The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 6 days. Why not try and solve them ahead of time?
Christmas Trees in Python 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 556th ydevor 🇮🇱 568 95 9ms 21 Nov 2020 556th jotslo 🇬🇧 568 95 10ms 5 Jul 2021 556th scottwday 🇨🇦 568 95 10ms 23 Nov 2021 556th mhenion8293 🇺🇸 568 95 10ms 11 Jan 2022 556th martinnorling 🇸🇪 568 95 9ms 7 Mar 2022 556th karhuthebear 568 95 10ms 11 May 2022 556th pmooreh 568 95 10ms 18 Aug 2022 556th eshilo-draper 568 95 9ms 4 Sep 2022 556th MaxElf999 568 95 9ms 29 Sep 2022 556th dapexyz 568 95 9ms 12 Jan 2023 556th robertovers 568 95 10ms 20 Dec 2023 556th brimstonetrader 568 95 9ms 31 Jan 2024 556th qwjhvbxi 568 95 9ms 9 Feb 2024 556th IoLimmer 568 95 8ms 2 Jul 2024 556th Ythaenagor 568 95 10ms 5 Aug 2024 556th KAKISKA-code 🇫🇮 568 95 9ms 24 May 2025 556th SectorCorruptor 568 95 9ms 10 Feb 2026 578th Marcel-Brouette 563 96 10ms 14 Mar 2019 578th gtdlk20 563 96 9ms 6 Aug 2019 578th Akilles1 563 96 11ms 26 Nov 2019 578th SolidTux 563 96 10ms 6 Jan 2020 578th ArturLukianov 563 96 9ms 17 Dec 2020 578th jrm5399 🇰🇿 563 96 10ms 2 Nov 2021 578th joshmoody24 563 96 11ms 4 Mar 2022 578th ramsay 563 96 9ms 10 Aug 2022 578th DrPrettyman 563 96 9ms 3 Jul 2023 578th CameronGBell 563 96 10ms 23 Jan 2025 578th LordSir101 563 96 10ms 11 Aug 2025 578th Aquateraneal 🇺🇸 563 96 10ms 18 days ago 590th ly0va 557 97 9ms 6 Jan 2019 590th omgardner 557 97 9ms 28 Feb 2019 590th maxumusprime 557 97 9ms 18 Feb 2020 590th itsbjoern 557 97 9ms 8 Dec 2020 590th dgambit 557 97 9ms 2 Apr 2021 590th lukehatcher 🇺🇸 557 97 9ms 29 Aug 2021 590th danielweper 557 97 9ms 21 Oct 2021 590th borosilicate 557 97 10ms 6 May 2022 590th bthalheim 557 97 10ms 3 Sep 2022 590th n0es 557 97 10ms 18 Oct 2022 590th Glinte 557 97 9ms 15 Dec 2023 590th 123mjb 557 97 10ms 3 Jan 2024 590th damoose717 557 97 10ms 23 May 2025 603rd GiorgioBalestrieri 551 98 9ms 20 Mar 2019 603rd jamesbtan 551 98 11ms 25 Mar 2019 603rd ian-h-chamberlain 🇺🇸 551 98 10ms 14 Dec 2019 603rd Reyzartz 551 98 10ms 19 Sep 2020 603rd pvilimas 551 98 10ms 18 Feb 2021 603rd mamakram 551 98 9ms 20 Oct 2021 603rd katharine67 551 98 11ms 8 Oct 2022 603rd PotatoSaladOverlord 551 98 11ms 19 May 2023 603rd PedroAS7 551 98 9ms 18 Jun 2024 612th arnavb 545 99 11ms 6 Oct 2018 612th Cortan122 545 99 9ms 26 Feb 2019 612th shraiwi 545 99 12ms 12 Jul 2019 612th Theis24 545 99 10ms 27 Nov 2019 612th confy 545 99 9ms 27 Oct 2020 612th OppositeShark 545 99 10ms 19 Jul 2022 612th willdaspit 545 99 10ms 7 Aug 2023 612th TinyTheBrontosaurus 545 99 10ms 3 Dec 2023 612th roguh 🇬🇹 545 99 10ms 14 Jan 2024 612th ComputerKWasTaken 🇺🇸 545 99 9ms 31 May 2024 612th Ralac07 🇦🇺 545 99 10ms 4 Aug 2025 612th Voltrifrodec 🇸🇰 545 99 9ms 7 Nov 2025 624th fatcat2 540 100 9ms 4 Jan 2020 624th tomh1012 540 100 9ms 29 Oct 2020 624th try-except-try-accept 🇹🇭 540 100 10ms 27 Jun 2022 624th Pimveha 540 100 11ms 12 Jan 2023 624th Shiran-Yuan 540 100 10ms 5 Apr 2023 624th r-i-c-e 540 100 9ms 8 Jul 2023 624th ssbhatt4321 540 100 10ms 14 Oct 2023 624th alexjurkiewicz 🇦🇺 540 100 10ms 7 Nov 2023 624th tperr 540 100 10ms 29 Sep 2024 633rd cpt-John 535 101 10ms 25 Jun 2019 633rd MarkRdgOx 535 101 10ms 14 Jan 2020 633rd YoranDS 535 101 10ms 25 Nov 2021 633rd danielolson13 535 101 10ms 7 Aug 2022 633rd Azearia 535 101 9ms 27 Feb 2024 633rd MassimoParisi 535 101 10ms 23 Sep 2024 633rd matricronia 535 101 10ms 27 Jan 2026 640th derekthatcher 529 102 9ms 18 Sep 2020 First Prev 561–640 of 849 Next Last