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?
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 300th Kacarott 🇦🇺 833 68 11ms 18 Jul 2025 300th cros107 🇦🇺 833 68 10ms 9 Sep 2025 300th blaztoma 🇱🇹 833 68 11ms 30 Oct 2025 300th edsrzf 🇳🇿 833 68 10ms 30 Oct 2025 300th Emutis 🇱🇹 833 68 29ms 2 Nov 2025 300th sisyphus-ppcg 🇦🇺 833 68 10ms 24 Nov 2025 300th StefanHabel 🇨🇦 833 68 11ms 10 days ago 328th Steffan153 🇫🇮 832 140 94ms 17 hours ago 329th albanian-laundromat 831 61 370ms 4 Aug 2025 329th KatieLG 🇬🇧 831 61 418ms 6 Oct 2025 331st edsrzf 🇳🇿 831 111 11ms 27 days ago 332nd frankgraziano 831 215 3,677ms 11 Aug 2025 333rd GolfingSuccess 🇬🇷 830 224 1,721ms 11 Jan 2026 334th DialFrost 🇸🇬 829 46 685ms 15 Feb 2026 335th edsrzf 🇳🇿 829 89 8ms 14 Oct 2025 336th DialFrost 🇸🇬 828 40 35ms 1 Jan 2025 336th jmerle 🇳🇱 828 40 35ms 7 Jan 2025 336th Andriamanitra 🇫🇮 828 40 36ms 12 Jan 2025 336th frankgraziano 828 40 36ms 12 May 2025 336th Just4FunCoder 828 40 33ms 14 Sep 2025 336th albanian-laundromat 828 40 33ms 30 Oct 2025 342nd iczelia 🇩🇪 827 45 4ms 21 Sep 2025 343rd edsrzf 🇳🇿 827 61 1,312ms 20 Jul 2025 344th ovs-code 🇩🇪 827 100 11ms 7 Jan 2025 345th primo-ppcg 🇹🇭 827 216 3,737ms 13 Aug 2025 346th error256 825 122 25ms 8 Jan 2025 347th kg583 🇺🇸 825 134 42ms 20 Dec 2025 348th saito-ta 🇯🇵 824 80 4ms 13 Jan 2025 348th GolfingSuccess 🇬🇷 824 80 2ms 24 days ago 350th zacjl 824 105 15ms 8 Jan 2025 351st m-tkach 🇺🇦 822 102 467ms 7 Jan 2025 352nd stefangimmillaro 821 69 10ms 31 Dec 2024 352nd bizy-coder 821 69 11ms 2 Jan 2025 352nd MeWhenI 🇻🇦 821 69 10ms 3 Jan 2025 352nd msbranicky 821 69 10ms 4 Jan 2025 352nd orthoplex 🇨🇽 821 69 11ms 5 Jan 2025 352nd inventshah 821 69 10ms 6 Jan 2025 352nd ridingqwerty 🇺🇸 821 69 11ms 7 Jan 2025 352nd SirBogman 🇺🇸 821 69 10ms 9 Jan 2025 352nd inverseLorentz 🇦🇺 821 69 10ms 10 Jan 2025 352nd 5cw 🇺🇸 821 69 11ms 11 Jan 2025 352nd decorator-factory 821 69 10ms 12 Jan 2025 352nd asterized 821 69 11ms 13 Jan 2025 352nd bob-th 821 69 10ms 15 Jan 2025 352nd annaproxy 821 69 11ms 22 Jan 2025 352nd alemelis 821 69 34ms 4 Jun 2025 352nd jipsong 🇩🇪 821 69 30ms 9 Jun 2025 352nd nwellnhof 🇩🇪 821 69 11ms 9 Jul 2025 352nd wuduculfre 821 69 11ms 22 Jul 2025 352nd FEZfan 🇦🇺 821 69 11ms 1 Nov 2025 352nd ahmetdemirag 🇨🇾 821 69 10ms 24 Dec 2025 352nd Lv0Sys 🇵🇱 821 69 11ms 22 Feb 2026 373rd stefangimmillaro 821 87 412ms 14 Jan 2025 373rd SirBogman 🇺🇸 821 87 428ms 23 Jan 2025 373rd tomtheisen 🇺🇸 821 87 409ms 15 Feb 2025 373rd namelessiw 821 87 394ms 24 Jul 2025 377th ovs-code 🇩🇪 820 79 179ms 17 Apr 2025 378th edsrzf 🇳🇿 819 135 41ms 16 Aug 2025 379th GrayJoKing 🇦🇺 818 96 35ms 25 Nov 2025 380th MeWhenI 🇻🇦 818 101 12ms 26 Feb 2025 381st Natanaelel 🇸🇪 816 44 103ms 13 Jan 2025 382nd kg583 🇺🇸 816 106 26ms 13 days ago 383rd saito-ta 🇯🇵 815 26 56ms 12 Jan 2025 384th DialFrost 🇸🇬 815 87 440ms 1 Jan 2025 384th edsrzf 🇳🇿 815 87 482ms 2 Nov 2025 386th rucin93 🇵🇱 815 89 159ms 7 Dec 2025 386th sean-niemann 🇺🇸 815 89 164ms 7 Dec 2025 388th saito-ta 🇯🇵 815 115 20ms 12 Jan 2025 389th GolfingSuccess 🇬🇷 813 26 3ms 20 Mar 2025 390th stefangimmillaro 813 62 1,282ms 4 Jan 2025 391st m-tkach 🇺🇦 813 81 2ms 7 Jan 2025 391st rhdqor213 813 81 2ms 9 Dec 2025 393rd edsrzf 🇳🇿 812 66 2,660ms 2 Nov 2025 394th stefangimmillaro 810 102 10ms 2 Jan 2025 394th GolfingSuccess 🇬🇷 810 102 10ms 3 Jan 2025 394th kirjavascript 810 102 11ms 14 Feb 2025 394th junkondo-jp 810 102 15ms 30 May 2025 394th pardouin 🇫🇷 810 102 11ms 28 Jul 2025 399th stefangimmillaro 810 126 170ms 14 Jan 2025 400th SirBogman 🇺🇸 809 61 312ms 9 Jan 2025 First Prev 321–400 of 1,052 Next Last