The Calendar hole will go live in approximately 4 days. Why not try and solve it 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 Card Number Validation Catalan Numbers Catalan’s Constant Christmas Trees Collatz 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 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 Apéry’s Constant Binary Lambda Calculus Calendar Connect Four Continued Fractions Crossword CSS Colors (Inverse) CSS Grid Ellipse Perimeters Flags Floyd-Steinberg Dithering Gray Code Decoder Gray Code Encoder Hexagonal Spiral Highly Composite Numbers Multitap Input NFA Simulator Numbrix Odd Polyomino Tiling p-adic Expansion Polygon Triangulations QR Encoder Quadratic Formula Semiprime Numbers Smooth Numbers Snake Sphenic Numbers Taxicab Numbers Turtle Tutorial All Languages ><> 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 ALGOL 68 APL Arturo Befunge BQN CJam CoffeeScript Egel Fennel Harbour Hare Haxe Hush Hy iogii Knight Luau Odin Picat Qore Racket Rebol Rexx Scala Squirrel Stax Uiua Umka Vala Vyxal Bytes Chars Scoring Bytes Chars Language All ><> 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 ALGOL 68 APL Arturo Befunge BQN CJam CoffeeScript Egel Fennel Harbour Hare Haxe Hush Hy iogii Knight 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 Card Number Validation Catalan Numbers Catalan’s Constant Christmas Trees Collatz 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 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 Apéry’s Constant Binary Lambda Calculus Calendar Connect Four Continued Fractions Crossword CSS Colors (Inverse) CSS Grid Ellipse Perimeters Flags Floyd-Steinberg Dithering Gray Code Decoder Gray Code Encoder Hexagonal Spiral Highly Composite Numbers Multitap Input NFA Simulator Numbrix Odd Polyomino Tiling p-adic Expansion Polygon Triangulations QR Encoder Quadratic Formula Semiprime Numbers Smooth Numbers Snake Sphenic Numbers Taxicab Numbers Turtle Tutorial # Golfer Points Bytes Time Submitted 707th madex 🇩🇪 877 61 10ms 9 Jul 2024 707th FortuiteMan 🇫🇷 877 61 9ms 10 Oct 2024 707th RobertHoeh 877 61 13ms 5 Apr 2025 707th LvLError 877 61 10ms 29 May 2025 707th miles-evan 877 61 10ms 5 Aug 2025 707th alexsave 877 61 10ms 13 Oct 2025 727th GolfingSuccess 🇬🇷 876 57 819ms 29 Aug 2025 728th MeWhenI 🇻🇦 876 110 278ms 9 Feb 2023 728th edsrzf 🇳🇿 876 110 258ms 28 Nov 2024 728th targrik 876 110 267ms 30 Jun 2025 731st nwellnhof 🇩🇪 875 53 6ms 4 May 2022 731st GrayJoKing 🇦🇺 875 53 7ms 6 May 2022 733rd AlephSquirrel 875 80 12ms 20 Apr 2023 733rd ashtraypettingzoo 🇺🇸 875 80 15ms 1 Apr 2024 735th c0d3-4-F00d 🇩🇪 875 89 370ms 5 May 2022 735th fkantelberg 875 89 340ms 15 Jul 2023 735th TRexOnGit 875 89 378ms 16 Feb 2024 738th inventshah 875 97 58ms 6 May 2022 738th roupiq 🇵🇱 875 97 55ms 22 Nov 2023 740th DialFrost 🇸🇬 874 69 88ms 15 Jul 2024 741st Steffan153 🇫🇮 874 83 446ms 9 Apr 2023 742nd ovs-code 🇩🇪 874 85 15ms 11 Dec 2023 743rd Irratix 🇳🇱 873 72 2ms 4 May 2022 743rd m-tkach 🇺🇦 873 72 2ms 4 May 2022 743rd jared-hughes 873 72 2ms 6 Jul 2022 743rd michael-pruglo 🇺🇦 873 72 2ms 13 Jul 2022 743rd Steffan153 🇫🇮 873 72 2ms 3 Jan 2023 743rd MeWhenI 🇻🇦 873 72 3ms 7 May 2023 743rd ListeriaM 873 72 2ms 22 Aug 2023 743rd JohandeRuiter 🇳🇱 873 72 3ms 14 Sep 2024 743rd larcherMTT 873 72 2ms 5 Oct 2024 743rd snyderek 🇺🇸 873 72 3ms 19 Feb 2025 743rd 5quiwyrm 873 72 2ms 29 Jun 2025 743rd TeodorDyakov 🇧🇬 873 72 3ms 8 Jul 2025 743rd xiaoyiming123 873 72 2ms 12 Jul 2025 756th ovs-code 🇩🇪 873 83 54ms 1 Jul 2024 757th Andriamanitra 🇫🇮 872 54 44ms 21 Jul 2022 757th jared-hughes 872 54 41ms 12 Sep 2022 757th OhmNomNom 872 54 41ms 7 Oct 2022 757th olleicua 🇺🇸 872 54 42ms 21 Jan 2024 757th LostSyntax21 🇬🇧 872 54 40ms 12 Mar 2025 757th AbrahamJLR 🇻🇪 872 54 44ms 4 Jun 2025 757th vishal-mohanty 872 54 40ms 25 Aug 2025 764th DialFrost 🇸🇬 872 64 5ms 10 Jul 2024 765th MeWhenI 🇻🇦 872 85 41ms 27 Jun 2022 765th Shanethegamer 🇺🇸 872 85 38ms 15 May 2023 765th albanian-laundromat 872 85 40ms 25 Aug 2025 768th dieggsy 872 97 28ms 8 Oct 2024 769th ulucs 871 35 9ms 8 May 2022 769th bstrat 871 35 9ms 6 Jun 2024 769th wh3n3v3r 🇨🇿 871 35 8ms 18 Nov 2024 772nd scpchicken 🇵🇼 871 45 365ms 4 May 2022 772nd SirBogman 🇺🇸 871 45 225ms 5 May 2022 774th TFeld00 🇩🇰 871 71 24ms 17 May 2022 774th DialFrost 🇸🇬 871 71 24ms 15 Nov 2022 774th StefanHabel 🇨🇦 871 71 18ms 29 Nov 2022 774th nstearns96 🇬🇧 871 71 18ms 11 Jan 2023 774th hallvabo 🇳🇴 871 71 19ms 7 Feb 2023 774th anter69 🇭🇺 871 71 17ms 21 May 2024 774th rucin93 🇵🇱 871 71 17ms 10 Jul 2024 774th lelbal 871 71 19ms 26 Aug 2025 774th HETHAT 🇩🇿 871 71 23ms 23 Sep 2025 774th 09cf 871 71 17ms 18 Nov 2025 774th blaztoma 🇱🇹 871 71 24ms 25 Nov 2025 774th Languag3 871 71 23ms 22 days ago 786th ovs-code 🇩🇪 871 133 42ms 8 Jul 2024 787th CaedenHarper 🇨🇦 869 60 431ms 28 Sep 2025 788th Steffan153 🇫🇮 869 82 1,287ms 23 Feb 2023 789th 123mjb 869 96 356ms 20 Nov 2025 789th noescareno 869 96 406ms 21 Nov 2025 791st Shanethegamer 🇺🇸 869 98 100ms 15 Apr 2025 791st GolfingSuccess 🇬🇷 869 98 111ms 28 Nov 2025 791st DialFrost 🇸🇬 869 98 94ms 25 days ago 794th Frowny 868 38 40ms 5 May 2022 794th stackofbears 868 38 42ms 14 Mar 2025 796th steffan-polygolf 868 73 87ms 23 Feb 2023 796th MWI-polygolf 868 73 83ms 6 Dec 2023 796th HumanoidCPU 868 73 81ms 7 May 2024 799th nwellnhof 🇩🇪 868 111 271ms 4 May 2022 799th emplv 🇱🇻 868 111 296ms 5 May 2022 First Prev 721–800 of 3,510 Next Last