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?
Roman to Arabic 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 879th StardustGogeta 521 138 27ms 6 Aug 2020 879th mcjo163 521 138 27ms 2 Sep 2020 883rd h3ra993huskp 🇯🇵 521 194 661ms 30 Nov 2025 884th blaztoma 🇱🇹 518 174 204ms 9 Nov 2025 885th retrohun 517 114 2,131ms 16 Aug 2025 886th Stockoh 🇫🇷 517 139 36ms 27 Feb 2024 886th te-chnical 517 139 26ms 8 Jan 2026 888th goodingc 517 219 162ms 3 Oct 2021 889th didion0 🇺🇸 515 147 18ms 23 Feb 2021 889th null-tangent 515 147 14ms 11 Sep 2022 889th junkondo-jp 515 147 16ms 22 Feb 2026 892nd CaedenHarper 🇨🇦 514 97 163ms 18 Aug 2025 893rd bwenstar 514 140 21ms 21 Feb 2024 894th jalone87 513 191 103ms 6 Feb 2020 895th jerrandolph 512 242 378ms 8 Nov 2023 896th tatzyr 🇯🇵 511 94 177ms 28 Dec 2024 897th rifatx 510 141 28ms 16 Mar 2023 897th quimey 510 141 22ms 20 Jul 2023 899th ian-h-chamberlain 🇺🇸 508 149 14ms 19 Dec 2019 899th shreyasminocha 508 149 14ms 2 Aug 2020 899th xnacly 🇩🇪 508 149 15ms 27 Jun 2023 902nd NewDefectus 🇮🇱 506 87 21ms 16 Oct 2021 902nd Natanaelel 🇸🇪 506 87 7ms 16 Nov 2021 902nd scpchicken 🇵🇼 506 87 19ms 24 Nov 2022 905th Haksell 🇦🇶 506 142 20ms 13 Jun 2020 905th Fishron 506 142 20ms 19 Sep 2022 905th jatloe 506 142 19ms 6 Sep 2024 908th HumanoidCPU 506 245 303ms 26 Aug 2024 909th neihousaigaai 505 200 567ms 18 May 2021 910th Brianzhengca 503 143 23ms 5 Feb 2021 910th TobyBoyne 🇬🇧 503 143 20ms 14 Apr 2022 912th orthoplex 🇨🇽 502 68 41ms 9 Oct 2020 913th emgordon154 502 198 41ms 22 days ago 914th JGDoerrer 502 200 455ms 5 Jan 2022 915th nyoshe 501 163 3ms 25 Jan 2025 916th celiendonze 🇨🇭 499 144 20ms 14 Apr 2023 916th Bulmenisaurus 499 144 19ms 1 Jul 2024 918th somebody1234 498 152 16ms 24 Mar 2018 918th tekaireb 498 152 16ms 24 Jul 2021 920th masinag 🇮🇹 498 164 3ms 25 Nov 2024 921st lmolteno 496 145 27ms 3 Mar 2021 921st guilhem-roy 🇫🇷 496 145 19ms 7 Mar 2022 921st frankgraziano 496 145 20ms 24 Apr 2025 921st TheZwierzLF 🇵🇱 496 145 18ms 21 May 2025 925th JDiLenarda 🇫🇷 496 193 1,420ms 30 Oct 2020 926th Stockoh 🇫🇷 494 131 560ms 24 Jun 2024 926th TheZwierzLF 🇵🇱 494 131 923ms 24 Nov 2025 928th jessegyger 494 153 15ms 7 Nov 2022 929th StarmaQ 494 181 13ms 7 Feb 2021 930th knightry 493 205 539ms 8 Feb 2021 931st CaedenHarper 🇨🇦 493 328 1,730ms 12 Oct 2025 932nd InigoK 🇺🇸 492 146 22ms 26 Aug 2025 933rd clementblaudeau 489 147 20ms 7 Jun 2021 933rd yuchuehw 489 147 20ms 3 Jan 2024 935th brimstonetrader 487 228 325ms 27 Mar 2024 936th yokasuretsu 486 148 26ms 21 Apr 2018 936th AgathokakologicalBit 486 148 27ms 3 Aug 2019 936th TaserTheFox 🇺🇸 486 148 21ms 8 May 2023 936th adamnielson42 🇺🇸 486 148 21ms 8 Aug 2023 936th jtaxen 486 148 18ms 28 Apr 2024 936th o0BlackDragon0o 486 148 26ms 8 Sep 2024 936th Bombalech 486 148 27ms 8 Sep 2024 943rd b10011 🇫🇮 483 149 34ms 12 Jun 2023 944th postie77 482 162 444ms 16 Mar 2023 945th Natanaelel 🇸🇪 481 71 41ms 16 Nov 2021 945th 4hg 🇺🇸 481 71 46ms 19 Jun 2024 947th bac0id 481 209 473ms 11 Jan 2025 948th alphafalfa 479 131 91ms 1 Aug 2025 949th sambirnbaum1 479 150 20ms 6 Sep 2019 949th MaxElf999 479 150 28ms 20 Oct 2022 949th nstearns96 🇬🇧 479 150 26ms 8 Dec 2022 949th Florian-Mt 479 150 21ms 14 Nov 2023 949th FoxInTheClouds 479 150 18ms 10 Feb 2026 954th pranaygp 479 158 15ms 13 May 2020 955th ian-h-chamberlain 🇺🇸 476 151 23ms 17 Dec 2019 955th qwjhvbxi 476 151 19ms 7 Feb 2024 957th SpareManiKatti 476 159 13ms 11 Sep 2021 957th blaztoma 🇱🇹 476 159 15ms 16 Sep 2025 959th olleicua 🇺🇸 475 101 101ms 25 Feb 2025 960th tailorspy 474 212 65ms 13 Sep 2024 First Prev 881–960 of 1,509 Next Last