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?
Prime 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 558th AlephSquirrel 918 35 4ms 20 Apr 2023 558th primo-ppcg 🇹🇭 918 35 3ms 27 Apr 2023 558th MeWhenI 🇻🇦 918 35 3ms 23 May 2023 558th GrayJoKing 🇦🇺 918 35 3ms 15 Aug 2023 558th btnlq 918 35 4ms 21 Oct 2023 558th Yewzir 🇧🇪 918 35 3ms 28 Oct 2023 558th Betuaredead 918 35 4ms 12 Nov 2023 558th edsrzf 🇳🇿 918 35 4ms 1 Nov 2024 558th emgordon154 918 35 3ms 22 Dec 2024 558th sean-niemann 🇺🇸 918 35 4ms 26 Apr 2025 558th kg583 🇺🇸 918 35 4ms 25 Sep 2025 572nd Lydxn 🇨🇦 918 46 10ms 15 Nov 2021 572nd lynn 918 46 9ms 15 Nov 2021 572nd btnlq 918 46 9ms 15 Nov 2021 572nd GrayJoKing 🇦🇺 918 46 9ms 16 Nov 2021 572nd Steffan153 🇫🇮 918 46 9ms 30 Oct 2022 572nd Yewzir 🇧🇪 918 46 8ms 11 Apr 2024 572nd ovs-code 🇩🇪 918 46 9ms 29 Jun 2024 572nd sean-niemann 🇺🇸 918 46 9ms 6 Apr 2025 580th yokasuretsu 917 12 33ms 8 Nov 2018 580th diddily 917 12 34ms 30 Oct 2019 580th BBoehm 🇩🇪 917 12 33ms 29 Dec 2020 580th Toanuvo 917 12 34ms 20 Jan 2022 580th saltysylvi 917 12 34ms 11 Oct 2022 580th jhonw 917 12 34ms 22 Sep 2023 580th alphafalfa 917 12 2ms 15 Jul 2024 580th plcc0 917 12 34ms 8 May 2025 580th aksyristos 917 12 36ms 13 Jan 2026 580th denkyuu1 917 12 34ms 23 Feb 2026 590th sean-niemann 🇺🇸 917 36 160ms 3 Aug 2024 590th Steffan153 🇫🇮 917 36 136ms 3 Aug 2024 590th JayXon 🇺🇸 917 36 139ms 4 Aug 2024 590th pardouin 🇫🇷 917 36 140ms 4 Aug 2024 590th lukegustafson 🇺🇸 917 36 138ms 4 Aug 2024 590th Lydxn 🇨🇦 917 36 136ms 6 Aug 2024 596th Lydxn 🇨🇦 917 40 134ms 18 Aug 2021 596th MeWhenI 🇻🇦 917 40 136ms 18 Aug 2021 596th JayXon 🇺🇸 917 40 137ms 18 Aug 2021 599th canissimia 🇦🇶 917 134 1ms 14 Jul 2021 600th MeWhenI 🇻🇦 916 29 5ms 16 Jul 2022 601st primo-ppcg 🇹🇭 916 34 1,022ms 6 May 2022 601st HPWiz 🇳🇿 916 34 1,022ms 6 May 2022 603rd Lydxn 🇨🇦 916 42 7ms 20 Dec 2023 603rd Steffan153 🇫🇮 916 42 6ms 9 Aug 2024 603rd sean-niemann 🇺🇸 916 42 6ms 19 Apr 2025 606th kg583 🇺🇸 916 53 5ms 8 Oct 2025 607th pardouin 🇫🇷 915 41 2,547ms 31 Oct 2024 607th btnlq 915 41 2,469ms 31 Oct 2024 607th JayXon 🇺🇸 915 41 2,579ms 7 Nov 2024 607th Steffan153 🇫🇮 915 41 2,375ms 13 Feb 2026 611th Lydxn 🇨🇦 915 42 81ms 15 May 2022 611th GrayJoKing 🇦🇺 915 42 78ms 16 May 2022 611th Steffan153 🇫🇮 915 42 76ms 10 Dec 2022 611th JayXon 🇺🇸 915 42 76ms 20 Mar 2023 611th Yewzir 🇧🇪 915 42 77ms 9 Nov 2023 611th Betuaredead 915 42 92ms 13 Nov 2023 611th pardouin 🇫🇷 915 42 79ms 3 Sep 2024 611th DialFrost 🇸🇬 915 42 73ms 14 Nov 2024 611th sean-niemann 🇺🇸 915 42 75ms 18 Apr 2025 611th albanian-laundromat 915 42 74ms 8 Nov 2025 621st Lydxn 🇨🇦 915 54 112ms 14 Oct 2022 621st JayXon 🇺🇸 915 54 115ms 13 Jun 2023 623rd HPWiz 🇳🇿 914 29 498ms 10 May 2023 623rd ovs-code 🇩🇪 914 29 499ms 24 Oct 2023 623rd Codsilla 🇨🇦 914 29 508ms 31 Oct 2023 623rd DialFrost 🇸🇬 914 29 535ms 5 Jan 2024 623rd Steffan153 🇫🇮 914 29 512ms 17 Aug 2024 623rd sean-niemann 🇺🇸 914 29 534ms 13 Mar 2025 629th saito-ta 🇯🇵 914 41 3ms 19 May 2023 630th saito-ta 🇯🇵 913 17 42ms 26 Jul 2022 630th clockworknazo 913 17 67ms 9 Aug 2022 632nd retrohun 913 43 15ms 5 Aug 2018 632nd Attero 🇸🇪 913 43 9ms 15 May 2020 632nd hashkitten 913 43 16ms 24 Sep 2020 632nd urojony 🇵🇱 913 43 9ms 28 Dec 2020 632nd 77Tigers 913 43 11ms 4 Mar 2021 632nd jacklynnepenick 913 43 11ms 14 Aug 2021 632nd annaproxy 913 43 10ms 7 Dec 2021 632nd emplv 🇱🇻 913 43 10ms 14 Dec 2021 632nd bob-th 913 43 10ms 5 Aug 2022 First Prev 561–640 of 5,508 Next Last