The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 4 days. Why not try and solve them ahead of time?
Reversi 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 401st CaedenHarper 🇨🇦 392 343 456ms 7 Oct 2025 402nd LHLaurini 🇧🇷 390 314 2ms 29 Jun 2024 403rd InigoK 🇺🇸 388 205 25ms 22 Sep 2025 404th dokutan 376 273 3,093ms 23 Oct 2024 405th guilhem-roy 🇫🇷 375 212 2,261ms 22 Nov 2025 406th elgan65536 🇺🇸 370 215 14ms 3 Oct 2024 407th blaztoma 🇱🇹 367 377 128ms 28 Nov 2025 408th YAJUE114514 361 220 14ms 28 Dec 2025 409th TobyBoyne 🇬🇧 357 223 17ms 6 Jun 2024 410th msbranicky 356 288 3,356ms 9 Jan 2025 411th CaedenHarper 🇨🇦 355 237 2,322ms 30 Sep 2025 412th tomh1012 353 384 564ms 12 Nov 2025 413th HumanoidCPU 351 230 459ms 31 Dec 2025 414th CaedenHarper 🇨🇦 349 231 862ms 11 Dec 2025 415th mousetail 🇳🇱 346 230 23ms 22 Sep 2025 416th CaedenHarper 🇨🇦 343 232 24ms 11 Dec 2025 417th MichalMarsalek 🇨🇿 343 352 432ms 7 Jun 2024 418th KatieLG 🇬🇧 341 398 444ms 14 Oct 2024 419th HumanoidCPU 340 234 21ms 31 Dec 2025 420th IISResetMe 333 232 1,456ms 14 Jun 2024 421st gigaprofisi 🇺🇸 318 308 13ms 1 Nov 2025 422nd msbranicky 315 256 724ms 2 Jun 2024 423rd madex 🇩🇪 314 253 21ms 23 Dec 2025 424th msbranicky 313 254 35ms 9 Aug 2024 425th stefangabos 🇷🇴 313 313 12ms 17 Nov 2025 426th zakariamouhid 310 316 12ms 8 Jun 2024 427th Bulmenisaurus 307 259 35ms 5 Jan 2025 428th madex 🇩🇪 306 320 13ms 6 Jun 2024 429th mathisfun271 300 265 31ms 7 Oct 2024 430th msbranicky 299 294 213ms 18 Sep 2024 431st Yax42 🇫🇷 276 421 155ms 7 Oct 2025 432nd Yax42 🇫🇷 268 245 132ms 7 Oct 2025 433rd alemelis 260 306 21ms 17 Oct 2024 434th klixel 🇨🇦 253 314 280ms 14 Jul 2025 435th mbittner20 243 327 18ms 28 Apr 2025 436th markusgraube 242 329 17ms 1 Jul 2024 437th FortuiteMan 🇫🇷 238 334 23ms 27 Nov 2025 438th knutae 🇳🇴 232 343 21ms 23 Jun 2024 438th jameswmccarty 232 343 29ms 11 Oct 2024 440th mrmena 🇦🇺 229 636 44ms 9 Jun 2024 441st adamnielson42 🇺🇸 209 380 16ms 16 Oct 2024 442nd FlorianCassayre 🇫🇷 201 396 55ms 1 Jun 2024 443rd croc54 197 403 14ms 3 Feb 2025 444th jtaxen 187 425 56ms 3 Jun 2024 445th tomh1012 186 427 20ms 19 days ago 446th iczelia 🇩🇪 159 499 12ms 23 Oct 2025 447th muser-logiccpu 🇺🇦 157 508 17ms 21 Aug 2025 448th two-bad 🇬🇧 154 638 16ms 10 Aug 2025 449th scpchicken 🇵🇼 150 529 12ms 1 Jun 2024 450th Jacob385 149 903 538ms 22 Jun 2024 451st hiichbindermax 146 545 15ms 4 Jun 2024 451st KatieLG-Transpiler 🇬🇧 146 545 14ms 16 Aug 2024 453rd Msleizak 🇫🇷 107 725 344ms 23 Jul 2025 454th KatieLG 🇬🇧 99 3,659 90ms 9 Jun 2024 455th Zhenyu-Bo 95 833 12ms 1 Aug 2025 456th AidanWalter 43 1,869 14ms 28 Nov 2025 457th ovs-code 🇩🇪 0 90 14ms 20 Jun 2025 458th error256 0 121 1,776ms 4 May 2025 459th aiwana 0 135 38ms 22 Oct 2025 460th dokutan 0 168 63ms 8 Feb 2026 461st edsrzf 🇳🇿 0 170 240ms 29 May 2025 462nd dokutan 0 171 62ms 28 Jun 2025 463rd Yewzir 🇧🇪 0 276 3ms 12 Feb 2026 First Prev 401–463 of 463
