The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 8 mins. Why not try and solve them ahead of time?
Collatz 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 401st piano-miles 903 92 411ms 24 Feb 2026 402nd edsrzf 🇳🇿 902 52 1,067ms 22 days ago 403rd Betuaredead 902 60 4ms 5 Jan 2023 403rd Yewzir 🇧🇪 902 60 4ms 12 Feb 2023 403rd Steffan153 🇫🇮 902 60 4ms 23 Feb 2023 403rd GolfingSuccess 🇬🇷 902 60 4ms 16 Oct 2024 403rd sean-niemann 🇺🇸 902 60 9ms 7 Mar 2025 408th shellbertt 🇨🇦 902 62 20ms 4 May 2022 408th ZakkkkAttackkkk 🇵🇭 902 62 20ms 5 May 2022 408th annaproxy 902 62 21ms 8 Jun 2022 408th bob-th 902 62 20ms 9 Jul 2022 408th btjones0 902 62 25ms 15 Jul 2022 408th tri1212 🇻🇳 902 62 20ms 18 Jul 2022 408th fredrik-bakke 🇳🇴 902 62 19ms 5 Oct 2022 408th jakobkordez 🇸🇮 902 62 20ms 19 Oct 2022 408th Fishron 902 62 19ms 29 Nov 2022 408th KatieLG 🇬🇧 902 62 21ms 11 Dec 2022 408th ItsMeNoobieboy 902 62 20ms 20 Dec 2022 408th firegene 🇮🇪 902 62 20ms 3 Jan 2023 408th ljweel 902 62 20ms 13 Feb 2023 408th 2011-Chan-Ethan 902 62 19ms 9 Jul 2023 408th elgan65536 🇺🇸 902 62 20ms 18 Nov 2023 408th Dataen 902 62 21ms 16 Jan 2024 408th Yewzir 🇧🇪 902 62 48ms 5 Apr 2024 408th cuboids 902 62 21ms 11 Jul 2024 408th wuzekai518 902 62 24ms 26 Jul 2024 408th abhishekg999 902 62 52ms 17 Sep 2024 408th lifthrasiir 🇰🇷 902 62 20ms 16 Nov 2024 408th Artemis21 🇬🇧 902 62 18ms 17 Jan 2025 408th lolgeny 902 62 19ms 22 Feb 2025 408th keelimeguy 🇺🇸 902 62 21ms 15 May 2025 408th DoubleUynn 902 62 19ms 25 Jun 2025 433rd kg583 🇺🇸 902 77 18ms 20 days ago 434th edsrzf 🇳🇿 902 83 41ms 14 Jan 2025 434th kg583 🇺🇸 902 83 42ms 14 Feb 2025 436th GolfingSuccess 🇬🇷 901 64 91ms 14 Dec 2024 436th MeWhenI 🇻🇦 901 64 96ms 24 Dec 2024 436th GrayJoKing 🇦🇺 901 64 72ms 25 Nov 2025 439th Kacarott 🇦🇺 901 79 121ms 13 Jun 2024 440th stefangimmillaro 901 92 130ms 24 Oct 2023 440th inverseLorentz 🇦🇺 901 92 120ms 27 May 2024 440th sean-niemann 🇺🇸 901 92 129ms 8 Jun 2025 440th ian-h-chamberlain 🇺🇸 901 92 146ms 23 Nov 2025 444th michael-pruglo 🇺🇦 901 94 61ms 5 Jul 2022 444th zygoloid 901 94 60ms 5 Aug 2024 444th AdrienHache 🇫🇷 901 94 60ms 27 Dec 2025 447th Lydxn 🇨🇦 900 64 181ms 1 Apr 2023 448th MeWhenI 🇻🇦 899 63 197ms 5 May 2022 449th Lydxn 🇨🇦 898 49 37ms 4 May 2022 449th JayXon 🇺🇸 898 49 37ms 17 Oct 2022 449th GrayJoKing 🇦🇺 898 49 37ms 15 Nov 2022 449th radarek 🇵🇱 898 49 192ms 26 Aug 2025 453rd Lydxn 🇨🇦 898 70 96ms 7 May 2022 454th MeWhenI 🇻🇦 898 71 148ms 20 Aug 2024 455th m-tkach 🇺🇦 898 72 110ms 16 Oct 2022 455th GrayJoKing 🇦🇺 898 72 113ms 22 Oct 2022 455th emplv 🇱🇻 898 72 111ms 27 Oct 2022 455th sean-niemann 🇺🇸 898 72 172ms 7 Mar 2025 459th Steffan153 🇫🇮 898 82 42ms 1 Apr 2023 459th sean-niemann 🇺🇸 898 82 42ms 12 Jul 2024 461st albanian-laundromat 897 106 274ms 22 Dec 2025 462nd GrayJoKing 🇦🇺 896 74 66ms 1 Nov 2023 462nd DialFrost 🇸🇬 896 74 17ms 22 Feb 2026 462nd Steffan153 🇫🇮 896 74 17ms 22 Feb 2026 462nd GrayJoKing 🇦🇺 896 74 16ms 22 Feb 2026 462nd GolfingSuccess 🇬🇷 896 74 16ms 24 Feb 2026 462nd snoozingnewt 🇨🇦 896 74 16ms 27 days ago 462nd edsrzf 🇳🇿 896 74 16ms 22 days ago 469th Lydxn 🇨🇦 895 69 6ms 12 Sep 2022 469th GrayJoKing 🇦🇺 895 69 7ms 12 Sep 2022 469th btnlq 895 69 7ms 24 Sep 2022 469th trinityy-7 895 69 2ms 7 Aug 2025 473rd Steffan153 🇫🇮 894 67 112ms 18 Dec 2022 473rd Lydxn 🇨🇦 894 67 122ms 4 Feb 2023 473rd DialFrost 🇸🇬 894 67 101ms 17 Mar 2025 476th SirBogman 🇺🇸 893 50 516ms 5 May 2022 476th nwellnhof 🇩🇪 893 50 504ms 3 Jun 2022 476th Lydxn 🇨🇦 893 50 431ms 15 Aug 2022 476th Steffan153 🇫🇮 893 50 485ms 9 Aug 2024 480th NickTheEASDude 🇺🇸 893 76 6ms 7 May 2024 First Prev 401–480 of 3,628 Next Last