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 880th matsagad 446 127 35ms 16 Jan 2025 882nd nullshallot 445 111 356ms 5 Jan 2025 883rd mhgockel 445 148 4ms 21 Jun 2025 884th driri85 439 129 11ms 7 Jan 2025 884th tjwrenn 439 129 11ms 27 Jan 2025 886th Chinay-Domitrix 🇺🇸 438 124 2,797ms 22 days ago 887th snoozingnewt 🇨🇦 437 253 40ms 2 Nov 2025 888th jtaxen 433 131 49ms 27 Jan 2025 889th isaiah0311 🇺🇸 433 152 5ms 1 Feb 2026 890th iczelia 🇩🇪 432 163 5ms 21 Sep 2025 891st jameswmccarty 429 132 12ms 7 Mar 2025 892nd blaztoma 🇱🇹 426 107 321ms 29 Oct 2025 893rd dokutan 420 109 75ms 16 Apr 2025 894th Ailko 🇧🇪 420 135 29ms 17 Jan 2025 894th itljan30 420 135 12ms 26 Jan 2025 894th smilesformiles3 420 135 18ms 18 Jun 2025 897th CaedenHarper 🇨🇦 415 51 81ms 13 days ago 898th non-bin 413 200 11ms 28 Jun 2025 899th CaedenHarper 🇨🇦 411 235 6ms 14 Nov 2025 900th snoozingnewt 🇨🇦 409 241 43ms 2 Nov 2025 901st snooze92 🇫🇷 408 139 11ms 5 Mar 2025 902nd snoozingnewt 🇨🇦 408 247 26ms 2 Nov 2025 903rd brimstonetrader 405 140 18ms 6 Jan 2025 904th snoozingnewt 🇨🇦 405 247 5ms 2 Nov 2025 905th HumanoidCPU 403 125 1,296ms 6 Nov 2025 906th KatieLG 🇬🇧 402 85 21ms 6 Jan 2025 907th PyryL 🇫🇮 402 141 11ms 22 Jan 2025 908th KatieLG 🇬🇧 402 270 32ms 5 Jan 2025 909th madex 🇩🇪 399 142 18ms 4 Jan 2025 910th dokutan 397 157 194ms 13 Nov 2025 911th galloj 🇨🇿 396 143 16ms 23 Jan 2025 912th TaserTheFox 🇺🇸 391 145 12ms 22 Feb 2025 913th KatieLG 🇬🇧 390 216 2ms 2 Oct 2025 914th KatieLG 🇬🇧 387 183 145ms 21 Nov 2025 915th vyx777 386 214 10ms 11 Jan 2025 916th gnuvince 384 55 2ms 29 Jun 2025 917th martinorav 383 148 13ms 20 Jan 2025 917th qwjhvbxi 383 148 18ms 21 Jan 2025 919th ComputerKWasTaken 🇺🇸 378 150 12ms 20 Jan 2025 920th The-Wolfson 378 242 102ms 22 Jan 2025 921st snoozingnewt 🇨🇦 375 192 9ms 2 Nov 2025 922nd snoozingnewt 🇨🇦 375 239 15ms 2 Nov 2025 923rd atazzam 🇺🇸 373 152 12ms 16 Jan 2025 923rd Andrey2001 373 152 12ms 1 Feb 2026 925th MeWhenI 🇻🇦 370 103 1,352ms 15 Sep 2025 926th Zhenyu-Bo 359 158 11ms 1 Aug 2025 927th Andrey2001 352 144 463ms 28 Jan 2026 928th mbittner20 352 161 12ms 7 Feb 2025 929th shaneliu-zf 🇹🇼 345 191 2ms 16 Apr 2025 930th matejmatik123 🇸🇰 345 243 1,417ms 15 Dec 2025 931st MiffOttah 343 208 448ms 3 Jan 2026 931st qrakhen 343 208 450ms 18 Feb 2026 933rd WillowWispy 337 168 12ms 22 Mar 2025 934th chartung17 335 169 21ms 7 Apr 2025 935th HumanoidCPU 334 274 102ms 1 Feb 2025 936th dokutan 330 218 96ms 26 Jan 2026 937th Benned-H 315 180 12ms 12 Jan 2025 938th scpchicken 🇵🇼 298 71 3ms 11 days ago 939th Scenes7 298 190 19ms 9 Jan 2025 939th 40fied4t 298 190 41ms 15 May 2025 941st zt14427 295 223 5ms 18 Jan 2025 942nd firewoods1978 294 193 11ms 13 Jan 2025 943rd msbranicky 288 354 206ms 6 Jan 2025 944th Bananapants22 275 206 14ms 10 Jan 2025 944th robbertvz 275 206 12ms 29 Dec 2025 946th error-could-not-find-name 272 78 192ms 11 Mar 2025 947th msbranicky 272 200 2,606ms 9 Jan 2025 948th olleicua 🇺🇸 272 355 6ms 6 Jun 2025 949th dokutan 270 357 6ms 8 Jan 2025 950th Kokusui 🇯🇵 259 144 8ms 6 Feb 2025 951st FortuiteMan 🇫🇷 257 250 34ms 29 Sep 2025 952nd codeman4033 251 226 12ms 21 Jan 2025 953rd mathomp4 248 398 40ms 10 Jan 2025 954th BREMAUCY 🇫🇷 239 71 1,023ms 11 Dec 2025 955th gpikmddk 230 310 403ms 3 Nov 2025 956th Msleizak 🇫🇷 214 231 424ms 20 Jan 2025 957th dokutan 202 189 1,346ms 29 Aug 2025 958th dokutan 198 417 12ms 3 Jul 2025 959th dokutan 184 1,012 1,445ms 12 Jan 2025 960th dokutan 178 513 845ms 3 Feb 2026 First Prev 881–960 of 1,037 Next Last