The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 6 days. Why not try and solve them ahead of time?
ISBN 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 799th emgordon154 746 79 1,321ms 25 Nov 2024 799th Shanethegamer 🇺🇸 746 79 1,255ms 9 Apr 2025 803rd stefangimmillaro 746 102 107ms 19 Oct 2022 804th Shanethegamer 🇺🇸 746 111 106ms 4 Dec 2025 805th MeWhenI 🇻🇦 745 123 369ms 30 Jan 2023 806th djeedjay 🇳🇱 745 124 1ms 16 Sep 2022 807th BlankSpruce 745 149 57ms 16 Jan 2022 808th lacrosse 744 73 35ms 28 Nov 2025 809th dokutan 744 79 994ms 8 Sep 2025 810th primo-ppcg 🇹🇭 744 144 419ms 4 Apr 2022 810th Lydxn 🇨🇦 744 144 435ms 5 Apr 2022 810th rotary-o 🇯🇵 744 144 457ms 5 May 2023 810th Jacob385 744 144 547ms 28 Oct 2025 814th HumanoidCPU 744 179 279ms 3 Mar 2025 815th BREMAUCY 🇫🇷 744 316 13ms 15 Dec 2025 816th MeWhenI 🇻🇦 742 96 130ms 25 Oct 2024 817th RYNO8 742 119 10ms 18 Feb 2022 817th eshilo-draper 742 119 10ms 10 Oct 2022 817th georgehulme 742 119 9ms 12 Oct 2022 817th Omega65536 🇩🇪 742 119 10ms 24 Nov 2022 817th Ripick 742 119 10ms 2 Feb 2023 817th Ythaenagor 742 119 9ms 5 Aug 2024 817th PyryL 🇫🇮 742 119 10ms 20 Aug 2024 817th JunkIce 742 119 9ms 25 Nov 2024 817th Stockoh 🇫🇷 742 119 10ms 13 Feb 2025 817th Alban-Boissard 742 119 10ms 14 Jun 2025 827th emplv 🇱🇻 742 182 25ms 31 Oct 2022 828th madex 🇩🇪 741 96 2,855ms 4 days ago 829th MeWhenI 🇻🇦 741 138 7ms 9 May 2024 830th BambooleanLogic 🇸🇪 740 96 11ms 20 Aug 2022 830th vroup 🇩🇰 740 96 11ms 2 Oct 2022 830th Ultra814 740 96 10ms 17 Aug 2025 833rd dokutan 740 102 465ms 13 Aug 2024 834th weliveinhell 🇭🇹 740 180 300ms 4 Oct 2023 834th emgordon154 740 180 281ms 20 Feb 2025 836th jupj 🇫🇮 739 125 2ms 31 Aug 2022 837th KenanSi 738 42 2ms 24 Feb 2022 837th Natanaelel 🇸🇪 738 42 2ms 21 Jun 2022 837th GolfingSuccess 🇬🇷 738 42 2ms 31 Dec 2022 840th SirBogman 🇺🇸 738 59 32ms 8 Sep 2022 841st billings7 🇬🇧 737 105 428ms 12 Nov 2023 841st MiffOttah 737 105 422ms 28 Nov 2024 843rd fkantelberg 736 120 10ms 18 Jul 2023 843rd Bmrl7 736 120 10ms 29 Feb 2024 843rd elgan65536 🇺🇸 736 120 16ms 1 Apr 2024 843rd robin-scragg 736 120 10ms 25 Jul 2025 847th emgordon154 736 139 9ms 20 Feb 2025 848th JRaspass 🇬🇧 736 181 295ms 23 Sep 2022 849th retrohun 735 151 53ms 30 Dec 2022 849th annaproxy 735 151 60ms 5 Jan 2023 851st Waffle3z 734 74 36ms 12 Jan 2022 851st olleicua 🇺🇸 734 74 37ms 16 Feb 2024 851st emgordon154 734 74 36ms 25 Jun 2024 854th yzhs 🇩🇪 734 153 146ms 25 Jun 2023 855th SirBogman 🇺🇸 734 320 14ms 21 May 2022 856th KatieLG 🇬🇧 733 103 459ms 27 Oct 2024 857th bac0id 733 126 1ms 3 Jul 2024 858th Yewzir 🇧🇪 733 137 35ms 28 Nov 2023 859th dokutan 732 97 11ms 5 Jun 2025 859th iczelia 🇩🇪 732 97 10ms 26 Sep 2025 859th johnkiernander 732 97 11ms 14 Dec 2025 862nd ericlangedijk 🇸🇮 730 106 421ms 19 Mar 2022 863rd Natanaelel 🇸🇪 730 121 9ms 12 Jan 2022 863rd NerdyMcNerd42 730 121 10ms 20 Aug 2022 863rd Kloppermand 🇩🇰 730 121 9ms 3 Oct 2022 863rd ehulinsky 🇺🇸 730 121 16ms 15 May 2023 863rd AbhilashaTandon 730 121 10ms 21 Sep 2023 863rd davecame 730 121 10ms 2 Oct 2023 863rd gussy420 730 121 9ms 23 Oct 2023 863rd tobyLovick 730 121 10ms 13 Dec 2023 871st jared-hughes 730 152 461ms 24 Jun 2022 871st Betuaredead 730 152 460ms 7 Jan 2023 873rd Shanethegamer 🇺🇸 728 138 38ms 6 Sep 2022 874th mlugg 728 203 1,617ms 10 Aug 2024 875th MeWhenI 🇻🇦 726 72 2ms 13 Nov 2022 876th MeWhenI 🇻🇦 726 81 990ms 15 Sep 2025 877th commandz0 🇺🇸 726 104 485ms 1 Sep 2025 878th dokutan 726 153 81ms 8 Nov 2025 879th jared-hughes 725 75 38ms 9 Sep 2022 880th krcs 🇵🇱 725 98 10ms 2 May 2022 First Prev 801–880 of 1,620 Next Last
