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?
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 801st betaveros 658 75 15ms 31 Dec 2022 801st Wildst 658 75 17ms 7 Jul 2023 801st mosho-p 658 75 24ms 14 Sep 2023 801st eiburns 658 75 16ms 26 Oct 2023 805th tatzyr 🇯🇵 657 55 39ms 12 Feb 2025 806th MeWhenI 🇻🇦 655 75 91ms 13 Dec 2022 807th RedzGoose 🇦🇺 655 99 120ms 11 Oct 2024 808th MeWhenI 🇻🇦 655 100 4ms 20 Jul 2023 809th CarsonChr 🇺🇸 654 115 403ms 7 Apr 2024 810th ovs-code 🇩🇪 653 90 24ms 21 Nov 2022 811th snoozingnewt 🇨🇦 652 101 89ms 13 Oct 2025 812th msbranicky 651 72 426ms 17 Jan 2024 813th weliveinhell 🇭🇹 650 76 17ms 18 Sep 2023 813th itserasmus 650 76 19ms 9 Apr 2024 813th eranws 650 76 13ms 23 Dec 2024 816th Shanethegamer 🇺🇸 649 75 292ms 22 Apr 2025 817th Edjyzod 649 76 22ms 31 Mar 2023 818th MeWhenI 🇻🇦 647 96 11ms 9 May 2024 819th blaztoma 🇱🇹 647 102 119ms 3 Sep 2025 820th snoozingnewt 🇨🇦 645 68 1,037ms 13 Oct 2025 821st xyangst 642 77 14ms 7 Oct 2024 822nd Squidled 641 77 14ms 3 Jan 2023 822nd mbittner20 641 77 15ms 27 May 2023 822nd HumanoidCPU 641 77 40ms 26 Jun 2024 822nd xyangst 641 77 15ms 7 Oct 2024 826th msbranicky 641 103 125ms 19 Sep 2023 827th MeWhenI 🇻🇦 640 61 133ms 3 Aug 2024 828th snoozingnewt 🇨🇦 640 97 2ms 13 Oct 2025 829th Lydxn 🇨🇦 639 124 405ms 24 Jun 2023 830th Shanethegamer 🇺🇸 638 77 94ms 12 Dec 2022 831st ericlangedijk 🇸🇮 637 118 457ms 23 May 2023 832nd epic-programmer-guy 635 102 188ms 3 Jan 2024 833rd emgordon154 634 91 28ms 30 Dec 2024 834th blaztoma 🇱🇹 632 132 114ms 27 Nov 2025 835th snoozingnewt 🇨🇦 628 105 41ms 13 Oct 2025 836th Techdude01 625 79 15ms 20 Jan 2023 836th rollershutter 625 79 41ms 4 Jul 2023 836th bob-th 625 79 16ms 19 Aug 2023 836th olleicua 🇺🇸 625 79 16ms 19 Jan 2024 836th qwjhvbxi 625 79 15ms 6 Feb 2024 836th StefanHabel 🇨🇦 625 79 18ms 26 days ago 842nd janbehrens 🇩🇪 624 127 434ms 21 Nov 2022 843rd madex 🇩🇪 623 93 2ms 15 Jun 2023 844th blaztoma 🇱🇹 623 151 24ms 3 Sep 2025 845th blaztoma 🇱🇹 620 107 1,025ms 2 Sep 2025 846th Shanethegamer 🇺🇸 619 120 45ms 12 Sep 2024 847th blaztoma 🇱🇹 618 80 11ms 2 Sep 2025 848th blaztoma 🇱🇹 617 76 494ms 2 Sep 2025 849th Vaekor 617 80 17ms 9 Jul 2023 849th fuzzylojik-golf 🇺🇸 617 80 16ms 9 Jun 2025 851st snoozingnewt 🇨🇦 617 105 151ms 13 Oct 2025 852nd msbranicky 616 94 2ms 10 Jan 2024 853rd blaztoma 🇱🇹 616 118 149ms 2 Sep 2025 854th MeWhenI 🇻🇦 615 101 2ms 24 Nov 2022 854th msbranicky 615 101 19ms 4 Aug 2023 856th yzhs 🇩🇪 611 106 139ms 25 Jun 2023 857th emgordon154 610 71 25ms 19 Sep 2024 858th blaztoma 🇱🇹 609 72 1,009ms 3 Sep 2025 858th MeWhenI 🇻🇦 609 72 1,045ms 15 Sep 2025 860th HumanoidCPU 609 77 441ms 26 Jun 2024 861st fkantelberg 609 81 11ms 23 Jul 2023 861st cingulataluke 609 81 15ms 28 Aug 2023 861st CutSandstone 609 81 14ms 4 Jul 2024 864th emgordon154 609 205 4,420ms 18 Jul 2024 865th blaztoma 🇱🇹 608 138 1,296ms 2 Sep 2025 866th blaztoma 🇱🇹 608 229 1,685ms 15 Sep 2025 867th retrohun 603 62 287ms 11 Mar 2023 868th Feniske 🇫🇷 603 68 308ms 6 Nov 2023 869th SwordF-Official 🇺🇸 603 103 11ms 17 Apr 2025 870th blaztoma 🇱🇹 602 60 35ms 2 Sep 2025 871st TaserTheFox 🇺🇸 602 82 17ms 31 Mar 2023 871st alexsave 602 82 23ms 15 Nov 2025 873rd Ripick 600 110 394ms 24 Jun 2024 874th Emutis 🇱🇹 600 132 413ms 4 Sep 2025 875th Shanethegamer 🇺🇸 598 54 3ms 19 Nov 2022 875th snoozingnewt 🇨🇦 598 54 3ms 13 Oct 2025 877th Shanethegamer 🇺🇸 597 104 58ms 22 Dec 2023 877th Yewzir 🇧🇪 597 104 25ms 7 Feb 2024 879th emgordon154 596 35 3ms 19 days ago 880th IISResetMe 595 69 273ms 30 Jun 2023 First Prev 801–880 of 1,669 Next Last