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 400th clockworknazo 863 34 49ms 31 Aug 2022 400th pardouin 🇫🇷 863 34 49ms 24 Oct 2024 403rd GrayJoKing 🇦🇺 863 75 3ms 12 Feb 2023 404th Garklein 🇨🇦 862 29 2ms 8 Jan 2025 405th Steffan153 🇫🇮 862 61 146ms 6 Aug 2024 406th primo-ppcg 🇹🇭 862 84 37ms 21 Jun 2022 407th weeble 861 44 3ms 16 Dec 2024 408th jared-hughes 861 66 2ms 17 Jul 2022 408th primo-ppcg 🇹🇭 861 66 2ms 19 Jul 2022 410th FlyingPenguin223 860 75 2ms 18 Mar 2025 411th phdphil 858 43 130ms 27 Apr 2018 412th kevinmchung 858 63 11ms 24 Feb 2018 412th tjtnorton 858 63 10ms 4 Dec 2018 412th leon-w 858 63 9ms 4 Jan 2019 412th hoodadam 858 63 9ms 5 Jul 2019 412th jcl5m1 858 63 9ms 27 Jul 2019 412th jared-hughes 858 63 9ms 7 Oct 2021 412th kellantech 858 63 10ms 3 Jun 2023 412th htareque 858 63 9ms 6 Oct 2023 412th zwxzwxzwx21 858 63 10ms 7 Feb 2024 421st stefangimmillaro 855 66 111ms 15 Jul 2023 422nd edsrzf 🇳🇿 852 141 76ms 7 days ago 422nd GolfingSuccess 🇬🇷 852 141 78ms 6 days ago 424th GrayJoKing 🇦🇺 850 46 62ms 13 Sep 2023 424th Lydxn 🇨🇦 850 46 63ms 13 Sep 2023 424th ovs-code 🇩🇪 850 46 63ms 13 Sep 2023 424th Steffan153 🇫🇮 850 46 66ms 16 Sep 2023 424th primo-ppcg 🇹🇭 850 46 65ms 16 Sep 2023 424th MeWhenI 🇻🇦 850 46 62ms 2 Nov 2023 424th Yewzir 🇧🇪 850 46 63ms 7 Mar 2024 424th pardouin 🇫🇷 850 46 61ms 26 Oct 2024 424th Shanethegamer 🇺🇸 850 46 67ms 27 Dec 2024 424th edsrzf 🇳🇿 850 46 61ms 17 Jan 2025 424th sean-niemann 🇺🇸 850 46 64ms 7 Apr 2025 424th fuzzylojik-golf 🇺🇸 850 46 61ms 17 Sep 2025 436th primo-ppcg 🇹🇭 849 57 1,248ms 11 May 2020 437th xsot 🇸🇬 849 59 370ms 14 May 2024 437th fuzzylojik-golf 🇺🇸 849 59 417ms 6 Jul 2025 439th msrawson 844 64 9ms 31 Aug 2018 439th mortimervonchappuis 844 64 10ms 17 Mar 2020 439th OllieBoyne 🇬🇧 844 64 9ms 30 Dec 2020 439th KatieLG 🇬🇧 844 64 11ms 6 May 2021 439th Fishron 844 64 17ms 19 Oct 2021 439th msbranicky 844 64 9ms 25 Jul 2023 439th jatloe 844 64 10ms 29 Oct 2024 439th ffelixm 844 64 10ms 12 Jun 2025 439th luuumine 🇫🇷 844 64 17ms 17 Nov 2025 439th Babafaba 844 64 11ms 17 Nov 2025 439th Flekay 🇩🇪 844 64 11ms 15 Feb 2026 450th nwellnhof 🇩🇪 844 84 55ms 18 Jan 2022 451st JayXon 🇺🇸 841 53 455ms 11 Nov 2022 452nd rak1507 🇬🇧 840 34 33ms 24 Oct 2021 453rd emplv 🇱🇻 840 67 12ms 13 Apr 2021 453rd vlpx 🇫🇮 840 67 11ms 18 Jun 2024 455th Shanethegamer 🇺🇸 840 143 3ms 7 Feb 2026 455th CaedenHarper 🇨🇦 840 143 2ms 6 days ago 455th dokutan 840 143 2ms 5 days ago 455th retrohun 840 143 3ms 5 days ago 459th sisyphus-ppcg 🇦🇺 839 35 48ms 26 Jul 2022 459th lynn 839 35 46ms 19 Oct 2023 461st UnderKoen 🇳🇱 838 89 1ms 1 Jul 2022 461st sisyphus-ppcg 🇦🇺 838 89 1ms 7 Jul 2022 461st m-tkach 🇺🇦 838 89 1ms 8 Mar 2023 461st edsrzf 🇳🇿 838 89 2ms 5 Mar 2025 465th primo-ppcg 🇹🇭 836 51 1,245ms 6 Jul 2021 466th SirBogman 🇺🇸 835 60 400ms 20 Jan 2024 466th Steffan153 🇫🇮 835 60 379ms 20 Jan 2024 466th Yewzir 🇧🇪 835 60 401ms 4 Feb 2024 466th m-tkach 🇺🇦 835 60 405ms 9 Apr 2024 466th sean-niemann 🇺🇸 835 60 387ms 27 Jul 2024 466th CaedenHarper 🇨🇦 835 60 424ms 21 Aug 2024 466th albanian-laundromat 835 60 431ms 4 Dec 2025 473rd Shanethegamer 🇺🇸 835 84 6ms 21 Mar 2023 474th HumanoidCPU 834 144 3ms 1 Jan 2026 474th KatieLG 🇬🇧 834 144 3ms 21 Feb 2026 476th inventshah 833 79 1ms 25 Jan 2023 476th Alex-x90 🇺🇸 833 79 2ms 27 Jan 2023 476th Yewzir 🇧🇪 833 79 1ms 22 Dec 2023 476th sean-niemann 🇺🇸 833 79 1ms 29 Jul 2024 476th pardouin 🇫🇷 833 79 1ms 5 Oct 2024 First Prev 401–480 of 3,185 Next Last