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 720th sean-niemann 🇺🇸 869 54 1,442ms 27 Sep 2025 720th albanian-laundromat 869 54 959ms 14 Nov 2025 720th xsot 🇸🇬 869 54 1,025ms 15 Nov 2025 724th error256 869 80 30ms 8 days ago 725th Shanethegamer 🇺🇸 868 97 110ms 15 Apr 2025 725th GolfingSuccess 🇬🇷 868 97 102ms 28 Nov 2025 725th DialFrost 🇸🇬 868 97 117ms 1 Dec 2025 728th kg583 🇺🇸 868 105 13ms 14 days ago 728th Steffan153 🇫🇮 868 105 13ms 8 days ago 730th nwellnhof 🇩🇪 867 53 7ms 4 May 2022 730th GrayJoKing 🇦🇺 867 53 8ms 6 May 2022 732nd albanian-laundromat 867 73 532ms 16 Dec 2025 733rd dieggsy 867 97 28ms 8 Oct 2024 734th ovs-code 🇩🇪 867 133 42ms 8 Jul 2024 735th Shanethegamer 🇺🇸 866 85 38ms 15 May 2023 735th albanian-laundromat 866 85 40ms 25 Aug 2025 737th 123mjb 866 96 366ms 20 Nov 2025 737th noescareno 866 96 366ms 21 Nov 2025 739th emgordon154 866 159 1,606ms 24 Dec 2025 739th DialFrost 🇸🇬 866 159 1,779ms 17 Jan 2026 741st DialFrost 🇸🇬 865 64 5ms 10 Jul 2024 742nd shellbertt 🇨🇦 864 98 61ms 9 May 2022 742nd iakolzin 864 98 58ms 26 May 2022 742nd Betuaredead 864 98 62ms 5 Jan 2023 742nd oceko 864 98 60ms 19 Feb 2024 742nd cuzdav 864 98 60ms 4 May 2025 742nd timhaj 🇸🇮 864 98 60ms 12 Sep 2025 742nd Yax42 🇫🇷 864 98 61ms 4 Oct 2025 749th emplv 🇱🇻 864 110 294ms 5 May 2022 749th Shanethegamer 🇺🇸 864 110 293ms 21 Nov 2023 749th edsrzf 🇳🇿 864 110 267ms 28 Nov 2024 749th targrik 864 110 282ms 30 Jun 2025 753rd nwellnhof 🇩🇪 863 51 40ms 4 May 2022 753rd primo-ppcg 🇹🇭 863 51 42ms 6 May 2022 753rd janlelis 863 51 38ms 10 May 2022 753rd Natanaelel 🇸🇪 863 51 40ms 2 Jun 2022 753rd blaztoma 🇱🇹 863 51 38ms 17 days ago 758th deadp4nda 🇩🇪 863 90 374ms 26 Apr 2024 758th 123mjb 863 90 367ms 23 Jun 2025 758th michelebastione 🇮🇹 863 90 400ms 24 Aug 2025 758th razvandmtr 🇷🇴 863 90 395ms 6 Nov 2025 762nd TylerBloom 863 96 123ms 22 Mar 2024 763rd Steffan153 🇫🇮 862 82 1,323ms 23 Feb 2023 764th GrayJoKing 🇦🇺 861 56 437ms 15 Jan 2024 764th AlephSquirrel 861 56 396ms 21 Jan 2024 764th CaedenHarper 🇨🇦 861 56 484ms 26 Jan 2026 767th steffan-polygolf 861 73 92ms 23 Feb 2023 767th MWI-polygolf 861 73 92ms 6 Dec 2023 767th HumanoidCPU 861 73 82ms 7 May 2024 770th Yewzir 🇧🇪 861 160 1,887ms 14 Nov 2025 771st Setvizan 860 62 13ms 12 Jan 2023 771st GreenBeansAgainstVeganism 860 62 11ms 13 Jan 2023 771st arctouch-cristiannevianna 860 62 12ms 3 Apr 2023 771st Corxldyphik 860 62 10ms 11 Apr 2023 771st Blockyheadman 860 62 11ms 1 Nov 2023 771st ollyspooner 860 62 11ms 22 Nov 2023 771st itserasmus 860 62 12ms 25 Jan 2024 771st Jacob385 860 62 10ms 13 Mar 2024 771st junkondo-jp 860 62 12ms 30 Jun 2024 771st ShiraJoseph 🇺🇸 860 62 11ms 1 Mar 2025 771st tomh1012 860 62 12ms 3 Dec 2025 782nd yzhs 🇩🇪 860 65 20ms 16 Jun 2022 782nd rollershutter 860 65 20ms 9 Sep 2022 782nd bac0id 860 65 21ms 26 Sep 2023 782nd robin-scragg 860 65 23ms 8 Jun 2025 782nd RaBa21 🇭🇺 860 65 26ms 11 Jul 2025 782nd TransformLikeATensor 860 65 19ms 17 Oct 2025 788th Andriamanitra 🇫🇮 860 67 144ms 26 Apr 2023 789th ulucs 859 35 9ms 8 May 2022 789th bstrat 859 35 9ms 6 Jun 2024 789th wh3n3v3r 🇨🇿 859 35 8ms 18 Nov 2024 792nd rucin93 🇵🇱 859 57 150ms 4 Aug 2024 792nd dokutan 859 57 157ms 9 Aug 2024 794th dokutan 859 79 10ms 27 Apr 2024 794th SwordF-Official 🇺🇸 859 79 10ms 1 Feb 2026 796th MeWhenI 🇻🇦 859 81 8ms 23 May 2023 797th MeWhenI 🇻🇦 859 145 1,417ms 28 Mar 2025 798th JRaspass 🇬🇧 858 41 388ms 4 May 2022 798th SirBogman 🇺🇸 858 41 227ms 4 May 2022 798th Natanaelel 🇸🇪 858 41 358ms 4 May 2022 First Prev 721–800 of 3,621 Next Last