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?
Forsyth–Edwards Notation in all languages in bytes. 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 Bytes Time Submitted 235th snoozingnewt 🇨🇦 834 137 10ms 20 Feb 2026 235th dokutan 834 137 10ms 14 days ago 235th aksyristos 834 137 10ms 13 hours ago 244th edsrzf 🇳🇿 834 168 2ms 26 Jul 2025 245th voytxt 🇨🇿 833 134 15ms 26 Nov 2025 246th ovs-code 🇩🇪 833 145 62ms 3 Jun 2024 246th sean-niemann 🇺🇸 833 145 65ms 6 Jan 2026 248th albanian-laundromat 833 336 1,492ms 24 Oct 2025 249th nwellnhof 🇩🇪 832 121 1ms 6 May 2023 250th emgordon154 831 102 1,176ms 11 Aug 2024 251st jared-hughes 830 283 8ms 7 Jul 2024 252nd snoozingnewt 🇨🇦 829 138 101ms 5 Dec 2025 253rd edsrzf 🇳🇿 829 147 3ms 22 Nov 2025 254th m-tkach 🇺🇦 828 117 515ms 21 Jan 2024 254th b-illy 🇬🇧 828 117 480ms 14 Jun 2025 256th Shanethegamer 🇺🇸 828 159 495ms 14 Jul 2023 257th Steffan153 🇫🇮 827 128 403ms 9 Aug 2024 258th tayloia 🇬🇧 827 135 10ms 2 May 2023 258th thisishowmymindworks 🇳🇴 827 135 10ms 6 Jun 2023 258th jared-hughes 827 135 9ms 28 Jul 2023 258th Argeento 🇵🇱 827 135 9ms 8 Sep 2023 258th Andrey-Plotnikov 827 135 11ms 26 Sep 2025 258th Lv0Sys 🇵🇱 827 135 10ms 8 Dec 2025 264th the-zammers 827 160 122ms 10 Nov 2023 264th tobeannouncd 827 160 127ms 12 Jan 2024 266th stefangimmillaro 827 164 674ms 6 Oct 2025 266th ScottHamper 827 164 500ms 30 Nov 2025 268th Waffle3z 826 155 1ms 14 Sep 2023 268th edsrzf 🇳🇿 826 155 2ms 22 Aug 2025 270th lynn 826 210 353ms 10 Nov 2025 271st albanian-laundromat 824 83 36ms 31 Oct 2025 272nd edsrzf 🇳🇿 824 201 25ms 29 Apr 2025 273rd primo-ppcg 🇹🇭 824 331 11ms 3 Aug 2023 274th emgordon154 822 139 9ms 19 May 2025 275th sisyphus-ppcg 🇦🇺 821 131 6ms 23 Nov 2023 276th DialFrost 🇸🇬 821 136 10ms 14 Jan 2024 277th Shanethegamer 🇺🇸 821 156 1ms 5 May 2023 278th alemelis 817 106 1,088ms 5 Oct 2024 279th DialFrost 🇸🇬 817 128 23ms 1 Mar 2025 280th ahmetdemirag 🇨🇾 817 140 10ms 30 Oct 2024 280th InigoK 🇺🇸 817 140 10ms 10 Sep 2025 282nd duckyluuk 🇳🇱 816 151 10ms 14 Jan 2025 283rd CaedenHarper 🇨🇦 815 137 14ms 23 Aug 2025 284th sean-niemann 🇺🇸 815 196 273ms 28 Aug 2023 285th olleicua 🇺🇸 814 84 34ms 13 May 2025 286th Steffan153 🇫🇮 814 119 470ms 17 Jan 2024 287th DialFrost 🇸🇬 813 162 490ms 5 Jun 2024 288th kg583 🇺🇸 812 191 45ms 7 days ago 289th rschwa6308 🇺🇸 811 141 16ms 5 May 2023 289th zbreit 🇺🇸 811 141 17ms 5 May 2023 289th neel11235813 811 141 9ms 25 Oct 2023 289th MeWhenI 🇻🇦 811 141 11ms 26 Feb 2025 293rd Shanethegamer 🇺🇸 811 161 394ms 3 May 2023 294th typeswitch-dev 🇵🇹 810 161 3ms 1 Sep 2023 295th JDiLenarda 🇫🇷 810 181 1,419ms 26 Jun 2025 296th Steffan153 🇫🇮 810 197 33ms 9 May 2023 297th WilliamDeBlieck 809 128 77ms 27 days ago 298th Irratix 🇳🇱 809 138 9ms 27 May 2023 299th emgordon154 809 346 1,463ms 9 Mar 2025 299th Shanethegamer 🇺🇸 809 346 1,820ms 14 Apr 2025 301st ericlangedijk 🇸🇮 808 131 417ms 22 May 2023 302nd edsrzf 🇳🇿 806 182 1,381ms 18 Jun 2025 303rd GolfingSuccess 🇬🇷 805 142 10ms 1 May 2023 303rd janbehrens 🇩🇪 805 142 10ms 1 May 2023 303rd MichalMarsalek 🇨🇿 805 142 10ms 1 May 2023 303rd inventshah 805 142 10ms 3 May 2023 303rd doktoren 805 142 10ms 7 Dec 2023 303rd anter69 🇭🇺 805 142 10ms 7 Oct 2024 303rd roguh 🇬🇹 805 142 9ms 15 Oct 2024 303rd KasperKivimaeki 🇫🇮 805 142 9ms 2 Nov 2025 311th SirBogman 🇺🇸 804 87 32ms 4 Dec 2023 312th JOrE20 804 139 11ms 22 Feb 2026 313th edsrzf 🇳🇿 804 200 44ms 7 Apr 2025 314th rucin93 🇵🇱 803 133 152ms 21 Feb 2025 315th GrayJoKing 🇦🇺 803 143 6ms 23 days ago 316th revlayle 🇺🇸 802 132 407ms 7 Jun 2023 316th AdrienHache 🇫🇷 802 132 424ms 28 Dec 2024 318th SirBogman 🇺🇸 801 73 2ms 4 Dec 2023 319th kg583 🇺🇸 800 121 410ms 6 Feb 2026 319th sean-niemann 🇺🇸 800 121 496ms 6 Feb 2026 First Prev 241–320 of 858 Next Last