The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 5 days. Why not try and solve them ahead of time?
ROT13 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 400th rhdqor213 813 81 2ms 9 Dec 2025 402nd edsrzf 🇳🇿 812 66 2,660ms 2 Nov 2025 403rd stefangimmillaro 811 126 170ms 14 Jan 2025 404th stefangimmillaro 810 102 10ms 2 Jan 2025 404th GolfingSuccess 🇬🇷 810 102 10ms 3 Jan 2025 404th kirjavascript 810 102 11ms 14 Feb 2025 404th junkondo-jp 810 102 15ms 30 May 2025 404th pardouin 🇫🇷 810 102 11ms 28 Jul 2025 409th SirBogman 🇺🇸 809 61 312ms 9 Jan 2025 410th HETHAT 🇩🇿 809 70 10ms 3 Aug 2025 410th bricknellj 809 70 11ms 30 Oct 2025 412th stefangimmillaro 809 135 275ms 2 Jan 2025 413th aksyristos 808 41 36ms 7 Jan 2025 413th CornerMercury 🇬🇧 808 41 36ms 17 Jan 2025 413th HumanoidCPU 808 41 37ms 1 Feb 2025 413th dokutan 808 41 37ms 4 Feb 2025 413th CaedenHarper 🇨🇦 808 41 36ms 7 Sep 2025 413th prestosilver 🇺🇸 808 41 35ms 18 Nov 2025 419th CLOStrophobic 🇮🇹 808 115 15ms 19 Jan 2025 419th kg583 🇺🇸 808 115 17ms 24 Feb 2026 421st GolfingSuccess 🇬🇷 806 104 451ms 31 Jan 2026 422nd Yax42 🇫🇷 804 89 406ms 18 Feb 2026 423rd adriweb 🇫🇷 804 105 2ms 8 Jan 2025 423rd FlyingPenguin223 804 105 2ms 7 Mar 2025 423rd frosster 🇨🇦 804 105 3ms 6 Feb 2026 426th bizy-coder 803 103 10ms 2 Jan 2025 426th DialFrost 🇸🇬 803 103 11ms 2 Jan 2025 426th Shanethegamer 🇺🇸 803 103 10ms 6 Jan 2025 426th XenThe 🇬🇧 803 103 13ms 1 Jul 2025 426th trinityy-7 803 103 11ms 21 Jul 2025 431st kaascevich 803 114 103ms 29 Jul 2025 432nd sean-niemann 🇺🇸 803 136 295ms 3 Jan 2025 433rd error256 802 79 108ms 9 hours ago 434th kg583 🇺🇸 801 88 7ms 15 Feb 2026 435th MeWhenI 🇻🇦 801 98 29ms 25 Nov 2025 436th stefangimmillaro 801 105 374ms 7 Oct 2025 437th AlephSquirrel 801 116 16ms 5 Jan 2025 438th tatzyr 🇯🇵 800 63 2,138ms 29 Jul 2025 439th edsrzf 🇳🇿 799 126 4ms 26 Aug 2025 440th Shanethegamer 🇺🇸 798 71 11ms 2 Jan 2025 440th aksyristos 798 71 11ms 3 Jan 2025 440th voytxt 🇨🇿 798 71 11ms 3 Jan 2025 440th maxgodfrey2004 🇨🇦 798 71 11ms 4 Jan 2025 440th mrmena 🇦🇺 798 71 11ms 5 Jan 2025 440th croc54 798 71 11ms 5 Jan 2025 440th nstearns96 🇬🇧 798 71 11ms 6 Jan 2025 440th rollershutter 798 71 11ms 6 Jan 2025 440th moustave 798 71 11ms 7 Jan 2025 440th jmerle 🇳🇱 798 71 10ms 7 Jan 2025 440th NickTheEASDude 🇺🇸 798 71 11ms 8 Jan 2025 440th btjones0 798 71 10ms 11 Jan 2025 440th psaban 798 71 11ms 12 Jan 2025 440th scpchicken 🇵🇼 798 71 10ms 13 Jan 2025 440th neihousaigaai 798 71 10ms 13 Jan 2025 440th DGipe 798 71 11ms 13 Jan 2025 440th hiichbindermax 798 71 10ms 14 Jan 2025 440th rschwa6308 🇺🇸 798 71 11ms 14 Jan 2025 440th ImpressedByRocks 798 71 29ms 17 Jan 2025 440th primo-ppcg 🇹🇭 798 71 10ms 21 Jan 2025 440th davecame 798 71 11ms 29 Jan 2025 440th andrewjc2000 798 71 11ms 28 Feb 2025 440th Pyroan 798 71 10ms 7 Mar 2025 440th Troon 798 71 11ms 14 Mar 2025 440th souta-1326 798 71 10ms 25 Mar 2025 440th connor-grady 798 71 11ms 18 May 2025 440th bknower 798 71 11ms 30 Jun 2025 440th muser-logiccpu 🇺🇦 798 71 11ms 24 Jul 2025 440th LuisGoncalves05 🇵🇹 798 71 11ms 27 Jul 2025 440th CamegaZFC 798 71 11ms 30 Jul 2025 440th shelerr 798 71 10ms 22 Aug 2025 440th InigoK 🇺🇸 798 71 11ms 28 Aug 2025 440th janlelis 798 71 12ms 22 Sep 2025 440th rustykitty 🇺🇸 798 71 10ms 28 Oct 2025 440th Cube14yt 798 71 10ms 13 Nov 2025 440th guilhem-roy 🇫🇷 798 71 11ms 22 Nov 2025 440th CommandLeo 🇮🇹 798 71 10ms 27 Nov 2025 440th jkelly467 798 71 10ms 10 Dec 2025 440th Languag3 798 71 11ms 12 Dec 2025 440th Aquateraneal 🇺🇸 798 71 10ms 14 Feb 2026 480th inventshah 798 105 445ms 26 Mar 2025 First Prev 401–480 of 1,065 Next Last