The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 8 days. Why not try and solve them ahead of time?
Tower of Hanoi 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 CaedenHarper 🇨🇦 662 157 1,890ms 30 Nov 2025 802nd GolfingSuccess 🇬🇷 661 49 3ms 4 Nov 2025 803rd bitsandbeyond 🇳🇱 661 119 121ms 31 Oct 2025 804th LostSyntax21 🇬🇧 660 75 18ms 30 Nov 2025 804th firegene 🇮🇪 660 75 11ms 20 Feb 2026 806th MeWhenI 🇻🇦 660 95 83ms 23 Nov 2025 807th Shanethegamer 🇺🇸 659 102 116ms 2 Nov 2025 808th bitsandbeyond 🇳🇱 656 75 148ms 5 Nov 2025 809th Yewzir 🇧🇪 654 116 28ms 30 Nov 2025 810th madex 🇩🇪 653 74 774ms 9 days ago 811th albanian-laundromat 653 91 4ms 24 Nov 2025 812th AutumnWind75 652 119 444ms 10 Dec 2025 813th Ripick 651 76 11ms 14 Nov 2025 813th scpchicken 🇵🇼 651 76 12ms 5 Dec 2025 815th GolfingSuccess 🇬🇷 651 157 1,511ms 7 Dec 2025 816th emgordon154 650 92 7ms 20 days ago 817th madex 🇩🇪 647 129 269ms 9 days ago 818th BREMAUCY 🇫🇷 646 74 474ms 1 Dec 2025 818th JOrE20 646 74 441ms 7 Jan 2026 820th scpchicken 🇵🇼 643 100 10ms 10 days ago 821st mousetail 🇳🇱 642 77 12ms 23 Nov 2025 822nd jameswmccarty 642 96 2,542ms 8 Feb 2026 823rd GolfingSuccess 🇬🇷 639 72 1ms 30 Oct 2025 824th AlephSquirrel 639 105 9ms 30 Nov 2025 825th dokutan 638 163 1,613ms 5 Dec 2025 826th HumanoidCPU 637 111 457ms 29 Nov 2025 827th msbranicky 637 131 303ms 4 Dec 2025 828th Herbert00709 🇵🇱 636 78 5ms 19 days ago 829th HumanoidCPU 636 122 60ms 29 Nov 2025 830th BREMAUCY 🇫🇷 635 97 2,505ms 3 Dec 2025 831st a6166231 🇨🇳 634 70 10ms 12 Feb 2026 832nd Bmrl7 634 78 11ms 20 Dec 2025 833rd D-MOVE 🇵🇭 632 71 42ms 18 days ago 834th prestosilver 🇺🇸 632 97 2ms 3 Dec 2025 835th scpchicken 🇵🇼 632 132 267ms 10 days ago 836th madex 🇩🇪 631 102 10ms 9 days ago 837th aksyristos 631 123 61ms 3 Dec 2025 837th yeminghan2021 631 123 61ms 3 Feb 2026 839th stackofbears 630 62 34ms 22 Dec 2025 840th dokutan 630 95 7ms 26 days ago 841st scpchicken 🇵🇼 629 76 478ms 1 Jan 2026 842nd jameswmccarty 628 77 716ms 8 Feb 2026 843rd msbranicky 626 79 11ms 26 Nov 2025 843rd nemoyatpeace 626 79 16ms 28 Dec 2025 843rd nstearns96 🇬🇧 626 79 11ms 31 Dec 2025 843rd tomh1012 626 79 10ms 21 days ago 843rd Andrey2001 626 79 11ms 13 hours ago 848th HumanoidCPU 626 105 119ms 29 Nov 2025 849th alexsave 625 71 10ms 30 Nov 2025 850th Waffle3z 622 87 2ms 26 Dec 2025 850th Andriamanitra 🇫🇮 622 87 2ms 21 days ago 852nd msbranicky 622 108 8ms 4 Dec 2025 853rd tomh1012 621 77 435ms 21 days ago 854th HumanoidCPU 621 85 91ms 29 Nov 2025 855th tomh1012 620 78 779ms 21 days ago 856th IISResetMe 619 78 343ms 30 Nov 2025 857th MeWhenI 🇻🇦 618 76 5ms 23 Nov 2025 858th HumanoidCPU 616 72 9ms 29 Nov 2025 858th olleicua 🇺🇸 616 72 10ms 8 Dec 2025 860th JOrE20 614 102 43ms 28 Nov 2025 861st MeWhenI 🇻🇦 613 104 1,025ms 23 Nov 2025 862nd HumanoidCPU 612 121 478ms 30 Nov 2025 863rd AlephSquirrel 611 79 304ms 30 Nov 2025 864th kmathis22 610 101 2,374ms 3 days ago 865th madeforlosers 608 73 10ms 6 days ago 866th MeWhenI 🇻🇦 607 100 6ms 24 Nov 2025 867th TheZwierzLF 🇵🇱 606 74 36ms 5 Jan 2026 868th tomh1012 606 103 427ms 12 Feb 2026 869th msbranicky 605 79 457ms 3 Dec 2025 869th madex 🇩🇪 605 79 447ms 9 days ago 869th Andrey2001 605 79 461ms 13 hours ago 872nd albanian-laundromat 605 82 5ms 25 Nov 2025 873rd MeWhenI 🇻🇦 605 111 123ms 24 Nov 2025 874th HumanoidCPU 604 99 7ms 1 Dec 2025 875th Schmitt-Very-Cool 604 127 8ms 6 Dec 2025 876th dokutan 603 104 77ms 23 Jan 2026 877th HumanoidCPU 601 107 10ms 29 Nov 2025 878th CaedenHarper 🇨🇦 600 88 90ms 30 Nov 2025 879th bitsandbeyond 🇳🇱 600 99 3ms 3 Jan 2026 880th Natanaelel 🇸🇪 600 139 288ms 25 Dec 2025 First Prev 801–880 of 1,460 Next Last