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 400th Steffan153 🇫🇮 864 84 3ms 25 Apr 2023 400th nwellnhof 🇩🇪 864 84 2ms 27 Apr 2023 400th rhdqor213 864 84 3ms 11 Oct 2023 400th xsot 🇸🇬 864 84 3ms 30 Jan 2024 400th Alex-x90 🇺🇸 864 84 3ms 15 Feb 2024 400th sean-niemann 🇺🇸 864 84 3ms 25 Dec 2024 407th primo-ppcg 🇹🇭 863 58 1,365ms 8 Nov 2022 407th JayXon 🇺🇸 863 58 1,249ms 20 Feb 2023 409th lynn 863 131 177ms 24 Mar 2021 409th HPWiz 🇳🇿 863 131 178ms 22 Sep 2025 411th copy 862 37 3ms 12 Aug 2024 412th DialFrost 🇸🇬 862 57 9ms 27 Sep 2024 413th Steffan153 🇫🇮 862 71 5ms 9 Feb 2023 413th GrayJoKing 🇦🇺 862 71 5ms 1 Nov 2023 415th primo-ppcg 🇹🇭 862 143 298ms 18 Apr 2020 416th RobbertC5 860 74 16ms 20 May 2020 416th Maocx 860 74 13ms 21 May 2020 416th ArmaanAS 860 74 11ms 5 Feb 2021 416th MathisBullinger 860 74 12ms 16 Nov 2021 416th MadScience137 860 74 12ms 19 Oct 2022 416th coreynash 860 74 12ms 30 Nov 2023 422nd nwellnhof 🇩🇪 858 95 411ms 19 Apr 2023 422nd tomtheisen 🇺🇸 858 95 451ms 10 Feb 2025 424th commandz0 🇺🇸 857 74 13ms 22 Aug 2023 424th albanian-laundromat 857 74 14ms 14 Apr 2025 424th Flekay 🇩🇪 857 74 13ms 19 Jun 2025 424th Babafaba 857 74 13ms 10 Oct 2025 428th sean-niemann 🇺🇸 857 108 491ms 18 May 2022 428th inventshah 857 108 445ms 12 Jun 2022 430th edsrzf 🇳🇿 855 103 9ms 25 days ago 431st MeWhenI 🇻🇦 855 105 114ms 13 Aug 2022 431st sean-niemann 🇺🇸 855 105 117ms 26 Dec 2023 433rd SirBogman 🇺🇸 853 62 499ms 14 Jun 2024 434th JohandeRuiter 🇳🇱 853 85 2ms 14 Jul 2024 435th emgordon154 853 212 1,429ms 30 Mar 2025 436th JayXon 🇺🇸 852 180 1,723ms 22 Apr 2024 437th GrayJoKing 🇦🇺 851 93 5ms 20 Aug 2023 437th primo-ppcg 🇹🇭 851 93 5ms 20 Aug 2023 439th acodon 850 86 3ms 11 Jul 2019 439th DaDerpDuck 850 86 2ms 22 Jan 2021 441st arjanadriaanse 🇳🇱 850 133 178ms 15 Nov 2021 442nd moikaturns 🇬🇧 849 75 15ms 8 Dec 2022 442nd biocommando 🇫🇮 849 75 12ms 29 Dec 2022 444th Steffan153 🇫🇮 849 82 160ms 11 Jul 2024 445th Yax42 🇫🇷 849 96 463ms 17 Dec 2024 446th edsrzf 🇳🇿 849 118 115ms 28 Nov 2025 447th lifthrasiir 🇰🇷 849 172 51ms 13 Dec 2024 448th edsrzf 🇳🇿 848 59 1,289ms 30 Jan 2026 449th inventshah 847 58 7ms 14 May 2022 449th frankgraziano 847 58 9ms 25 Apr 2025 451st stefangimmillaro 847 106 109ms 7 Oct 2022 451st primo-ppcg 🇹🇭 847 106 108ms 12 Apr 2025 453rd DialFrost 🇸🇬 846 118 372ms 24 Sep 2025 453rd sean-niemann 🇺🇸 846 118 534ms 24 Sep 2025 453rd nwellnhof 🇩🇪 846 118 616ms 25 Sep 2025 453rd MeWhenI 🇻🇦 846 118 557ms 7 Nov 2025 453rd Steffan153 🇫🇮 846 118 414ms 11 Feb 2026 458th Steffan153 🇫🇮 846 128 27ms 25 days ago 459th yzhs 🇩🇪 845 75 14ms 25 Oct 2020 459th AdamHe17 845 75 13ms 31 May 2022 459th Artemis21 🇬🇧 845 75 14ms 10 Jan 2025 462nd marcin7Cd 845 87 24ms 8 Feb 2021 463rd MeWhenI 🇻🇦 845 89 111ms 15 Oct 2022 463rd Steffan153 🇫🇮 845 89 115ms 18 Oct 2022 463rd stefangimmillaro 845 89 113ms 21 Oct 2022 463rd sean-niemann 🇺🇸 845 89 118ms 25 May 2025 467th guliyevemil1 🇦🇿 845 146 289ms 16 Apr 2020 467th MeWhenI 🇻🇦 845 146 296ms 8 Feb 2023 469th sisyphus-ppcg 🇦🇺 843 50 2ms 3 Nov 2022 469th MeWhenI 🇻🇦 843 50 2ms 4 Nov 2022 469th Steffan153 🇫🇮 843 50 2ms 19 Dec 2022 469th DialFrost 🇸🇬 843 50 2ms 28 Jan 2023 473rd 09cf 843 86 2ms 16 Dec 2024 474th angel-p57 🇯🇵 843 120 4ms 11 Dec 2023 475th Shanethegamer 🇺🇸 843 134 180ms 7 Apr 2025 476th kg583 🇺🇸 842 94 5ms 29 Nov 2025 477th Shanethegamer 🇺🇸 842 117 515ms 19 Jan 2024 477th DialFrost 🇸🇬 842 117 467ms 2 Dec 2024 479th edsrzf 🇳🇿 842 120 77ms 5 days ago 480th primo-ppcg 🇹🇭 842 232 13ms 25 Jun 2025 First Prev 401–480 of 1,894 Next Last