14 Aug 2022 858th lyphyser 771 77 11ms 3 Jun 2023 858th helbling 🇨🇭 771 77 12ms 4 Jul 2024 862nd Shanethegamer 🇺🇸 771 93 14ms 8 Apr 2024 863rd FlyingPenguin223 770 62 52ms 16 Nov 2023 863rd Babafaba 770 62 35ms 15 Oct 2025 865th KatieLG 🇬🇧 770 111 169ms 14 Jan 2023 866th hjcafaroUC 768 91 20ms 26 Oct 2021 866th adoxography 768 91 20ms 18 Dec 2021 866th j-Ewan 768 91 19ms 16 Feb 2022 866th MaxElf999 768 91 21ms 29 Sep 2022 866th AlexanderFair 768 91 19ms 13 Jul 2023 866th chartung17 768 91 19ms 14 Jan 2024 866th NerdyMcNerd42 768 91 13ms 22 Mar 2024 873rd snoozingnewt 🇨🇦 768 92 2,590ms 27 Sep 2025 874th emgordon154 768 146 19ms 10 Jun 2025 875th NewDefectus 🇮🇱 767 64 50ms 21 Sep 2021 876th prplz 🇦🇺 767 91 2ms 19 Dec 2021 877th MeWhenI 🇻🇦 766 244 16ms 28 Aug 2023 878th strout 765 89 172ms 15 Aug 2022 879th jared-hughes 764 123 503ms 24 Sep 2025 879th Babafaba 764 123 440ms 14 Oct 2025 First Prev 801–880 of 2,106 Next Last