The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 5 days. Why not try and solve them ahead of time?
Emirp 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 801st DialFrost 🇸🇬 710 77 2ms 15 Dec 2025 802nd msbranicky 709 78 82ms 14 Aug 2023 803rd Alex-x90 🇺🇸 709 100 58ms 16 Nov 2022 803rd sean-niemann 🇺🇸 709 100 72ms 29 Nov 2022 803rd fuzzylojik-golf 🇺🇸 709 100 61ms 6 Jul 2025 806th GolfingSuccess 🇬🇷 709 118 7ms 24 Feb 2026 807th retrohun 709 220 9ms 27 Dec 2022 808th emgordon154 703 64 2,700ms 26 Oct 2024 809th lynn 703 71 1,021ms 10 Nov 2021 810th handisb 703 80 12ms 25 Oct 2019 811th GrayJoKing 🇦🇺 703 81 2,261ms 30 Mar 2021 812th jarekwg 702 77 9ms 19 Apr 2019 812th chethus 702 77 10ms 10 May 2021 812th mokymok 🇺🇸 702 77 12ms 17 Nov 2021 812th StefanHabel 🇨🇦 702 77 10ms 26 Mar 2023 812th keelimeguy 🇺🇸 702 77 17ms 5 Nov 2024 817th sisyphus-ppcg 🇦🇺 702 101 55ms 23 Mar 2022 818th MeWhenI 🇻🇦 701 69 1,256ms 26 Oct 2021 819th primo-ppcg 🇹🇭 701 116 40ms 4 Jan 2024 820th Shanethegamer 🇺🇸 700 55 3ms 27 Dec 2021 821st lynn 700 57 36ms 25 May 2022 821st DialFrost 🇸🇬 700 57 34ms 26 Dec 2024 823rd Yewzir 🇧🇪 700 59 827ms 16 Nov 2025 824th Lydxn 🇨🇦 700 99 26ms 12 Mar 2022 825th Shanethegamer 🇺🇸 699 61 1,262ms 15 Dec 2022 825th anter69 🇭🇺 699 61 1,168ms 19 Feb 2023 827th primo-ppcg 🇹🇭 699 79 149ms 6 Sep 2023 828th edsrzf 🇳🇿 698 102 125ms 8 Jun 2025 829th j-Ewan 696 41 33ms 4 Feb 2022 829th yzhs 🇩🇪 696 41 35ms 23 Jun 2022 831st Indivicivet 696 53 105ms 23 Mar 2021 832nd yanqui-uxo 696 95 150ms 14 Sep 2018 832nd GrayJoKing 🇦🇺 696 95 150ms 16 Mar 2021 832nd Natanaelel 🇸🇪 696 95 145ms 11 Sep 2021 832nd stackofbears 696 95 151ms 7 Oct 2023 832nd HolmDev 696 95 138ms 10 Sep 2025 837th MichalMarsalek 🇨🇿 695 80 229ms 18 Dec 2022 837th fuzzylojik-golf 🇺🇸 695 80 228ms 31 Aug 2025 839th Waffle3z 695 81 12ms 5 Jun 2021 839th KrausRaus 🇺🇸 695 81 11ms 31 Dec 2021 839th inventshah 695 81 11ms 19 Jun 2022 842nd prplz 🇦🇺 694 82 5ms 10 Jul 2021 843rd stevelamm 693 78 9ms 3 Oct 2018 843rd Sticky-Bits 693 78 9ms 18 Apr 2019 843rd sk- 693 78 10ms 17 Sep 2019 843rd RDShah 693 78 11ms 3 Aug 2020 843rd hellwue 693 78 9ms 15 Feb 2023 843rd 2011-Chan-Ethan 693 78 15ms 20 Jul 2023 843rd davecame 693 78 9ms 14 Aug 2023 850th jared-hughes 693 98 511ms 24 Sep 2025 851st m-tkach 🇺🇦 693 100 25ms 18 Jun 2022 852nd Irratix 🇳🇱 691 80 141ms 17 Aug 2021 853rd anastos 689 96 146ms 23 Jul 2018 853rd user189032 689 96 146ms 29 May 2019 853rd yzhs 🇩🇪 689 96 155ms 24 Jul 2021 853rd cbrt-x 689 96 243ms 19 Sep 2023 853rd the-zammers 689 96 188ms 10 Nov 2023 858th dokutan 688 60 699ms 13 days ago 859th Yewzir 🇧🇪 688 62 1,214ms 7 Feb 2024 860th MeWhenI 🇻🇦 688 83 3ms 25 Jul 2023 861st stefangimmillaro 686 49 2ms 24 Apr 2022 862nd dokutan 686 81 227ms 23 Jul 2025 863rd stefangimmillaro 686 99 512ms 6 Oct 2025 864th GrayJoKing 🇦🇺 686 349 1ms 24 Jul 2020 865th janbehrens 🇩🇪 685 51 242ms 28 Nov 2023 865th dcgjb 685 51 254ms 9 Feb 2024 867th GeoffroyF 684 79 11ms 16 May 2018 867th Mr-Xcoder 684 79 10ms 8 Sep 2018 867th vladyslavprosolupov 684 79 10ms 27 May 2019 867th giacomogallina 684 79 33ms 13 Jun 2019 867th siegelzero 684 79 10ms 7 Aug 2019 867th handisb 684 79 16ms 26 Oct 2019 867th olivermrose 🇺🇸 684 79 11ms 20 Oct 2021 867th guilhem-roy 🇫🇷 684 79 17ms 26 Feb 2022 867th tri1212 🇻🇳 684 79 17ms 17 Jul 2022 867th P-Quentin 🇫🇷 684 79 13ms 3 Aug 2022 867th elgan65536 🇺🇸 684 79 16ms 7 Apr 2024 867th AlephSquirrel 684 79 10ms 19 Jul 2024 867th keegan-t 🇨🇦 684 79 16ms 23 Apr 2025 867th evan18c 684 79 16ms 23 Apr 2025 First Prev 801–880 of 3,185 Next Last