The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 6 days. Why not try and solve them ahead of time?
Tower of Hanoi in all languages in bytes. 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 Bytes Time Submitted 801st firegene 🇮🇪 672 75 11ms 20 Feb 2026 802nd Stockoh 🇫🇷 671 113 28ms 9 Jan 2026 803rd BREMAUCY 🇫🇷 670 74 474ms 1 Dec 2025 803rd JOrE20 670 74 441ms 7 Jan 2026 803rd KrausRaus 🇺🇸 670 74 5ms 23 days ago 806th Yewzir 🇧🇪 670 92 2,466ms 30 Nov 2025 807th elgan65536 🇺🇸 670 98 121ms 7 Feb 2026 808th bitsandbeyond 🇳🇱 669 119 121ms 31 Oct 2025 809th Ripick 663 76 11ms 14 Nov 2025 809th LostSyntax21 🇬🇧 663 76 12ms 30 Nov 2025 809th scpchicken 🇵🇼 663 76 12ms 5 Dec 2025 812th msbranicky 663 93 2,598ms 4 Dec 2025 813th acotis 663 99 112ms 2 Jan 2026 814th CaedenHarper 🇨🇦 662 157 1,890ms 30 Nov 2025 815th GolfingSuccess 🇬🇷 661 49 3ms 4 Nov 2025 816th Shanethegamer 🇺🇸 659 102 116ms 2 Nov 2025 817th bitsandbeyond 🇳🇱 656 75 148ms 5 Nov 2025 818th mousetail 🇳🇱 655 77 12ms 23 Nov 2025 819th Yewzir 🇧🇪 654 116 28ms 30 Nov 2025 820th madex 🇩🇪 653 74 774ms 11 days ago 821st scpchicken 🇵🇼 652 76 478ms 1 Jan 2026 822nd AutumnWind75 652 119 438ms 10 Dec 2025 823rd GolfingSuccess 🇬🇷 651 157 1,502ms 7 Dec 2025 824th emgordon154 650 92 7ms 22 days ago 825th AlephSquirrel 648 105 9ms 30 Nov 2025 826th madex 🇩🇪 647 129 269ms 11 days ago 827th Bmrl7 646 78 11ms 20 Dec 2025 828th tomh1012 644 77 435ms 23 days ago 829th scpchicken 🇵🇼 643 100 10ms 12 days ago 830th HumanoidCPU 643 111 108ms 30 Nov 2025 831st jameswmccarty 642 96 2,542ms 8 Feb 2026 832nd GolfingSuccess 🇬🇷 639 72 1ms 30 Oct 2025 833rd msbranicky 638 79 11ms 26 Nov 2025 833rd nemoyatpeace 638 79 16ms 28 Dec 2025 833rd nstearns96 🇬🇧 638 79 11ms 31 Dec 2025 833rd tomh1012 638 79 10ms 23 days ago 833rd Andrey2001 638 79 11ms 2 days ago 838th dokutan 638 163 1,613ms 5 Dec 2025 839th HumanoidCPU 637 111 457ms 29 Nov 2025 840th msbranicky 637 131 303ms 4 Dec 2025 841st Herbert00709 🇵🇱 636 78 5ms 21 days ago 842nd HumanoidCPU 636 122 57ms 29 Nov 2025 843rd BREMAUCY 🇫🇷 635 97 2,505ms 3 Dec 2025 844th a6166231 🇨🇳 634 70 11ms 12 Feb 2026 845th bitsandbeyond 🇳🇱 634 99 3ms 3 Jan 2026 846th D-MOVE 🇵🇭 632 71 42ms 20 days ago 847th prestosilver 🇺🇸 632 97 2ms 3 Dec 2025 848th scpchicken 🇵🇼 632 132 267ms 12 days ago 849th madex 🇩🇪 631 102 10ms 11 days ago 850th aksyristos 631 123 60ms 3 Dec 2025 850th yeminghan2021 631 123 63ms 3 Feb 2026 852nd stackofbears 630 62 34ms 22 Dec 2025 853rd dokutan 630 95 7ms 25 Feb 2026 854th msbranicky 630 108 8ms 4 Dec 2025 855th jameswmccarty 628 77 716ms 8 Feb 2026 856th msbranicky 628 79 457ms 3 Dec 2025 856th madex 🇩🇪 628 79 447ms 11 days ago 856th Andrey2001 628 79 461ms 2 days ago 859th rucin93 🇵🇱 627 64 54ms 30 Oct 2025 860th HumanoidCPU 626 105 119ms 29 Nov 2025 861st alexsave 625 71 10ms 30 Nov 2025 862nd Waffle3z 622 87 2ms 26 Dec 2025 862nd Andriamanitra 🇫🇮 622 87 2ms 23 days ago 864th HumanoidCPU 621 85 91ms 29 Nov 2025 865th tomh1012 620 78 779ms 23 days ago 866th IISResetMe 619 78 343ms 30 Nov 2025 867th MeWhenI 🇻🇦 618 76 5ms 23 Nov 2025 868th HumanoidCPU 616 72 12ms 29 Nov 2025 868th olleicua 🇺🇸 616 72 10ms 8 Dec 2025 870th JOrE20 614 102 43ms 28 Nov 2025 871st MeWhenI 🇻🇦 613 104 1,025ms 23 Nov 2025 872nd HumanoidCPU 612 121 478ms 30 Nov 2025 873rd AlephSquirrel 611 79 304ms 30 Nov 2025 874th kmathis22 610 101 2,374ms 5 days ago 875th AstroOrbis 610 117 94ms 23 days ago 876th madeforlosers 608 73 10ms 8 days ago 877th RDShah 607 83 11ms 1 Dec 2025 878th MeWhenI 🇻🇦 607 100 6ms 24 Nov 2025 879th anter69 🇭🇺 606 74 35ms 5 Dec 2025 879th TheZwierzLF 🇵🇱 606 74 36ms 5 Jan 2026 First Prev 801–880 of 1,475 Next Last