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?
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 emgordon154 814 86 11ms 29 Jul 2025 562nd ovs-code 🇩🇪 814 121 459ms 14 Jul 2023 563rd kaptsanovb 813 78 12ms 31 May 2023 563rd JunkIce 813 78 20ms 24 Nov 2024 563rd luuumine 🇫🇷 813 78 14ms 16 Oct 2025 566th GrayJoKing 🇦🇺 813 109 462ms 24 Jul 2025 567th Shanethegamer 🇺🇸 812 123 375ms 24 Sep 2025 568th clockworknazo 812 128 3ms 18 Sep 2022 569th Tine86 812 137 41ms 28 Jul 2025 570th stefangimmillaro 811 134 155ms 6 Nov 2023 571st ovs-code 🇩🇪 811 180 35ms 31 Mar 2023 572nd frankgraziano 811 241 13ms 25 Jun 2025 573rd retrohun 810 52 2ms 9 Nov 2022 574th alemelis 808 78 294ms 4 Mar 2024 575th roavin 807 101 419ms 23 Jun 2022 576th primo-ppcg 🇹🇭 807 113 40ms 26 Jun 2022 576th MeWhenI 🇻🇦 807 113 38ms 6 Sep 2022 576th sean-niemann 🇺🇸 807 113 42ms 24 Apr 2023 579th GrayJoKing 🇦🇺 807 140 178ms 8 Dec 2020 579th Hillsoft 807 140 166ms 27 Jul 2022 581st albanian-laundromat 807 224 1,484ms 15 Oct 2025 582nd clockworknazo 806 31 57ms 12 Aug 2022 583rd JulianJJ 806 79 12ms 7 Dec 2020 583rd xkacer 🇨🇿 806 79 13ms 31 Jan 2021 583rd Ephellon 806 79 12ms 4 Dec 2022 583rd Mazn3k 806 79 15ms 2 Mar 2023 583rd stefangabos 🇷🇴 806 79 12ms 14 May 2023 583rd jak-ch-ll 806 79 12ms 5 Jul 2025 589th b97tsk 806 153 310ms 26 Apr 2020 589th argusdusty 🇺🇸 806 153 291ms 21 Aug 2022 591st clockworknazo 805 76 10ms 10 Feb 2023 592nd solmyr2000 805 115 437ms 21 Jun 2022 593rd ovs-code 🇩🇪 805 135 157ms 21 Jun 2023 594th Steffan153 🇫🇮 804 74 8ms 2 Jul 2023 595th GrayJoKing 🇦🇺 804 96 110ms 9 Dec 2023 596th emgordon154 803 69 4ms 22 May 2025 597th RockOfStone 803 91 3ms 4 Nov 2021 598th janbehrens 🇩🇪 802 66 265ms 5 Dec 2023 599th hiichbindermax 802 79 19ms 25 Feb 2022 599th SB-945 802 79 20ms 30 Aug 2023 601st Steffan153 🇫🇮 802 126 79ms 6 days ago 602nd tatzyr 🇯🇵 801 55 37ms 24 Nov 2024 603rd Shanethegamer 🇺🇸 801 94 2,833ms 28 Oct 2024 603rd sean-niemann 🇺🇸 801 94 2,744ms 7 Jan 2026 605th janbehrens 🇩🇪 801 123 468ms 5 Dec 2023 606th Yewzir 🇧🇪 800 83 4ms 8 Jun 2024 606th rucin93 🇵🇱 800 83 4ms 23 Apr 2025 608th stefangimmillaro 800 139 42ms 26 Apr 2025 609th amazingalek 🇳🇴 799 102 455ms 1 Jan 2026 610th sean-niemann 🇺🇸 799 130 3ms 18 Jan 2025 611th SirBogman 🇺🇸 797 40 3ms 7 Feb 2024 612th dokutan 797 73 144ms 21 Mar 2025 613th ZakkkkAttackkkk 🇵🇭 797 91 2ms 6 Feb 2025 614th LukeBridges 🇬🇧 796 80 16ms 4 Nov 2022 614th AlephSquirrel 796 80 11ms 6 Jan 2023 614th junkondo-jp 796 80 11ms 2 Jun 2024 614th alexsave 796 80 11ms 7 Nov 2024 618th laikoni 796 142 177ms 21 Sep 2019 618th tobeannouncd 796 142 177ms 9 Jan 2024 620th yzzyx 796 155 271ms 18 Apr 2020 621st MeWhenI 🇻🇦 795 47 4ms 16 Apr 2023 622nd inventshah 795 82 75ms 14 Dec 2022 622nd sisyphus-ppcg 🇦🇺 795 82 76ms 27 Jan 2023 622nd ovs-code 🇩🇪 795 82 77ms 21 Mar 2024 622nd DialFrost 🇸🇬 795 82 99ms 17 Mar 2025 626th kg583 🇺🇸 795 88 30ms 1 Aug 2025 627th primo-ppcg 🇹🇭 793 75 9ms 4 Jul 2023 627th xsot 🇸🇬 793 75 10ms 13 Apr 2024 627th targrik 793 75 8ms 9 Sep 2025 630th MeWhenI 🇻🇦 793 131 3ms 10 Sep 2022 630th GrayJoKing 🇦🇺 793 131 3ms 11 Sep 2022 632nd lynn 793 137 165ms 31 Mar 2022 633rd edsrzf 🇳🇿 792 70 6ms 8 Nov 2025 634th KatieLG 🇬🇧 792 72 392ms 28 Oct 2024 635th MichaelMBradley 🇨🇦 792 80 13ms 9 Apr 2022 635th elgan65536 🇺🇸 792 80 19ms 31 Mar 2024 635th wh3n3v3r 🇨🇿 792 80 13ms 14 Nov 2024 638th raphaelimahorn 792 126 383ms 17 days ago 639th iznax 791 103 388ms 21 Nov 2021 640th Shanethegamer 🇺🇸 791 137 30ms 10 Feb 2026 First Prev 561–640 of 1,895 Next Last