The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 8 days. Why not try and solve them ahead of time?
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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 881st NewDefectus 🇮🇱 662 46 2ms 14 Jan 2022 882nd Shanethegamer 🇺🇸 661 86 4ms 14 Aug 2024 883rd BloodStormKnight 661 107 10ms 15 Oct 2022 883rd LukeBridges 🇬🇧 661 107 15ms 8 Nov 2022 883rd hacker112 🇸🇪 661 107 21ms 24 Jun 2024 886th akshatj27 🇦🇶 660 68 35ms 10 Jan 2022 886th Haksell 🇦🇶 660 68 37ms 23 Feb 2023 888th Lv0Sys 🇵🇱 660 197 41ms 13 Dec 2025 889th jhpaques 🇫🇷 659 131 2ms 13 Dec 2022 890th madex 🇩🇪 659 183 154ms 7 Aug 2025 891st HumanoidCPU 658 107 2,771ms 3 Mar 2025 892nd Bonjour27891 🇻🇳 657 105 19ms 15 Jul 2022 892nd stefangimmillaro 657 105 10ms 26 Dec 2022 892nd betaveros 657 105 9ms 1 Jan 2023 892nd 5cw 🇺🇸 657 105 10ms 3 May 2023 892nd minhtrancccp 657 105 10ms 26 Sep 2023 897th DialFrost 🇸🇬 657 116 10ms 12 Dec 2024 898th heanyang1 657 140 2ms 21 May 2025 899th The-Wolfson 656 157 108ms 16 Dec 2024 900th dokutan 655 133 2ms 10 Nov 2025 901st dokutan 654 132 1ms 13 Aug 2024 901st gonengazit 654 132 2ms 13 Apr 2025 903rd Yewzir 🇧🇪 654 139 375ms 24 Feb 2023 904th jhpaques 🇫🇷 653 199 41ms 13 Dec 2022 905th HumanoidCPU 652 118 412ms 3 Mar 2025 906th Anonymousellama21 652 141 2ms 14 Apr 2022 907th Bulmenisaurus 651 106 10ms 2 Feb 2025 908th jared-hughes 650 40 42ms 29 Jul 2022 909th 4hg 🇺🇸 650 69 35ms 30 Nov 2022 909th Andriamanitra 🇫🇮 650 69 39ms 17 Apr 2023 911th cbrt-x 650 164 447ms 16 Jan 2022 912th HumanoidCPU 649 186 156ms 4 Mar 2025 913th MeWhenI 🇻🇦 648 47 2ms 11 Jan 2022 914th KevinMarquette 🇺🇸 648 85 292ms 17 Apr 2022 914th snoozingnewt 🇨🇦 648 85 288ms 20 Nov 2023 916th xyangst 648 109 10ms 7 Oct 2024 916th snoozingnewt 🇨🇦 648 109 11ms 9 Oct 2025 918th akamayu-ouo 🇹🇼 647 142 1ms 8 Jul 2024 918th FoxInTheClouds 647 142 2ms 20 Feb 2026 920th saito-ta 🇯🇵 645 102 22ms 1 Jul 2022 921st fourth-bit 645 107 10ms 10 Jul 2024 921st fuzzylojik-golf 🇺🇸 645 107 10ms 19 May 2025 921st solisolu 645 107 10ms 25 Nov 2025 924th DialFrost 🇸🇬 644 117 109ms 18 Jun 2024 925th BREMAUCY 🇫🇷 644 202 41ms 14 Feb 2025 926th mckymsh 643 110 13ms 17 Feb 2024 926th madex 🇩🇪 643 110 10ms 6 Jun 2024 926th madeforlosers 643 110 10ms 13 Sep 2024 926th gigaprofisi 🇺🇸 643 110 9ms 4 Sep 2025 930th Re-Adventures 🇮🇳 643 143 2ms 7 Feb 2022 930th DrPiranoid 643 143 2ms 21 Oct 2022 932nd SirBogman 🇺🇸 642 96 450ms 16 Jan 2024 932nd Jacob385 642 96 428ms 13 Nov 2024 934th jwhear 🇺🇸 642 188 149ms 9 May 2023 935th denkyuu1 641 70 36ms 18 Feb 2026 936th MeWhenI 🇻🇦 640 110 2,688ms 24 Oct 2024 937th emgordon154 640 126 5ms 20 Feb 2025 938th MeWhenI 🇻🇦 639 96 130ms 25 Oct 2024 939th prplz 🇦🇺 639 108 10ms 11 Jan 2022 939th galloj 🇨🇿 639 108 10ms 21 Sep 2022 939th TaserTheFox 🇺🇸 639 108 9ms 3 Apr 2023 939th cros107 🇦🇺 639 108 10ms 10 Aug 2025 943rd astdefu 639 173 499ms 9 Dec 2022 944th jwhear 🇺🇸 639 230 1,707ms 30 Sep 2024 944th msbranicky 639 230 1,673ms 17 Sep 2025 946th sjrct 638 144 2ms 4 Aug 2024 947th bwat2 638 167 433ms 13 Jan 2022 947th rifatx 638 167 444ms 23 Jul 2024 949th albanian-laundromat 638 367 11ms 5 Dec 2025 950th Natanaelel 🇸🇪 636 62 32ms 21 Jun 2022 951st m-tkach 🇺🇦 636 121 387ms 10 Jan 2022 951st arctouch-cristiannevianna 636 121 394ms 1 Mar 2024 951st acer-xq 636 121 394ms 5 Aug 2024 954th edsrzf 🇳🇿 634 41 41ms 3 Nov 2025 955th dokutan 634 48 2ms 15 Nov 2024 956th biocommando 🇫🇮 634 145 2ms 26 Dec 2022 956th kallmi28 🇨🇿 634 145 2ms 13 Oct 2023 956th rifatx 634 145 1ms 14 Jul 2024 959th dokutan 634 205 39ms 31 Oct 2024 960th cefqrn 633 109 10ms 24 Dec 2022 First Prev 881–960 of 1,609 Next Last