The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 7 days. Why not try and solve them ahead of time?
12 Days of Christmas in Python 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 397th Omega65536 🇩🇪 846 488 10ms 23 Jun 2021 397th Sturla22 846 488 11ms 4 Apr 2022 397th HumanoidCPU 846 488 11ms 26 Mar 2024 397th BrunoVisnadi 🇧🇷 846 488 10ms 3 Oct 2025 397th Code-Coder-coder 846 488 9ms 11 Oct 2025 406th jgermain48 845 489 10ms 8 Dec 2019 407th ly0va 843 490 9ms 7 Jan 2019 407th chrismilson 843 490 10ms 18 May 2020 407th Jacob385 843 490 10ms 13 Mar 2024 407th rucin93 🇵🇱 843 490 9ms 26 Jul 2024 407th hippopotam00sehead 🇨🇦 843 490 10ms 16 Sep 2024 407th jbjd 843 490 10ms 17 Sep 2024 407th lelbal 843 490 10ms 19 Sep 2024 407th DraigRygbi 843 490 10ms 19 Dec 2024 407th argentite 843 490 10ms 11 Sep 2025 416th mikelane 841 491 10ms 29 Mar 2020 416th Jaydosu 841 491 10ms 22 Oct 2021 416th vishwathg 841 491 10ms 19 Aug 2022 416th grieve 841 491 9ms 9 Jun 2023 416th davidtiemstra 841 491 10ms 11 Jul 2023 416th Itnug 841 491 10ms 19 Jul 2023 416th Glinte 841 491 10ms 29 Dec 2023 416th fkantelberg 841 491 11ms 15 Jul 2025 416th cthierfelder 🇲🇨 841 491 10ms 5 Sep 2025 416th Matter1024 🇮🇳 841 491 10ms 3 days ago 426th GreenyNeko 839 492 10ms 24 Jul 2020 426th ydevor 🇮🇱 839 492 10ms 20 Nov 2020 426th michael-alperovich 839 492 9ms 1 Feb 2021 426th richard-oelze 🇩🇪 839 492 10ms 28 Nov 2021 426th MichaelMBradley 🇨🇦 839 492 10ms 5 Apr 2022 426th P-Quentin 🇫🇷 839 492 10ms 3 Aug 2022 426th DragonaireM 839 492 10ms 4 Feb 2023 426th ocean0821 839 492 10ms 7 May 2025 434th bthalheim 838 493 10ms 1 Aug 2022 434th TeddyWoodburn 838 493 29ms 6 Oct 2024 434th rothos 838 493 10ms 31 Dec 2024 434th M4rc0g1 838 493 11ms 16 Nov 2025 438th schachmattmatt 836 494 10ms 11 Aug 2021 438th specbug 836 494 10ms 30 Nov 2022 438th zsimo-lab49 836 494 10ms 15 May 2023 441st evanrittner 834 495 10ms 26 Feb 2021 441st Re-Adventures 🇮🇳 834 495 9ms 29 Mar 2021 441st kaptsanovb 834 495 10ms 4 Apr 2022 441st kenny14231 834 495 10ms 5 Aug 2022 441st OrangeBacon 834 495 10ms 31 Jul 2024 441st Unknownuserfrommars 834 495 9ms 7 Oct 2024 447th YoungjuneKwon 833 496 10ms 20 Nov 2020 447th asheeri 833 496 10ms 15 Aug 2021 447th ZakkkkAttackkkk 🇵🇭 833 496 30ms 25 Dec 2021 447th try-except-try-accept 🇹🇭 833 496 9ms 9 Jul 2022 447th ramsay 833 496 10ms 8 Aug 2022 447th jeaosh 833 496 10ms 22 Oct 2022 447th Starwort 🇬🇧 833 496 11ms 4 Dec 2022 447th fenix-bear 833 496 10ms 3 Jul 2023 447th htareque 833 496 30ms 18 Oct 2023 447th khavik 833 496 10ms 11 May 2024 447th yashima 833 496 9ms 4 Nov 2024 447th bogosorter 833 496 10ms 9 Jul 2025 447th celiendonze 🇨🇭 833 496 10ms 18 Dec 2025 460th btjones0 831 497 10ms 26 Dec 2020 460th vezzick 831 497 10ms 7 Mar 2021 460th kaylacomer 831 497 10ms 24 Oct 2021 460th MCausc78 🇺🇦 831 497 10ms 5 Jan 2023 460th ZoeyKD 831 497 9ms 14 May 2023 460th xoxo-ily 831 497 10ms 12 Dec 2023 460th aloobun 831 497 10ms 2 Dec 2024 467th SimonPeatman 829 498 10ms 29 Dec 2018 467th Arkaedan 829 498 9ms 27 Jul 2020 467th cesarm4 829 498 10ms 30 Aug 2021 467th GeneralTwi 829 498 10ms 4 May 2022 467th n0es 829 498 10ms 6 Oct 2022 467th saoudi-h 829 498 10ms 12 Jan 2023 467th adamnielson42 🇺🇸 829 498 9ms 30 May 2023 467th ArchFin 829 498 9ms 21 Nov 2024 467th GeneralFabian 829 498 31ms 14 Dec 2024 467th energee 829 498 10ms 19 Dec 2024 467th Europe2048 829 498 9ms 17 Sep 2025 467th muratovm 829 498 10ms 10 Dec 2025 479th orifu 828 499 9ms 22 Feb 2021 479th Bombergames 828 499 10ms 21 Jan 2022 First Prev 401–480 of 1,167 Next Last