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?
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 396th prestosilver 🇺🇸 808 41 35ms 18 Nov 2025 402nd CLOStrophobic 🇮🇹 808 115 15ms 19 Jan 2025 402nd kg583 🇺🇸 808 115 17ms 24 Feb 2026 404th stefangimmillaro 808 135 275ms 2 Jan 2025 405th kg583 🇺🇸 806 88 7ms 15 Feb 2026 406th GolfingSuccess 🇬🇷 805 104 444ms 31 Jan 2026 407th Yax42 🇫🇷 803 89 406ms 18 Feb 2026 408th bizy-coder 803 103 9ms 2 Jan 2025 408th DialFrost 🇸🇬 803 103 9ms 2 Jan 2025 408th Shanethegamer 🇺🇸 803 103 12ms 6 Jan 2025 408th XenThe 🇬🇧 803 103 11ms 1 Jul 2025 408th trinityy-7 803 103 10ms 21 Jul 2025 413th kaascevich 803 114 103ms 29 Jul 2025 414th adriweb 🇫🇷 802 105 2ms 8 Jan 2025 414th FlyingPenguin223 802 105 2ms 7 Mar 2025 414th frosster 🇨🇦 802 105 3ms 6 Feb 2026 417th sean-niemann 🇺🇸 802 136 295ms 3 Jan 2025 418th MeWhenI 🇻🇦 801 98 29ms 25 Nov 2025 419th AlephSquirrel 801 116 16ms 5 Jan 2025 420th stefangimmillaro 800 105 374ms 7 Oct 2025 421st tatzyr 🇯🇵 799 63 2,138ms 29 Jul 2025 422nd Shanethegamer 🇺🇸 798 71 11ms 2 Jan 2025 422nd aksyristos 798 71 11ms 3 Jan 2025 422nd voytxt 🇨🇿 798 71 11ms 3 Jan 2025 422nd maxgodfrey2004 🇨🇦 798 71 11ms 4 Jan 2025 422nd mrmena 🇦🇺 798 71 11ms 5 Jan 2025 422nd croc54 798 71 11ms 5 Jan 2025 422nd nstearns96 🇬🇧 798 71 11ms 6 Jan 2025 422nd rollershutter 798 71 11ms 6 Jan 2025 422nd moustave 798 71 11ms 7 Jan 2025 422nd jmerle 🇳🇱 798 71 10ms 7 Jan 2025 422nd NickTheEASDude 🇺🇸 798 71 11ms 8 Jan 2025 422nd btjones0 798 71 10ms 11 Jan 2025 422nd psaban 798 71 11ms 12 Jan 2025 422nd scpchicken 🇵🇼 798 71 10ms 13 Jan 2025 422nd neihousaigaai 798 71 10ms 13 Jan 2025 422nd DGipe 798 71 11ms 13 Jan 2025 422nd hiichbindermax 798 71 10ms 14 Jan 2025 422nd rschwa6308 🇺🇸 798 71 11ms 14 Jan 2025 422nd ImpressedByRocks 798 71 29ms 17 Jan 2025 422nd primo-ppcg 🇹🇭 798 71 10ms 21 Jan 2025 422nd davecame 798 71 11ms 29 Jan 2025 422nd andrewjc2000 798 71 11ms 28 Feb 2025 422nd Pyroan 798 71 10ms 7 Mar 2025 422nd Troon 798 71 11ms 14 Mar 2025 422nd souta-1326 798 71 10ms 25 Mar 2025 422nd connor-grady 798 71 11ms 18 May 2025 422nd bknower 798 71 11ms 30 Jun 2025 422nd muser-logiccpu 🇺🇦 798 71 11ms 24 Jul 2025 422nd LuisGoncalves05 🇵🇹 798 71 11ms 27 Jul 2025 422nd CamegaZFC 798 71 11ms 30 Jul 2025 422nd shelerr 798 71 10ms 22 Aug 2025 422nd InigoK 🇺🇸 798 71 11ms 28 Aug 2025 422nd janlelis 798 71 12ms 22 Sep 2025 422nd rustykitty 🇺🇸 798 71 10ms 28 Oct 2025 422nd Cube14yt 798 71 10ms 13 Nov 2025 422nd guilhem-roy 🇫🇷 798 71 11ms 22 Nov 2025 422nd CommandLeo 🇮🇹 798 71 10ms 27 Nov 2025 422nd jkelly467 798 71 10ms 10 Dec 2025 422nd Languag3 798 71 11ms 12 Dec 2025 422nd Aquateraneal 🇺🇸 798 71 10ms 14 Feb 2026 462nd inventshah 797 105 450ms 26 Mar 2025 462nd Mukundan314 797 105 430ms 28 Apr 2025 464th DialFrost 🇸🇬 796 62 267ms 4 Jan 2025 464th bitsandbeyond 🇳🇱 796 62 331ms 3 Nov 2025 466th kg583 🇺🇸 796 153 82ms 15 hours ago 467th CarsonChr 🇺🇸 795 104 11ms 5 Jan 2025 467th m-tkach 🇺🇦 795 104 14ms 7 Jan 2025 467th jared-hughes 795 104 11ms 7 Jan 2025 467th Lv0Sys 🇵🇱 795 104 13ms 22 Feb 2026 471st DialFrost 🇸🇬 795 106 2ms 2 Jan 2025 471st NickTheEASDude 🇺🇸 795 106 3ms 8 Jan 2025 473rd edsrzf 🇳🇿 795 126 4ms 26 Aug 2025 474th BREMAUCY 🇫🇷 794 38 3ms 9 Jan 2025 475th snoozingnewt 🇨🇦 794 48 918ms 10 Dec 2025 475th error256 794 48 749ms 14 Feb 2026 477th retrohun 794 118 197ms 26 Jan 2025 478th jared-hughes 794 185 18ms 6 Apr 2025 479th JohandeRuiter 🇳🇱 793 83 4ms 21 Jan 2025 479th error256 793 83 4ms 25 Aug 2025 First Prev 401–480 of 1,037 Next Last