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?
12 Days of Christmas 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 800th argusdusty 🇺🇸 875 469 9ms 25 Dec 2020 800th jacklynnepenick 875 469 10ms 10 Aug 2021 800th Thestralos 875 469 10ms 24 Feb 2023 800th quimey 875 469 10ms 23 Mar 2023 800th keegan-t 🇨🇦 875 469 10ms 20 Sep 2023 800th Entropite 875 469 10ms 20 Aug 2024 800th croc54 875 469 10ms 13 Dec 2024 800th Pyroan 875 469 9ms 22 Feb 2025 800th now4est 🇯🇵 875 469 10ms 24 Sep 2025 800th dvckyduck 🇧🇬 875 469 11ms 7 Feb 2026 811th thomas-saigre 875 475 296ms 26 Nov 2024 812th nwellnhof 🇩🇪 875 485 1ms 9 Oct 2020 812th inventshah 875 485 1ms 13 Jul 2023 814th SubsTheTechnomancer 875 500 1ms 1 Mar 2023 814th snoozingnewt 🇨🇦 875 500 1ms 23 Sep 2023 814th neel11235813 875 500 1ms 26 Mar 2024 814th synt7x 🇺🇸 875 500 1ms 5 Jul 2025 818th neel11235813 875 510 90ms 16 Mar 2024 818th snoozingnewt 🇨🇦 875 510 88ms 30 Apr 2024 818th dokutan 875 510 86ms 23 Sep 2024 821st scottpenn 875 528 132ms 4 Jan 2020 822nd alphafalfa 874 464 1ms 16 Apr 2025 823rd KrausRaus 🇺🇸 874 465 4ms 18 Jul 2025 824th Giga-Bowser 874 466 11ms 4 Jan 2022 824th draem 874 466 11ms 31 Jul 2024 824th c-py 874 466 9ms 1 Nov 2025 824th tomh1012 874 466 10ms 3 Dec 2025 824th egertaia 874 466 10ms 9 Jan 2026 829th dokutan 874 484 485ms 27 Dec 2025 830th annaproxy 874 485 392ms 5 May 2022 831st kylelemons 874 528 269ms 16 Apr 2020 832nd snoozingnewt 🇨🇦 874 543 31ms 15 Oct 2025 833rd SirBogman 🇺🇸 874 691 12ms 23 Nov 2022 833rd frankgraziano 874 691 13ms 9 Feb 2026 835th emgordon154 873 460 432ms 14 Apr 2025 836th zdzc 873 470 10ms 3 Feb 2018 836th celynw 873 470 9ms 26 Dec 2018 836th petroselo 873 470 10ms 11 Apr 2022 836th Just4FunCoder 873 470 10ms 26 Oct 2022 836th PATTRIM 873 470 9ms 4 Jan 2023 836th mbittner20 873 470 10ms 8 Feb 2023 836th 2011-Chan-Ethan 873 470 10ms 9 Jul 2023 836th GeneralPoxter 873 470 10ms 7 Dec 2023 836th cuboids 873 470 10ms 16 Jul 2024 836th thoraage 873 470 10ms 21 Oct 2024 836th starfihs 873 470 9ms 28 Dec 2024 836th To5BG 873 470 10ms 16 Nov 2025 836th iliaspapa 873 470 9ms 10 Dec 2025 836th tomh1012 873 470 10ms 24 days ago 850th dokutan 873 482 166ms 17 Oct 2024 851st MostParsingVex 873 486 1ms 28 Dec 2024 852nd Echriser 873 510 294ms 14 Nov 2022 853rd eiburns 873 523 547ms 13 Nov 2020 853rd Vaekor 873 523 430ms 9 Jul 2023 853rd coltraloz 🇪🇸 873 523 399ms 22 Apr 2024 853rd snoozingnewt 🇨🇦 873 523 513ms 3 Oct 2025 857th 0xjac 🇨🇭 873 529 304ms 15 Jun 2020 857th klixel 🇨🇦 873 529 160ms 4 Jun 2023 857th CaedenHarper 🇨🇦 873 529 293ms 20 Nov 2025 860th Michaelncallahan 872 447 30ms 17 Apr 2020 860th Haksell 🇦🇶 872 447 34ms 22 Feb 2023 862nd northvandrew 872 457 276ms 8 Jun 2020 863rd Natanaelel 🇸🇪 872 467 9ms 11 Sep 2021 863rd SirBogman 🇺🇸 872 467 10ms 10 Dec 2021 863rd GeorgeStechman 🇬🇧 872 467 10ms 20 Sep 2022 863rd DayDun 🇸🇪 872 467 9ms 19 Jan 2023 863rd strattonwhisler 872 467 10ms 27 Mar 2025 863rd Andrey-Plotnikov 872 467 10ms 27 Jun 2025 863rd Yax42 🇫🇷 872 467 10ms 13 Feb 2026 870th PiterAnnema 872 471 10ms 30 Aug 2020 870th wirewolf010 872 471 10ms 3 Jan 2022 870th CedricGebistorf 872 471 10ms 25 Feb 2022 870th jmerle 🇳🇱 872 471 10ms 22 Jun 2023 870th JunkIce 872 471 10ms 24 Sep 2024 870th lukelarson 872 471 10ms 22 Apr 2025 870th smaass 872 471 10ms 12 Jul 2025 870th jacklee1792 872 471 11ms 6 Aug 2025 878th janbehrens 🇩🇪 872 486 393ms 21 Nov 2021 878th SubsTheTechnomancer 872 486 390ms 28 Feb 2023 878th snoozingnewt 🇨🇦 872 486 404ms 23 Sep 2023 First Prev 801–880 of 4,081 Next Last