The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 2 days. Why not try and solve them ahead of time?
Lucky Numbers 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 641st alexsave 608 94 28ms 15 Nov 2025 642nd MeWhenI 🇻🇦 607 116 555ms 1 Nov 2023 643rd janbehrens 🇩🇪 606 185 294ms 22 Jun 2023 644th MeWhenI 🇻🇦 605 121 400ms 9 May 2024 645th Shanethegamer 🇺🇸 604 102 115ms 8 Jun 2022 646th CheeseCake628 🇳🇴 603 80 365ms 17 Jan 2024 647th elgan65536 🇺🇸 603 151 163ms 9 Mar 2024 648th j-Ewan 603 186 299ms 11 Mar 2022 649th MeWhenI 🇻🇦 603 318 1,016ms 29 Aug 2023 650th OllieBoyne 🇬🇧 602 84 88ms 25 May 2022 650th fredrik-bakke 🇳🇴 602 84 54ms 5 Oct 2022 652nd Larento 602 95 33ms 10 Oct 2023 653rd neihousaigaai 600 187 291ms 22 Oct 2024 654th stefangimmillaro 599 113 113ms 4 Nov 2022 655th rucin93 🇵🇱 597 85 206ms 13 Aug 2024 656th 09cf 597 114 15ms 21 Sep 2023 657th edsrzf 🇳🇿 596 105 163ms 29 May 2025 658th tatzyr 🇯🇵 595 75 89ms 11 Mar 2025 659th MichalMarsalek 🇨🇿 595 85 69ms 1 Mar 2022 659th rak1507 🇬🇧 595 85 11ms 21 May 2022 659th LeeCamp 595 85 95ms 11 Jan 2023 659th Terobero 595 85 11ms 23 Aug 2024 659th Deedogg 595 85 41ms 30 Oct 2025 664th strout 595 106 528ms 17 Aug 2022 665th Re-Adventures 🇮🇳 591 154 188ms 20 Jul 2023 666th CornerMercury 🇬🇧 590 190 311ms 11 Feb 2026 667th junkondo-jp 589 97 34ms 25 Jun 2024 667th CaedenHarper 🇨🇦 589 97 21ms 27 Jan 2025 669th AkashTandon167 588 86 11ms 18 Mar 2022 669th yokasuretsu 588 86 11ms 7 Jan 2025 671st DaCuteRaccoon 588 326 824ms 1 Dec 2022 672nd albanian-laundromat 587 93 2,672ms 16 Sep 2025 673rd MeWhenI 🇻🇦 587 110 15ms 21 Jul 2023 674th albanian-laundromat 587 137 89ms 4 Sep 2025 675th keelimeguy 🇺🇸 584 192 303ms 28 Apr 2025 676th trinityy-7 583 98 14ms 17 Mar 2024 676th snoozingnewt 🇨🇦 583 98 20ms 29 Sep 2025 676th iczelia 🇩🇪 583 98 22ms 17 Oct 2025 679th msbranicky 581 87 19ms 23 Jul 2023 680th kimbo 🇺🇸 581 193 284ms 13 Jan 2023 681st MeWhenI 🇻🇦 579 87 1,851ms 28 Jan 2023 682nd MeWhenI 🇻🇦 579 155 44ms 4 Sep 2024 683rd CaedenHarper 🇨🇦 579 331 338ms 27 Jan 2025 684th Shanethegamer 🇺🇸 578 117 35ms 12 Sep 2022 685th CaedenHarper 🇨🇦 578 194 298ms 2 Dec 2025 686th albanian-laundromat 577 332 3,096ms 8 Dec 2025 687th 5cw 🇺🇸 575 48 7ms 10 Apr 2023 688th guilhem-roy 🇫🇷 575 88 96ms 1 Mar 2022 688th michelebastione 🇮🇹 575 88 85ms 2 Mar 2022 690th 77Tigers 573 110 319ms 29 May 2024 690th iczelia 🇩🇪 573 110 274ms 17 Oct 2025 692nd NickTheEASDude 🇺🇸 573 121 19ms 1 May 2024 693rd emgordon154 572 100 38ms 9 Aug 2024 693rd advl 572 100 102ms 14 Feb 2025 695th Lv0Sys 🇵🇱 572 196 282ms 27 Feb 2026 696th emgordon154 569 160 224ms 5 Mar 2025 697th Troon 568 89 40ms 29 Sep 2022 697th b10011 🇫🇮 568 89 38ms 8 Jan 2023 697th AbhilashaTandon 568 89 12ms 24 Sep 2023 697th eddvrs 568 89 12ms 20 Dec 2023 701st prestosilver 🇺🇸 567 117 184ms 11 days ago 702nd a6166231 🇨🇳 566 101 12ms 5 Jun 2025 703rd MeWhenI 🇻🇦 566 149 43ms 6 Jun 2023 704th fantaize 566 161 188ms 19 days ago 705th KatieLG 🇬🇧 566 198 372ms 22 Jan 2023 706th KatieLG 🇬🇧 565 109 207ms 22 Jan 2023 707th Shanethegamer 🇺🇸 564 150 96ms 4 Oct 2024 708th rak1507 🇬🇧 563 49 2ms 2 Mar 2022 709th KatieLG 🇬🇧 563 142 519ms 13 Nov 2022 710th jfallon1997 562 90 32ms 7 Sep 2022 710th xDragoxboi 562 90 12ms 30 Jun 2025 710th jacekwladzinski 562 90 11ms 5 Oct 2025 713th janbehrens 🇩🇪 561 99 123ms 2 Jul 2023 714th DaCuteRaccoon 561 102 23ms 30 Nov 2022 714th dylanarmstrong 561 102 14ms 21 Jan 2024 714th acollett89 561 102 29ms 18 Jul 2025 717th heanyang1 561 200 287ms 29 May 2025 718th snoozingnewt 🇨🇦 560 110 309ms 17 Feb 2026 719th HumanoidCPU 558 80 40ms 6 Nov 2024 719th TheZwierzLF 🇵🇱 558 80 1,933ms 25 Dec 2025 First Prev 641–720 of 1,576 Next Last