The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 6 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 387th fuzzylojik-golf 🇺🇸 907 59 11ms 1 Jun 2025 387th acollett89 907 59 12ms 17 Jun 2025 387th iczelia 🇩🇪 907 59 12ms 23 Sep 2025 387th Yax42 🇫🇷 907 59 10ms 20 Jan 2026 387th Protothor 907 59 11ms 4 days ago 406th Steffan153 🇫🇮 907 80 28ms 15 Nov 2022 406th error256 907 80 117ms 8 Apr 2025 408th nipzu 906 48 46ms 8 Sep 2024 409th shinh 906 52 43ms 29 Jun 2022 410th Lydxn 🇨🇦 906 64 181ms 1 Apr 2023 411th krcs 🇵🇱 906 86 381ms 10 May 2022 411th billings7 🇬🇧 906 86 384ms 15 May 2022 411th revlayle 🇺🇸 906 86 379ms 7 Dec 2022 411th Widgitty 906 86 368ms 1 Sep 2023 411th albanian-laundromat 906 86 430ms 30 Sep 2025 416th piano-miles 906 92 411ms 24 Feb 2026 417th Lydxn 🇨🇦 905 70 96ms 7 May 2022 418th MeWhenI 🇻🇦 905 71 148ms 20 Aug 2024 419th m-tkach 🇺🇦 904 72 110ms 16 Oct 2022 419th GrayJoKing 🇦🇺 904 72 113ms 22 Oct 2022 419th emplv 🇱🇻 904 72 111ms 27 Oct 2022 419th sean-niemann 🇺🇸 904 72 172ms 7 Mar 2025 423rd DialFrost 🇸🇬 904 74 17ms 22 Feb 2026 423rd Steffan153 🇫🇮 904 74 17ms 22 Feb 2026 423rd GrayJoKing 🇦🇺 904 74 16ms 22 Feb 2026 423rd GolfingSuccess 🇬🇷 904 74 16ms 24 Feb 2026 423rd snoozingnewt 🇨🇦 904 74 16ms 27 days ago 423rd edsrzf 🇳🇿 904 74 16ms 21 days ago 429th Steffan153 🇫🇮 904 82 42ms 1 Apr 2023 429th sean-niemann 🇺🇸 904 82 42ms 12 Jul 2024 431st stefangimmillaro 904 92 130ms 24 Oct 2023 431st inverseLorentz 🇦🇺 904 92 120ms 27 May 2024 431st sean-niemann 🇺🇸 904 92 129ms 8 Jun 2025 431st ian-h-chamberlain 🇺🇸 904 92 146ms 23 Nov 2025 435th michael-pruglo 🇺🇦 904 94 61ms 5 Jul 2022 435th zygoloid 904 94 60ms 5 Aug 2024 435th AdrienHache 🇫🇷 904 94 60ms 27 Dec 2025 438th Lydxn 🇨🇦 902 69 6ms 12 Sep 2022 438th GrayJoKing 🇦🇺 902 69 7ms 12 Sep 2022 438th btnlq 902 69 7ms 24 Sep 2022 441st albanian-laundromat 901 107 274ms 22 Dec 2025 442nd SirBogman 🇺🇸 900 50 516ms 5 May 2022 442nd nwellnhof 🇩🇪 900 50 504ms 3 Jun 2022 442nd Lydxn 🇨🇦 900 50 431ms 15 Aug 2022 442nd Steffan153 🇫🇮 900 50 485ms 9 Aug 2024 446th Steffan153 🇫🇮 900 67 112ms 18 Dec 2022 446th Lydxn 🇨🇦 900 67 122ms 4 Feb 2023 446th sean-niemann 🇺🇸 900 67 110ms 7 Mar 2025 449th Lydxn 🇨🇦 900 72 353ms 16 Jul 2023 450th Lydxn 🇨🇦 899 48 257ms 5 May 2022 450th p-zubieta 899 48 299ms 6 Mar 2024 452nd GrayJoKing 🇦🇺 899 70 2ms 6 May 2022 452nd saito-ta 🇯🇵 899 70 2ms 21 Dec 2023 452nd ovs-code 🇩🇪 899 70 2ms 17 Feb 2024 452nd trinityy-7 899 70 2ms 7 Aug 2025 452nd KasperKivimaeki 🇫🇮 899 70 6ms 8 Aug 2025 457th GrayJoKing 🇦🇺 899 91 30ms 19 Jan 2023 458th NickTheEASDude 🇺🇸 898 76 6ms 7 May 2024 458th edsrzf 🇳🇿 898 76 6ms 23 Dec 2025 458th Shanethegamer 🇺🇸 898 76 5ms 23 Dec 2025 458th jared-hughes 898 76 5ms 24 Dec 2025 458th Waffle3z 898 76 5ms 26 Dec 2025 458th Blendi-Goose 898 76 5ms 6 Feb 2026 458th kTheLemon 898 76 5ms 24 days ago 465th edsrzf 🇳🇿 898 78 12ms 26 Oct 2024 466th DialFrost 🇸🇬 897 29 154ms 15 Mar 2025 467th Steffan153 🇫🇮 897 59 156ms 10 Aug 2024 467th rucin93 🇵🇱 897 59 144ms 13 Oct 2024 467th sean-niemann 🇺🇸 897 59 147ms 13 Oct 2024 467th lukegustafson 🇺🇸 897 59 140ms 24 Oct 2024 471st Ripick 897 73 122ms 8 May 2023 472nd ovs-code 🇩🇪 897 89 458ms 24 Jul 2024 472nd jipsong 🇩🇪 897 89 450ms 7 Apr 2025 472nd DialFrost 🇸🇬 897 89 485ms 24 Dec 2025 472nd dokutan 897 89 425ms 8 Feb 2026 476th m-tkach 🇺🇦 897 117 25ms 7 May 2022 476th Lydxn 🇨🇦 897 117 26ms 7 May 2022 478th nwellnhof 🇩🇪 896 69 24ms 4 May 2022 478th m-tkach 🇺🇦 896 69 18ms 4 May 2022 478th GolfingSuccess 🇬🇷 896 69 17ms 5 May 2022 First Prev 401–480 of 3,649 Next Last