The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 7 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 481st m-tkach 🇺🇦 822 57 433ms 21 Jan 2024 481st MeWhenI 🇻🇦 822 57 427ms 22 Jul 2024 483rd OllieBoyne 🇬🇧 822 60 34ms 6 Dec 2022 483rd AlexanderFair 822 60 33ms 2 Jul 2023 483rd bzijlema 🇳🇱 822 60 33ms 11 Nov 2023 483rd ahmetdemirag 🇨🇾 822 60 30ms 21 Jul 2024 483rd dokutan 822 60 42ms 21 Aug 2024 483rd BlankSpruce 822 60 11ms 26 Apr 2025 483rd jipsong 🇩🇪 822 60 41ms 13 Jun 2025 483rd webmiche 822 60 12ms 28 Nov 2025 483rd CommandLeo 🇮🇹 822 60 33ms 7 Jan 2026 483rd 051 🇸🇬 822 60 34ms 8 Jan 2026 493rd sisyphus-ppcg 🇦🇺 821 44 36ms 22 Nov 2022 494th Shanethegamer 🇺🇸 821 79 114ms 22 Nov 2022 495th Shanethegamer 🇺🇸 821 105 129ms 22 Nov 2022 495th mousetail 🇳🇱 821 105 126ms 12 Jan 2024 495th prestosilver 🇺🇸 821 105 128ms 31 Dec 2025 498th GrayJoKing 🇦🇺 820 49 5ms 21 Nov 2022 498th DialFrost 🇸🇬 820 49 6ms 24 May 2025 500th DialFrost 🇸🇬 820 79 175ms 8 Aug 2024 500th Natanaelel 🇸🇪 820 79 168ms 31 May 2025 502nd snoozingnewt 🇨🇦 819 60 87ms 8 Feb 2026 503rd Shanethegamer 🇺🇸 819 116 283ms 20 Nov 2022 503rd KasperKivimaeki 🇫🇮 819 116 283ms 3 Oct 2025 505th MeWhenI 🇻🇦 819 171 1,421ms 30 Mar 2025 506th clockworknazo 817 76 2ms 23 Nov 2022 507th ovs-code 🇩🇪 816 33 312ms 30 Dec 2023 508th Shanethegamer 🇺🇸 816 47 1,287ms 21 Nov 2022 509th RYNO8 816 71 2ms 4 Sep 2023 510th MeWhenI 🇻🇦 815 81 125ms 23 Nov 2022 511th DialFrost 🇸🇬 815 102 114ms 2 Dec 2025 511th snoozingnewt 🇨🇦 815 102 96ms 5 Dec 2025 513th GrayJoKing 🇦🇺 814 48 140ms 13 Aug 2024 513th emplv 🇱🇻 814 48 155ms 1 Nov 2024 515th prestosilver 🇺🇸 814 171 1,687ms 31 Dec 2025 516th janbehrens 🇩🇪 813 46 118ms 20 Nov 2022 517th bac0id 813 94 59ms 23 Feb 2024 518th edsrzf 🇳🇿 813 106 136ms 16 Nov 2024 519th CaedenHarper 🇨🇦 812 54 1,412ms 6 Sep 2025 520th thehylian 809 61 33ms 11 Jan 2023 520th galloj 🇨🇿 809 61 36ms 4 Mar 2023 520th commandz0 🇺🇸 809 61 30ms 17 Nov 2023 520th mathisfun271 809 61 33ms 13 Feb 2024 520th BREMAUCY 🇫🇷 809 61 33ms 7 Mar 2024 520th stertooy 🇧🇪 809 61 31ms 10 Jun 2024 520th tri1212 🇻🇳 809 61 42ms 30 Jun 2024 520th Alex-x90 🇺🇸 809 61 11ms 20 Nov 2024 520th solisolu 809 61 30ms 2 Dec 2025 529th SirBogman 🇺🇸 809 179 12ms 22 Nov 2022 530th Lydxn 🇨🇦 808 40 8ms 24 Jun 2023 531st GrayJoKing 🇦🇺 808 58 393ms 15 Jan 2024 531st SirBogman 🇺🇸 808 58 402ms 15 Jan 2024 531st AlephSquirrel 808 58 384ms 16 Jan 2024 534th stefangimmillaro 807 82 2,512ms 7 Nov 2024 535th snyderek 🇺🇸 806 77 2ms 19 Jan 2025 536th marshallward 🇺🇸 805 82 39ms 20 Jun 2023 537th luuumine 🇫🇷 805 107 126ms 17 Nov 2025 538th CaedenHarper 🇨🇦 805 118 299ms 4 Nov 2025 539th janlelis 803 45 44ms 8 Dec 2023 539th DialFrost 🇸🇬 803 45 42ms 2 Aug 2024 539th snoozingnewt 🇨🇦 803 45 45ms 10 Oct 2025 539th emgordon154 803 45 40ms 17 Nov 2025 543rd Shanethegamer 🇺🇸 803 50 1ms 19 Nov 2022 543rd MeWhenI 🇻🇦 803 50 6ms 29 May 2023 545th SirBogman 🇺🇸 800 25 77ms 22 Nov 2022 546th bac0id 800 94 398ms 30 Jun 2024 547th emgordon154 799 48 1,329ms 18 Nov 2024 548th MeWhenI 🇻🇦 799 69 140ms 24 Nov 2022 549th MeWhenI 🇻🇦 798 108 135ms 22 Jul 2024 550th blaztoma 🇱🇹 798 119 288ms 16 Aug 2025 551st Steffan153 🇫🇮 797 49 169ms 11 Feb 2026 552nd Shanethegamer 🇺🇸 797 62 10ms 19 Nov 2022 552nd jared-hughes 797 62 11ms 16 Mar 2023 552nd raphaelimahorn 797 62 10ms 24 Mar 2023 552nd Maznek 797 62 11ms 28 Jun 2023 552nd unfinishedprogram 797 62 11ms 5 Jul 2023 557th Shanethegamer 🇺🇸 797 83 2,692ms 28 Oct 2024 558th DialFrost 🇸🇬 796 47 13ms 25 Sep 2024 559th rak1507 🇬🇧 796 62 31ms 22 Nov 2022 559th fourth-bit 796 62 35ms 7 Dec 2022 First Prev 481–560 of 1,663 Next Last