The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 5 days. Why not try and solve them ahead of time?
Inventory Sequence 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 637th willschremmer 759 65 21ms 11 May 2024 637th CLOStrophobic 🇮🇹 759 65 11ms 31 Jan 2025 637th JunkIce 759 65 15ms 13 Feb 2025 637th TheZwierzLF 🇵🇱 759 65 34ms 27 May 2025 637th rucin93 🇵🇱 759 65 22ms 31 May 2025 637th Bmrl7 759 65 15ms 23 Dec 2025 647th edsrzf 🇳🇿 759 124 28ms 2 days ago 648th MeWhenI 🇻🇦 758 53 1ms 10 Feb 2023 649th RedzGoose 🇦🇺 756 62 414ms 10 Sep 2024 650th albanian-laundromat 755 115 25ms 14 days ago 651st KatieLG 🇬🇧 753 48 39ms 1 Sep 2024 652nd yeminghan2021 750 102 63ms 1 Feb 2025 653rd bac0id 749 66 12ms 30 Jun 2024 653rd CaedenHarper 🇨🇦 749 66 13ms 23 Aug 2025 653rd snoozingnewt 🇨🇦 749 66 11ms 13 Oct 2025 653rd iczelia 🇩🇪 749 66 15ms 23 Oct 2025 657th Natanaelel 🇸🇪 748 36 122ms 20 Feb 2023 658th jared-hughes 748 50 9ms 22 Nov 2022 659th mdnestor 748 66 41ms 23 Dec 2022 659th jared-hughes 748 66 11ms 16 Mar 2023 659th fgrosshans 🇫🇷 748 66 44ms 14 Jul 2024 659th codingisgreatbutiamnot 748 66 40ms 9 Aug 2024 659th hellwue 748 66 44ms 4 Sep 2024 659th iczelia 🇩🇪 748 66 32ms 23 Oct 2025 659th Europe2048 748 66 15ms 12 days ago 666th msbranicky 747 74 3ms 10 Oct 2023 667th blaztoma 🇱🇹 744 54 2ms 2 Sep 2025 667th albanian-laundromat 744 54 2ms 21 Dec 2025 669th Babafaba 742 78 2ms 14 Oct 2025 670th MichalMarsalek 🇨🇿 742 89 410ms 20 Nov 2022 671st snoozingnewt 🇨🇦 739 84 2ms 13 Oct 2025 672nd anter69 🇭🇺 738 49 38ms 9 Feb 2023 673rd rucin93 🇵🇱 737 53 137ms 6 Dec 2024 674th vishwathg 736 67 29ms 4 Feb 2023 674th Yewzir 🇧🇪 736 67 16ms 7 Feb 2024 674th wh3n3v3r 🇨🇿 736 67 18ms 14 Nov 2024 674th jamesthekee 736 67 14ms 25 Jan 2025 678th blaztoma 🇱🇹 735 90 2,698ms 2 Sep 2025 679th klixel 🇨🇦 735 104 457ms 17 Oct 2024 680th MeWhenI 🇻🇦 735 197 13ms 1 Aug 2023 681st JRaspass 🇬🇧 734 44 3ms 20 Nov 2022 682nd frankgraziano 733 51 136ms 27 Feb 2025 683rd namelessiw 732 64 409ms 5 Mar 2024 683rd rucin93 🇵🇱 732 64 460ms 31 May 2025 685th kg583 🇺🇸 731 85 18ms 5 Dec 2025 686th Shanethegamer 🇺🇸 730 55 5ms 22 Nov 2022 686th snoozingnewt 🇨🇦 730 55 2ms 13 Oct 2025 688th msbranicky 730 103 367ms 10 Jan 2024 689th MeWhenI 🇻🇦 730 129 29ms 5 Jun 2023 690th blaztoma 🇱🇹 728 89 108ms 17 Aug 2025 691st emgordon154 727 91 2,683ms 28 Oct 2024 692nd MichalMarsalek 🇨🇿 726 68 23ms 20 Nov 2022 692nd jmerle 🇳🇱 726 68 22ms 11 Jul 2023 692nd nemoyatpeace 726 68 15ms 15 Jan 2026 695th ovs-code 🇩🇪 726 95 30ms 2 Jul 2024 696th TFeld00 🇩🇰 723 50 40ms 3 Sep 2024 697th KatieLG 🇬🇧 723 53 1,465ms 3 Jan 2024 698th Shanethegamer 🇺🇸 722 86 8ms 23 Nov 2022 698th blaztoma 🇱🇹 722 86 2ms 2 Sep 2025 700th Stockoh 🇫🇷 721 65 455ms 24 Jun 2024 700th JunkIce 721 65 427ms 13 Feb 2025 700th TheZwierzLF 🇵🇱 721 65 441ms 11 Dec 2025 703rd MeWhenI 🇻🇦 721 92 1,025ms 21 May 2023 704th annaproxy 721 106 59ms 23 Jan 2023 704th Babafaba 721 106 2,511ms 14 Oct 2025 706th angel-p57 🇯🇵 721 236 5ms 7 Dec 2023 707th Shanethegamer 🇺🇸 720 57 245ms 19 Nov 2022 708th Chinay-Domitrix 🇺🇸 719 92 2,532ms 8 days ago 709th Shanethegamer 🇺🇸 716 77 145ms 22 Nov 2022 710th FortuiteMan 🇫🇷 716 102 31ms 6 Jan 2026 711th ovs-code 🇩🇪 715 65 74ms 19 Sep 2023 712th andre-lameirinhas 🇵🇹 715 69 15ms 23 Feb 2023 712th jtaxen 715 69 15ms 30 Mar 2024 712th FranklinJiaChen 715 69 39ms 5 Aug 2024 715th Irratix 🇳🇱 715 81 2ms 11 Dec 2022 716th snoozingnewt 🇨🇦 714 133 284ms 13 Oct 2025 717th kg583 🇺🇸 712 73 23ms 27 Dec 2024 717th CLOStrophobic 🇮🇹 712 73 25ms 18 Feb 2025 719th blaztoma 🇱🇹 712 121 121ms 2 Sep 2025 720th edsrzf 🇳🇿 711 81 26ms 17 Jan 2025 First Prev 641–720 of 1,664 Next Last