The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 8 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 641st SirBogman 🇺🇸 786 96 450ms 16 Jan 2024 642nd DialFrost 🇸🇬 786 166 40ms 7 May 2025 643rd MeWhenI 🇻🇦 785 137 2ms 12 Sep 2022 644th msbranicky 784 112 2ms 10 Oct 2023 645th DialFrost 🇸🇬 784 113 151ms 24 May 2025 646th MichalMarsalek 🇨🇿 784 117 412ms 21 Apr 2022 647th sean-niemann 🇺🇸 783 118 1ms 3 Feb 2024 648th AlephSquirrel 783 130 6ms 21 Oct 2024 649th imperfect-fourth 783 170 264ms 7 days ago 650th DialFrost 🇸🇬 783 241 1,414ms 18 Apr 2025 651st DialFrost 🇸🇬 782 91 2,754ms 25 Oct 2024 652nd Skleni 782 99 402ms 6 Apr 2023 653rd commandz0 🇺🇸 782 113 10ms 3 Nov 2022 653rd jakobkordez 🇸🇮 782 113 10ms 13 Nov 2022 653rd mossprescott 782 113 10ms 16 Jan 2023 653rd SB-945 782 113 10ms 19 Aug 2023 653rd davitf 782 113 10ms 30 Apr 2024 653rd kbeat 🇰🇿 782 113 10ms 18 May 2025 659th edsrzf 🇳🇿 782 155 269ms 20 hours ago 660th albanian-laundromat 782 167 43ms 4 days ago 661st adamnielson42 🇺🇸 780 91 12ms 26 Apr 2023 661st luuumine 🇫🇷 780 91 10ms 12 Nov 2025 663rd Shanethegamer 🇺🇸 780 104 69ms 4 Dec 2024 664th Shanethegamer 🇺🇸 780 161 41ms 13 Feb 2025 665th MeWhenI 🇻🇦 779 43 4ms 1 Mar 2025 666th JRaspass 🇬🇧 778 60 3ms 18 Jan 2023 667th lifthrasiir 🇰🇷 778 97 525ms 2 Dec 2024 668th primo-ppcg 🇹🇭 777 118 373ms 9 Apr 2022 669th primo-ppcg 🇹🇭 777 131 6ms 20 Jan 2023 670th andersk 🇺🇸 777 156 235ms 30 Oct 2022 670th emgordon154 777 156 249ms 14 Mar 2025 672nd denkyuu1 776 70 36ms 18 Feb 2026 673rd call23re 776 112 2ms 12 Jan 2022 674th LHLaurini 🇧🇷 776 119 1ms 17 Jul 2024 674th solisolu 776 119 1ms 25 Nov 2025 676th kmathis22 776 138 486ms 30 Oct 2025 677th rak1507 🇬🇧 775 40 2ms 10 Jan 2022 677th Frowny 775 40 2ms 13 Jan 2022 677th jared-hughes 775 40 42ms 29 Jul 2022 677th razetime 775 40 2ms 22 Aug 2022 681st Shanethegamer 🇺🇸 775 76 402ms 12 Oct 2022 681st stefangimmillaro 775 76 1,333ms 8 Jan 2023 681st MeWhenI 🇻🇦 775 76 1,213ms 10 May 2023 681st error256 775 76 1,384ms 14 Feb 2025 685th aonkeeper4 775 114 9ms 5 Jul 2022 685th frankgraziano 775 114 10ms 8 Jan 2023 685th m42km 775 114 9ms 22 Nov 2023 685th thienudomsrirungruang 775 114 16ms 14 May 2024 685th jtaxen 775 114 10ms 8 Jun 2024 685th CutSandstone 775 114 10ms 8 Jul 2024 691st Steffan153 🇫🇮 775 132 14ms 5 Jul 2024 692nd strout 775 145 148ms 15 Aug 2022 693rd frankgraziano 774 130 7ms 22 Feb 2026 694th juliansiebert 🇩🇪 773 72 350ms 24 Jul 2022 695th albanian-laundromat 773 76 963ms 7 Nov 2025 696th MeWhenI 🇻🇦 773 130 41ms 30 Dec 2025 697th maxpelic 🇺🇸 772 92 12ms 5 Jul 2022 697th astdefu 772 92 9ms 10 Dec 2022 697th two-bad 🇬🇧 772 92 11ms 25 Feb 2024 697th KatieLG 🇬🇧 772 92 13ms 8 Jul 2024 701st Shanethegamer 🇺🇸 772 157 151ms 8 Oct 2022 702nd fuzzylojik-golf 🇺🇸 770 98 453ms 6 Jul 2025 703rd Yewzir 🇧🇪 770 115 195ms 26 Dec 2023 704th primo-ppcg 🇹🇭 769 67 15ms 24 Jan 2022 705th Shanethegamer 🇺🇸 768 99 87ms 12 Dec 2022 706th jmerle 🇳🇱 768 115 10ms 22 Jan 2022 706th PiterAnnema 768 115 17ms 23 Mar 2022 706th AGoyet 768 115 10ms 29 Jun 2022 706th Eilonlif 🇮🇱 768 115 9ms 11 Sep 2022 706th IsmaelGSerrano 768 115 9ms 2 Nov 2022 706th bobbysq 768 115 10ms 22 Jan 2023 706th msbranicky 768 115 10ms 25 Jul 2023 706th ArenaGrenade 768 115 10ms 19 Feb 2024 706th NickTheEASDude 🇺🇸 768 115 9ms 15 May 2024 706th dokutan 768 115 9ms 13 Aug 2024 706th maxgodfrey2004 🇨🇦 768 115 10ms 8 Jan 2025 706th Pyroan 768 115 10ms 21 Feb 2025 706th chartung17 768 115 10ms 24 Mar 2025 719th DialFrost 🇸🇬 765 71 36ms 26 Dec 2024 720th edsrzf 🇳🇿 765 93 2,784ms 1 Sep 2025 First Prev 641–720 of 1,618 Next Last