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?
Roman to Arabic 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 480th akshatj27 🇦🇶 774 62 39ms 5 Mar 2022 480th scpchicken 🇵🇼 774 62 42ms 5 Mar 2022 480th Irratix 🇳🇱 774 62 38ms 22 Mar 2022 480th prplz 🇦🇺 774 62 46ms 8 Jun 2022 480th Natanaelel 🇸🇪 774 62 42ms 16 Feb 2023 486th HETHAT 🇩🇿 773 93 22ms 22 Mar 2021 486th luuumine 🇫🇷 773 93 22ms 17 Oct 2025 488th wiz0u 773 101 483ms 18 Aug 2025 489th CaedenHarper 🇨🇦 771 131 596ms 3 Oct 2025 489th namelessiw 771 131 622ms 8 Oct 2025 491st Steffan153 🇫🇮 769 103 31ms 14 Feb 2024 492nd michaelmoynihan 767 131 441ms 27 Aug 2025 493rd DialFrost 🇸🇬 766 121 9ms 7 Nov 2023 494th Yewzir 🇧🇪 766 139 5ms 9 Jun 2024 495th primo-ppcg 🇹🇭 764 107 209ms 12 Feb 2022 496th MeWhenI 🇻🇦 764 118 503ms 4 Mar 2022 497th dokutan 762 63 42ms 20 Apr 2025 498th CaedenHarper 🇨🇦 760 149 161ms 22 Aug 2025 499th Yewzir 🇧🇪 759 213 1,976ms 14 Nov 2025 500th dcgjb 757 77 651ms 16 May 2024 501st MeWhenI 🇻🇦 757 108 1,070ms 30 Oct 2023 502nd CaedenHarper 🇨🇦 757 119 400ms 18 Aug 2025 503rd Yewzir 🇧🇪 756 100 15ms 9 Jun 2024 504th m-tkach 🇺🇦 755 133 587ms 14 Aug 2023 505th CaedenHarper 🇨🇦 754 83 1,565ms 18 Aug 2025 506th MeWhenI 🇻🇦 754 101 40ms 1 Nov 2023 507th primo-ppcg 🇹🇭 753 130 129ms 14 Feb 2020 508th primo-ppcg 🇹🇭 751 104 426ms 10 Apr 2025 509th Yewzir 🇧🇪 750 123 241ms 9 Jun 2024 509th CaedenHarper 🇨🇦 750 123 254ms 7 Nov 2025 509th plcc0 750 123 253ms 24 days ago 512th btjones0 749 96 22ms 16 Jul 2022 513th SirBogman 🇺🇸 748 49 6ms 16 Nov 2023 514th MarcMush 🇫🇷 748 79 1,225ms 11 Jan 2024 515th Steffan153 🇫🇮 747 59 169ms 25 Jan 2023 515th sean-niemann 🇺🇸 747 59 170ms 27 Apr 2024 517th janbehrens 🇩🇪 747 78 1,122ms 3 Dec 2023 518th dokutan 747 103 24ms 1 Jul 2024 519th CaedenHarper 🇨🇦 744 39 103ms 26 Oct 2025 520th primo-ppcg 🇹🇭 744 121 368ms 17 Apr 2022 521st xsot 🇸🇬 743 87 522ms 25 Jan 2024 521st CaedenHarper 🇨🇦 743 87 465ms 8 Dec 2025 523rd ovs-code 🇩🇪 742 46 35ms 6 Feb 2024 524th cywong-amino 🇭🇰 742 102 42ms 1 Jul 2020 524th dokutan 742 102 13ms 20 Apr 2025 526th emgordon154 741 97 20ms 24 Sep 2024 527th 4hg 🇺🇸 739 65 41ms 25 Jan 2023 528th inventshah 739 85 7ms 15 Nov 2022 529th janbehrens 🇩🇪 739 122 500ms 18 May 2023 529th plcc0 739 122 460ms 24 days ago 531st MeWhenI 🇻🇦 739 136 61ms 10 Apr 2024 532nd Shanethegamer 🇺🇸 738 79 648ms 31 Oct 2023 533rd sean-niemann 🇺🇸 737 106 455ms 31 Oct 2023 534th kg583 🇺🇸 737 173 87ms 5 days ago 535th janbehrens 🇩🇪 736 106 8ms 2 Jul 2023 535th Shanethegamer 🇺🇸 736 106 8ms 2 Jul 2023 537th jared-hughes 736 245 131ms 6 Jul 2024 538th inventshah 735 88 504ms 22 Jan 2024 538th ovs-code 🇩🇪 735 88 558ms 27 Jan 2024 538th m-tkach 🇺🇦 735 88 527ms 31 Jan 2024 538th albanian-laundromat 735 88 519ms 9 Aug 2025 542nd HPWiz 🇳🇿 734 98 20ms 5 Sep 2021 542nd jakobkordez 🇸🇮 734 98 19ms 31 Oct 2022 542nd Rubiksmath 734 98 20ms 5 Sep 2023 542nd ovs-code 🇩🇪 734 98 41ms 27 Jan 2024 542nd elgan65536 🇺🇸 734 98 23ms 31 Mar 2024 542nd 4atj 734 98 19ms 30 Jun 2025 548th ETHproductions 🇺🇸 734 103 14ms 7 May 2018 548th thisishowmymindworks 🇳🇴 734 103 21ms 6 Aug 2020 548th Maznek 734 103 16ms 28 Jun 2023 551st lynn 733 159 37ms 21 Jul 2023 552nd MeWhenI 🇻🇦 732 112 12ms 23 May 2023 553rd SirBogman 🇺🇸 727 66 40ms 20 Mar 2022 554th sisyphus-ppcg 🇦🇺 727 89 534ms 16 Jan 2024 554th MeWhenI 🇻🇦 727 89 485ms 24 May 2024 556th CaedenHarper 🇨🇦 727 104 14ms 17 Aug 2025 557th Lydxn 🇨🇦 727 139 485ms 30 Jun 2021 557th dokutan 727 139 571ms 13 Nov 2025 559th xnor-gate 726 99 41ms 18 Sep 2021 559th wh3n3v3r 🇨🇿 726 99 19ms 8 Nov 2024 First Prev 481–560 of 1,509 Next Last