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 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 721st CaedenHarper 🇨🇦 869 54 1,364ms 27 Sep 2025 721st sean-niemann 🇺🇸 869 54 1,464ms 27 Sep 2025 721st albanian-laundromat 869 54 1,533ms 14 Nov 2025 721st xsot 🇸🇬 869 54 1,352ms 15 Nov 2025 725th error256 869 80 30ms 11 days ago 726th Shanethegamer 🇺🇸 868 97 110ms 15 Apr 2025 726th GolfingSuccess 🇬🇷 868 97 102ms 28 Nov 2025 726th DialFrost 🇸🇬 868 97 117ms 1 Dec 2025 729th kg583 🇺🇸 868 105 13ms 17 days ago 729th Steffan153 🇫🇮 868 105 13ms 12 days ago 731st nwellnhof 🇩🇪 867 53 7ms 4 May 2022 731st GrayJoKing 🇦🇺 867 53 7ms 6 May 2022 733rd albanian-laundromat 867 73 532ms 16 Dec 2025 734th dieggsy 867 97 28ms 8 Oct 2024 735th ovs-code 🇩🇪 867 133 42ms 8 Jul 2024 736th Shanethegamer 🇺🇸 866 85 38ms 15 May 2023 736th albanian-laundromat 866 85 40ms 25 Aug 2025 738th 123mjb 866 96 366ms 20 Nov 2025 738th noescareno 866 96 366ms 21 Nov 2025 740th emgordon154 866 159 1,606ms 24 Dec 2025 740th DialFrost 🇸🇬 866 159 1,779ms 17 Jan 2026 742nd DialFrost 🇸🇬 865 64 7ms 10 Jul 2024 743rd shellbertt 🇨🇦 864 98 61ms 9 May 2022 743rd iakolzin 864 98 58ms 26 May 2022 743rd Betuaredead 864 98 62ms 5 Jan 2023 743rd oceko 864 98 60ms 19 Feb 2024 743rd cuzdav 864 98 60ms 4 May 2025 743rd timhaj 🇸🇮 864 98 60ms 12 Sep 2025 743rd Yax42 🇫🇷 864 98 61ms 4 Oct 2025 750th emplv 🇱🇻 864 110 294ms 5 May 2022 750th Shanethegamer 🇺🇸 864 110 293ms 21 Nov 2023 750th edsrzf 🇳🇿 864 110 267ms 28 Nov 2024 750th targrik 864 110 282ms 30 Jun 2025 754th nwellnhof 🇩🇪 863 51 40ms 4 May 2022 754th primo-ppcg 🇹🇭 863 51 42ms 6 May 2022 754th janlelis 863 51 38ms 10 May 2022 754th Natanaelel 🇸🇪 863 51 40ms 2 Jun 2022 754th blaztoma 🇱🇹 863 51 38ms 20 days ago 759th deadp4nda 🇩🇪 863 90 374ms 26 Apr 2024 759th 123mjb 863 90 367ms 23 Jun 2025 759th michelebastione 🇮🇹 863 90 400ms 24 Aug 2025 759th razvandmtr 🇷🇴 863 90 395ms 6 Nov 2025 763rd TylerBloom 863 96 123ms 22 Mar 2024 764th Steffan153 🇫🇮 862 82 1,323ms 23 Feb 2023 765th GrayJoKing 🇦🇺 861 56 437ms 15 Jan 2024 765th AlephSquirrel 861 56 396ms 21 Jan 2024 765th CaedenHarper 🇨🇦 861 56 484ms 26 Jan 2026 768th steffan-polygolf 861 73 92ms 23 Feb 2023 768th MWI-polygolf 861 73 92ms 6 Dec 2023 768th HumanoidCPU 861 73 82ms 7 May 2024 771st Yewzir 🇧🇪 861 160 1,887ms 14 Nov 2025 772nd Setvizan 860 62 13ms 12 Jan 2023 772nd GreenBeansAgainstVeganism 860 62 11ms 13 Jan 2023 772nd arctouch-cristiannevianna 860 62 12ms 3 Apr 2023 772nd Corxldyphik 860 62 10ms 11 Apr 2023 772nd Blockyheadman 860 62 10ms 1 Nov 2023 772nd ollyspooner 860 62 11ms 22 Nov 2023 772nd itserasmus 860 62 11ms 25 Jan 2024 772nd Jacob385 860 62 10ms 13 Mar 2024 772nd junkondo-jp 860 62 11ms 30 Jun 2024 772nd ShiraJoseph 🇺🇸 860 62 11ms 1 Mar 2025 772nd tomh1012 860 62 12ms 3 Dec 2025 783rd yzhs 🇩🇪 860 65 20ms 16 Jun 2022 783rd rollershutter 860 65 20ms 9 Sep 2022 783rd bac0id 860 65 21ms 26 Sep 2023 783rd robin-scragg 860 65 23ms 8 Jun 2025 783rd RaBa21 🇭🇺 860 65 26ms 11 Jul 2025 783rd TransformLikeATensor 860 65 19ms 17 Oct 2025 789th Andriamanitra 🇫🇮 860 67 144ms 26 Apr 2023 790th ulucs 859 35 9ms 8 May 2022 790th bstrat 859 35 9ms 6 Jun 2024 790th wh3n3v3r 🇨🇿 859 35 8ms 18 Nov 2024 793rd rucin93 🇵🇱 859 57 150ms 4 Aug 2024 793rd dokutan 859 57 157ms 9 Aug 2024 795th dokutan 859 79 10ms 27 Apr 2024 795th SwordF-Official 🇺🇸 859 79 10ms 1 Feb 2026 797th MeWhenI 🇻🇦 859 81 8ms 23 May 2023 798th MeWhenI 🇻🇦 859 145 1,417ms 28 Mar 2025 799th JRaspass 🇬🇧 858 41 445ms 4 May 2022 799th SirBogman 🇺🇸 858 41 275ms 4 May 2022 First Prev 721–800 of 3,626 Next Last