The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 3 days. 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 81st Lydxn 🇨🇦 945 51 761ms 17 Jan 2024 82nd ovs-code 🇩🇪 945 61 244ms 5 Aug 2024 83rd JayXon 🇺🇸 944 88 390ms 24 Sep 2025 83rd Lydxn 🇨🇦 944 88 409ms 12 Dec 2025 85th Lydxn 🇨🇦 943 59 10ms 6 May 2022 86th JayXon 🇺🇸 942 88 139ms 17 Oct 2022 86th acotis 942 88 134ms 9 Jun 2025 86th kumavale 942 88 129ms 7 Oct 2025 89th 2bular 939 32 27ms 17 Oct 2024 90th primo-ppcg 🇹🇭 938 49 6ms 5 May 2022 90th Lydxn 🇨🇦 938 49 7ms 8 May 2022 92nd Irratix 🇳🇱 936 83 388ms 4 May 2022 92nd nwellnhof 🇩🇪 936 83 383ms 4 May 2022 92nd ScottHamper 936 83 380ms 5 May 2022 92nd Romain-1 🇫🇷 936 83 381ms 1 Jun 2022 92nd Gaddy 🇫🇷 936 83 398ms 1 Jun 2022 92nd 5quiwyrm 936 83 379ms 4 Sep 2022 92nd Betuaredead 936 83 391ms 5 Jan 2023 92nd Yewzir 🇧🇪 936 83 365ms 12 Feb 2023 92nd btnlq 936 83 388ms 9 Mar 2023 92nd Adix-null 🇱🇹 936 83 397ms 17 May 2023 92nd Matgc04 936 83 373ms 19 May 2023 92nd AdrienHache 🇫🇷 936 83 420ms 8 Jun 2023 92nd gblikas 936 83 412ms 23 Jul 2023 92nd KrausRaus 🇺🇸 936 83 392ms 31 Jul 2023 92nd namelessiw 936 83 396ms 9 Apr 2025 92nd dokutan 936 83 391ms 9 Apr 2025 92nd m-tkach 🇺🇦 936 83 411ms 10 Apr 2025 92nd DialFrost 🇸🇬 936 83 401ms 10 Apr 2025 92nd kylejcwu 936 83 374ms 19 Apr 2025 92nd Tyrant7 936 83 409ms 19 Apr 2025 92nd Yax42 🇫🇷 936 83 442ms 19 Apr 2025 92nd MeWhenI 🇻🇦 936 83 378ms 19 Jun 2025 92nd sean-niemann 🇺🇸 936 83 390ms 20 Jun 2025 92nd stefangimmillaro 936 83 391ms 20 Jun 2025 92nd tomh1012 936 83 418ms 28 Aug 2025 92nd fuzzylojik-golf 🇺🇸 936 83 389ms 8 Sep 2025 92nd CaedenHarper 🇨🇦 936 83 377ms 17 Oct 2025 92nd Flix7dev 🇧🇪 936 83 344ms 21 Oct 2025 92nd arcpolaris 936 83 421ms 13 Jan 2026 92nd amazingalek 🇳🇴 936 83 403ms 21 Jan 2026 122nd saito-ta 🇯🇵 935 49 65ms 13 May 2022 122nd Lydxn 🇨🇦 935 49 66ms 28 May 2022 124th inventshah 935 57 15ms 4 May 2022 124th itsh01 935 57 11ms 17 May 2022 124th Natanaelel 🇸🇪 935 57 12ms 16 Jun 2022 124th Attero 🇸🇪 935 57 12ms 3 Aug 2022 124th SirFireball3521 935 57 11ms 26 Jan 2023 124th Kacarott 🇦🇺 935 57 12ms 24 Mar 2023 124th nathanadams 🇳🇿 935 57 12ms 24 Apr 2023 124th hacker112 🇸🇪 935 57 12ms 20 Jun 2024 124th thisishowmymindworks 🇳🇴 935 57 16ms 28 Jun 2024 124th Salutations45 935 57 13ms 18 Nov 2024 124th daniel-cardone 935 57 12ms 3 Jul 2025 124th CaedenHarper 🇨🇦 935 57 11ms 28 Sep 2025 124th BrunoVisnadi 🇧🇷 935 57 11ms 21 Oct 2025 124th Laellekoenig 935 57 12ms 22 Oct 2025 124th madex 🇩🇪 935 57 11ms 13 days ago 139th DialFrost 🇸🇬 934 89 513ms 24 Sep 2025 139th ovs-code 🇩🇪 934 89 474ms 24 Sep 2025 139th dokutan 934 89 372ms 24 Sep 2025 139th sean-niemann 🇺🇸 934 89 397ms 24 Sep 2025 139th Shanethegamer 🇺🇸 934 89 477ms 25 Sep 2025 139th nwellnhof 🇩🇪 934 89 454ms 25 Sep 2025 139th m-tkach 🇺🇦 934 89 386ms 25 Sep 2025 139th namelessiw 934 89 390ms 2 Oct 2025 139th Yewzir 🇧🇪 934 89 349ms 2 Oct 2025 139th Yax42 🇫🇷 934 89 496ms 4 Oct 2025 139th stefangimmillaro 934 89 489ms 6 Oct 2025 139th CaedenHarper 🇨🇦 934 89 467ms 9 Oct 2025 139th Jacob385 934 89 491ms 27 Oct 2025 139th MeWhenI 🇻🇦 934 89 449ms 7 Nov 2025 139th ethanlally 934 89 380ms 10 Nov 2025 139th snoozingnewt 🇨🇦 934 89 384ms 23 Nov 2025 139th ScottHamper 934 89 467ms 30 Nov 2025 139th KasperKivimaeki 🇫🇮 934 89 444ms 30 Nov 2025 157th primo-ppcg 🇹🇭 933 58 4ms 13 Nov 2022 157th clockworknazo 933 58 5ms 15 Nov 2022 157th Lydxn 🇨🇦 933 58 5ms 7 Feb 2023 157th xsot 🇸🇬 933 58 5ms 28 Jun 2024 First Prev 81–160 of 3,621 Next Last