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?
Ordinal 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 561st ovs-code 🇩🇪 814 121 459ms 14 Jul 2023 562nd kaptsanovb 813 78 12ms 31 May 2023 562nd JunkIce 813 78 20ms 24 Nov 2024 562nd luuumine 🇫🇷 813 78 14ms 16 Oct 2025 565th GrayJoKing 🇦🇺 813 109 462ms 24 Jul 2025 566th Shanethegamer 🇺🇸 812 123 375ms 24 Sep 2025 567th clockworknazo 812 128 3ms 18 Sep 2022 568th Tine86 812 137 41ms 28 Jul 2025 569th stefangimmillaro 811 134 155ms 6 Nov 2023 570th ovs-code 🇩🇪 811 180 35ms 31 Mar 2023 571st frankgraziano 811 241 13ms 25 Jun 2025 572nd retrohun 810 52 2ms 9 Nov 2022 573rd alemelis 808 78 294ms 4 Mar 2024 574th roavin 807 101 419ms 23 Jun 2022 575th primo-ppcg 🇹🇭 807 113 40ms 26 Jun 2022 575th MeWhenI 🇻🇦 807 113 38ms 6 Sep 2022 575th sean-niemann 🇺🇸 807 113 42ms 24 Apr 2023 578th GrayJoKing 🇦🇺 807 140 178ms 8 Dec 2020 578th Hillsoft 807 140 166ms 27 Jul 2022 580th albanian-laundromat 807 224 1,484ms 15 Oct 2025 581st clockworknazo 806 31 57ms 12 Aug 2022 582nd JulianJJ 806 79 12ms 7 Dec 2020 582nd xkacer 🇨🇿 806 79 13ms 31 Jan 2021 582nd Ephellon 806 79 12ms 4 Dec 2022 582nd Mazn3k 806 79 15ms 2 Mar 2023 582nd stefangabos 🇷🇴 806 79 12ms 14 May 2023 582nd jak-ch-ll 806 79 12ms 5 Jul 2025 588th b97tsk 806 153 310ms 26 Apr 2020 588th argusdusty 🇺🇸 806 153 291ms 21 Aug 2022 590th clockworknazo 805 76 10ms 10 Feb 2023 591st solmyr2000 805 115 437ms 21 Jun 2022 592nd ovs-code 🇩🇪 805 135 157ms 21 Jun 2023 593rd Steffan153 🇫🇮 804 74 8ms 2 Jul 2023 594th GrayJoKing 🇦🇺 804 96 110ms 9 Dec 2023 595th emgordon154 803 69 4ms 22 May 2025 596th RockOfStone 803 91 3ms 4 Nov 2021 597th janbehrens 🇩🇪 802 66 265ms 5 Dec 2023 598th hiichbindermax 802 79 19ms 25 Feb 2022 598th SB-945 802 79 20ms 30 Aug 2023 600th Steffan153 🇫🇮 802 126 79ms 6 days ago 601st tatzyr 🇯🇵 801 55 37ms 24 Nov 2024 602nd Shanethegamer 🇺🇸 801 94 2,833ms 28 Oct 2024 602nd sean-niemann 🇺🇸 801 94 2,744ms 7 Jan 2026 604th janbehrens 🇩🇪 801 123 468ms 5 Dec 2023 605th Yewzir 🇧🇪 800 83 4ms 8 Jun 2024 605th rucin93 🇵🇱 800 83 4ms 23 Apr 2025 607th stefangimmillaro 800 139 42ms 26 Apr 2025 608th amazingalek 🇳🇴 799 102 455ms 1 Jan 2026 609th sean-niemann 🇺🇸 799 130 3ms 18 Jan 2025 610th SirBogman 🇺🇸 797 40 3ms 7 Feb 2024 611th dokutan 797 73 144ms 21 Mar 2025 612th ZakkkkAttackkkk 🇵🇭 797 91 2ms 6 Feb 2025 613th LukeBridges 🇬🇧 796 80 16ms 4 Nov 2022 613th AlephSquirrel 796 80 11ms 6 Jan 2023 613th junkondo-jp 796 80 11ms 2 Jun 2024 613th alexsave 796 80 11ms 7 Nov 2024 617th laikoni 796 142 177ms 21 Sep 2019 617th tobeannouncd 796 142 177ms 9 Jan 2024 619th yzzyx 796 155 271ms 18 Apr 2020 620th MeWhenI 🇻🇦 795 47 4ms 16 Apr 2023 621st inventshah 795 82 75ms 14 Dec 2022 621st sisyphus-ppcg 🇦🇺 795 82 76ms 27 Jan 2023 621st ovs-code 🇩🇪 795 82 77ms 21 Mar 2024 621st DialFrost 🇸🇬 795 82 99ms 17 Mar 2025 625th kg583 🇺🇸 795 88 30ms 1 Aug 2025 626th primo-ppcg 🇹🇭 793 75 9ms 4 Jul 2023 626th xsot 🇸🇬 793 75 10ms 13 Apr 2024 626th targrik 793 75 8ms 9 Sep 2025 629th MeWhenI 🇻🇦 793 131 3ms 10 Sep 2022 629th GrayJoKing 🇦🇺 793 131 3ms 11 Sep 2022 631st lynn 793 137 165ms 31 Mar 2022 632nd edsrzf 🇳🇿 792 70 6ms 8 Nov 2025 633rd KatieLG 🇬🇧 792 72 392ms 28 Oct 2024 634th MichaelMBradley 🇨🇦 792 80 13ms 9 Apr 2022 634th elgan65536 🇺🇸 792 80 19ms 31 Mar 2024 634th wh3n3v3r 🇨🇿 792 80 13ms 14 Nov 2024 637th raphaelimahorn 792 126 383ms 16 days ago 638th iznax 791 103 388ms 21 Nov 2021 639th Shanethegamer 🇺🇸 791 137 30ms 10 Feb 2026 640th TimCurwick 🇺🇸 790 67 311ms 29 Sep 2020 First Prev 561–640 of 1,894 Next Last