The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 3 hours. Why not try and solve them ahead of time?
Collatz 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 721st Shanethegamer 🇺🇸 881 142 1,441ms 27 Mar 2025 721st DialFrost 🇸🇬 881 142 1,421ms 28 Mar 2025 721st emgordon154 881 142 1,443ms 10 Apr 2025 721st GolfingSuccess 🇬🇷 881 142 1,431ms 6 Dec 2025 725th JayXon 🇺🇸 881 158 1,772ms 14 Sep 2025 726th dokutan 880 62 5ms 28 Apr 2025 727th johnnythedoggie 880 72 96ms 13 May 2022 727th kaascevich 880 72 96ms 8 Jul 2025 727th madeforlosers 880 72 102ms 14 days ago 730th CaedenHarper 🇨🇦 879 54 1,364ms 27 Sep 2025 730th sean-niemann 🇺🇸 879 54 1,464ms 27 Sep 2025 730th albanian-laundromat 879 54 1,533ms 14 Nov 2025 730th xsot 🇸🇬 879 54 1,352ms 15 Nov 2025 734th Shanethegamer 🇺🇸 878 66 172ms 4 May 2022 734th scpchicken 🇵🇼 878 66 254ms 5 May 2022 734th sisyphus-ppcg 🇦🇺 878 66 173ms 6 May 2022 734th Natanaelel 🇸🇪 878 66 144ms 15 Jun 2022 734th Z-snails 878 66 254ms 27 Feb 2023 734th Jeremy-Stafford 878 66 258ms 27 Feb 2023 734th alomiF 878 66 293ms 1 Sep 2023 734th btnlq 878 66 145ms 17 Oct 2023 734th Shengxuan-Zhang 878 66 278ms 20 Feb 2026 743rd DialFrost 🇸🇬 878 86 40ms 24 Oct 2024 743rd stefangimmillaro 878 86 39ms 14 Jan 2025 745th c0d3-4-F00d 🇩🇪 877 61 11ms 6 May 2022 745th jackkav 877 61 10ms 26 Jun 2022 745th TechNolaByte 877 61 10ms 6 Jul 2022 745th Heathcorp 🇦🇺 877 61 11ms 17 Jul 2022 745th C0de5mith 🇺🇸 877 61 11ms 3 Aug 2022 745th sebipopa 🇷🇴 877 61 11ms 18 Aug 2022 745th moikaturns 🇬🇧 877 61 10ms 25 Sep 2022 745th FlorianCassayre 🇫🇷 877 61 12ms 27 Sep 2022 745th Mazn3k 877 61 11ms 1 Feb 2023 745th tvcv901 877 61 11ms 22 Mar 2023 745th unfinishedprogram 877 61 11ms 19 Jul 2023 745th snoozingnewt 🇨🇦 877 61 11ms 23 Sep 2023 745th funnyboy-roks 877 61 11ms 9 May 2024 745th bac0id 877 61 10ms 29 Jun 2024 745th FortuiteMan 🇫🇷 877 61 11ms 10 Oct 2024 745th RobertHoeh 877 61 10ms 5 Apr 2025 745th LvLError 877 61 11ms 29 May 2025 745th miles-evan 877 61 10ms 5 Aug 2025 745th alexsave 877 61 10ms 13 Oct 2025 764th nwellnhof 🇩🇪 876 53 7ms 4 May 2022 764th GrayJoKing 🇦🇺 876 53 7ms 6 May 2022 766th c0d3-4-F00d 🇩🇪 876 89 364ms 5 May 2022 766th fkantelberg 876 89 374ms 15 Jul 2023 766th TRexOnGit 876 89 364ms 16 Feb 2024 769th inventshah 876 97 61ms 6 May 2022 769th roupiq 🇵🇱 876 97 60ms 22 Nov 2023 769th emgordon154 876 97 59ms 8 Feb 2026 772nd MeWhenI 🇻🇦 876 110 286ms 9 Feb 2023 772nd edsrzf 🇳🇿 876 110 267ms 28 Nov 2024 772nd targrik 876 110 282ms 30 Jun 2025 775th AlephSquirrel 875 80 12ms 20 Apr 2023 775th ashtraypettingzoo 🇺🇸 875 80 14ms 1 Apr 2024 777th kg583 🇺🇸 875 105 13ms 17 days ago 777th Steffan153 🇫🇮 875 105 13ms 12 days ago 779th DialFrost 🇸🇬 874 69 99ms 15 Jul 2024 780th Irratix 🇳🇱 874 72 2ms 4 May 2022 780th m-tkach 🇺🇦 874 72 2ms 4 May 2022 780th jared-hughes 874 72 2ms 6 Jul 2022 780th michael-pruglo 🇺🇦 874 72 2ms 13 Jul 2022 780th Steffan153 🇫🇮 874 72 2ms 3 Jan 2023 780th MeWhenI 🇻🇦 874 72 2ms 7 May 2023 780th ListeriaM 874 72 2ms 22 Aug 2023 780th JohandeRuiter 🇳🇱 874 72 3ms 14 Sep 2024 780th larcherMTT 874 72 2ms 5 Oct 2024 780th snyderek 🇺🇸 874 72 2ms 19 Feb 2025 780th 5quiwyrm 874 72 2ms 29 Jun 2025 780th TeodorDyakov 🇧🇬 874 72 3ms 8 Jul 2025 780th xiaoyiming123 874 72 2ms 12 Jul 2025 793rd Steffan153 🇫🇮 874 83 465ms 9 Apr 2023 793rd ovs-code 🇩🇪 874 83 57ms 1 Jul 2024 795th Shanethegamer 🇺🇸 874 98 110ms 15 Apr 2025 795th GolfingSuccess 🇬🇷 874 98 102ms 28 Nov 2025 795th DialFrost 🇸🇬 874 98 117ms 1 Dec 2025 798th DialFrost 🇸🇬 873 64 7ms 10 Jul 2024 799th Andriamanitra 🇫🇮 872 54 42ms 21 Jul 2022 799th jared-hughes 872 54 39ms 12 Sep 2022 First Prev 721–800 of 3,650 Next Last