The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 6 days. Why not try and solve them ahead of time?
Foo Fizz Buzz Bar 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 638th Jaykul 871 75 269ms 12 May 2024 642nd SirBogman 🇺🇸 871 90 1ms 29 Oct 2022 642nd dokutan 871 90 2ms 16 Jul 2025 644th sean-niemann 🇺🇸 871 91 8ms 29 May 2025 645th Maashau 871 142 448ms 9 Dec 2025 645th amazingalek 🇳🇴 871 142 480ms 17 Dec 2025 645th Florian-Mt 871 142 464ms 8 Jan 2026 648th dokutan 870 71 136ms 3 Oct 2024 649th primo-ppcg 🇹🇭 870 86 6ms 16 Aug 2023 650th ovs-code 🇩🇪 870 88 3ms 11 Oct 2023 651st frosster 🇨🇦 870 116 3ms 7 Feb 2026 652nd MeWhenI 🇻🇦 870 131 3ms 15 Jul 2023 653rd SirBogman 🇺🇸 869 137 441ms 1 Jan 2022 654th Re-Adventures 🇮🇳 868 92 6ms 7 Jul 2023 654th oddvalue 868 92 5ms 4 Aug 2023 656th yzhs 🇩🇪 868 109 129ms 16 Jun 2022 657th djeedjay 🇳🇱 868 111 3ms 3 Nov 2023 658th primo-ppcg 🇹🇭 868 149 3ms 22 Nov 2021 658th orthoplex 🇨🇽 868 149 4ms 8 Sep 2023 658th SirBogman 🇺🇸 868 149 4ms 20 Oct 2023 658th UnderKoen 🇳🇱 868 149 3ms 9 Feb 2025 662nd knyghty 867 75 11ms 17 Feb 2024 663rd dokutan 866 85 1,063ms 30 Aug 2025 664th Yax42 🇫🇷 866 106 443ms 6 Aug 2025 664th amazingalek 🇳🇴 866 106 467ms 7 Jan 2026 666th Shanethegamer 🇺🇸 865 71 38ms 30 Dec 2021 666th SirBogman 🇺🇸 865 71 37ms 21 May 2022 668th ovs-code 🇩🇪 865 120 474ms 4 Mar 2022 669th snoozingnewt 🇨🇦 865 143 439ms 16 Oct 2025 670th voidcoefficient 864 89 12ms 23 Nov 2021 670th inventshah 864 89 12ms 25 Nov 2021 670th TechNolaByte 864 89 11ms 26 Nov 2021 670th sleepyStick 864 89 11ms 4 Dec 2021 670th Giga-Bowser 864 89 12ms 6 Dec 2021 670th tristan-f-r 864 89 13ms 16 Dec 2021 670th tomisaacmarshall 864 89 11ms 26 Dec 2021 670th rbrdl 864 89 11ms 29 Dec 2021 670th ershadi-sayuri 864 89 10ms 13 Jan 2022 670th fitzdotlol 🇺🇸 864 89 12ms 18 Feb 2022 670th teofum 864 89 11ms 8 Mar 2022 670th sultan 864 89 12ms 13 Apr 2022 670th jb-lopez 🇺🇸 864 89 15ms 19 Apr 2022 670th ArekX 864 89 10ms 11 May 2022 670th jshji252 864 89 13ms 19 May 2022 670th solmyr2000 864 89 11ms 8 Jun 2022 670th maxpelic 🇺🇸 864 89 12ms 5 Jul 2022 670th vroup 🇩🇰 864 89 12ms 29 Sep 2022 670th CatsAreFluffy 864 89 11ms 22 Nov 2022 670th Nicronmil 864 89 11ms 24 Nov 2022 670th YPuest 864 89 11ms 20 Dec 2022 670th varhammer 864 89 14ms 2 Jan 2023 670th aksyristos 864 89 11ms 2 Jan 2023 670th amiralitaheri 864 89 18ms 14 Feb 2023 670th Isaac-NTT 864 89 11ms 23 Jun 2023 670th ollyspooner 864 89 11ms 27 Jul 2023 670th daniel-cardone 864 89 11ms 23 Aug 2023 670th Kamikadze4GAME 864 89 13ms 21 Sep 2023 670th guiohm 864 89 13ms 22 Oct 2023 670th derekthatcher 864 89 10ms 29 Nov 2023 670th Just4FunCoder 864 89 13ms 6 Dec 2023 670th Michiocre 864 89 13ms 20 Feb 2024 670th ggtylerr 864 89 11ms 18 Jun 2024 670th harcma 864 89 12ms 30 Jun 2024 670th Andrey-Plotnikov 864 89 10ms 23 Oct 2024 670th lifthrasiir 🇰🇷 864 89 10ms 15 Nov 2024 670th eTrey13 864 89 13ms 3 Feb 2025 670th malworthy 864 89 16ms 7 Mar 2025 670th smclaughlin-cf 864 89 11ms 20 Mar 2025 670th jake6192 864 89 14ms 16 May 2025 670th cloudyshoe 864 89 11ms 23 May 2025 670th acollett89 864 89 12ms 3 Jun 2025 670th 4very 864 89 13ms 7 Jun 2025 670th iczelia 🇩🇪 864 89 10ms 20 Oct 2025 670th junkondo-jp 864 89 12ms 9 Feb 2026 715th SirFireball3521 863 57 151ms 16 Mar 2023 716th sean-niemann 🇺🇸 863 79 312ms 12 Mar 2025 717th edsrzf 🇳🇿 863 116 43ms 6 Feb 2025 717th Steffan153 🇫🇮 863 116 42ms 12 Feb 2026 719th tailorspy 863 138 63ms 18 Sep 2024 720th SirBogman 🇺🇸 862 55 2ms 15 Dec 2023 First Prev 641–720 of 3,459 Next Last