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?
Reversi in all languages in bytes. 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 Bytes Time Submitted 321st albanian-laundromat 612 173 571ms 6 days ago 322nd MeWhenI 🇻🇦 611 219 7ms 10 Jun 2024 323rd olleicua 🇺🇸 609 132 43ms 25 Feb 2025 324th galloj 🇨🇿 607 123 28ms 9 Jun 2024 325th Shanethegamer 🇺🇸 606 189 600ms 12 Jun 2024 326th retrohun 606 202 182ms 19 Aug 2024 327th stefangimmillaro 602 124 35ms 12 Nov 2025 328th Shanethegamer 🇺🇸 600 203 368ms 13 Jun 2024 329th MeWhenI 🇻🇦 599 145 1,745ms 15 Sep 2025 330th CornerMercury 🇬🇧 598 183 1,912ms 24 Nov 2025 331st MeWhenI 🇻🇦 597 204 486ms 27 Jul 2024 332nd MeWhenI 🇻🇦 597 295 36ms 12 Jul 2025 333rd Shanethegamer 🇺🇸 591 136 46ms 1 Jun 2024 334th Flekay 🇩🇪 588 186 21ms 19 Feb 2026 335th Shanethegamer 🇺🇸 585 231 447ms 24 Sep 2025 336th CaedenHarper 🇨🇦 584 327 325ms 20 Nov 2025 337th Shanethegamer 🇺🇸 580 202 131ms 13 Jun 2024 338th snoozingnewt 🇨🇦 577 200 107ms 22 Nov 2025 339th bac0id 576 259 74ms 24 Jun 2024 340th MarcMush 🇫🇷 573 157 802ms 31 Jul 2024 341st annaproxy 570 192 199ms 28 Aug 2025 342nd Yewzir 🇧🇪 568 268 212ms 9 Jun 2024 343rd snoozingnewt 🇨🇦 563 252 120ms 20 Nov 2025 344th dokutan 561 133 30ms 15 Aug 2024 345th Shanethegamer 🇺🇸 560 189 6ms 28 Sep 2024 346th MeWhenI 🇻🇦 560 299 44ms 3 Sep 2024 347th Shanethegamer 🇺🇸 558 152 1,408ms 1 Jun 2024 348th Lv0Sys 🇵🇱 547 349 315ms 11 Dec 2025 349th KatieLG 🇬🇧 542 202 2,758ms 25 May 2025 350th dcgjb 538 155 1,454ms 4 Jun 2024 351st Shanethegamer 🇺🇸 535 228 5ms 13 Jun 2024 352nd InigoK 🇺🇸 534 205 25ms 22 Sep 2025 353rd hacker112 🇸🇪 534 213 11ms 27 Jun 2024 354th ndren 526 208 282ms 10 Jul 2025 355th jerrandolph 526 363 326ms 29 Sep 2025 356th KatieLG 🇬🇧 524 202 2,600ms 25 May 2025 357th bac0id 521 237 2ms 24 Jun 2024 358th Yax42 🇫🇷 518 261 508ms 16 Oct 2025 359th guilhem-roy 🇫🇷 516 212 2,261ms 22 Nov 2025 360th msbranicky 514 372 314ms 14 Aug 2024 361st elgan65536 🇺🇸 509 215 14ms 3 Oct 2024 361st jatloe 509 215 328ms 28 Oct 2024 363rd Yewzir 🇧🇪 505 265 7ms 9 Jun 2024 364th Yewzir 🇧🇪 505 323 6ms 9 Jun 2024 365th YAJUE114514 497 220 14ms 28 Dec 2025 366th h3ra993huskp 🇯🇵 494 274 611ms 30 Nov 2025 367th acollett89 493 231 11ms 18 Jul 2025 368th TobyBoyne 🇬🇧 491 223 17ms 6 Jun 2024 369th mousetail 🇳🇱 488 183 22ms 27 Sep 2024 370th Yewzir 🇧🇪 486 371 26ms 9 Jun 2024 371st msbranicky 483 315 223ms 14 Aug 2024 372nd didion0 🇺🇸 482 236 19ms 21 Feb 2025 373rd msbranicky 481 278 8ms 11 Aug 2024 374th bac0id 481 284 405ms 24 Jun 2024 375th mousetail 🇳🇱 476 230 23ms 22 Sep 2025 376th CaedenHarper 🇨🇦 472 232 24ms 11 Dec 2025 377th madeforlosers 472 241 49ms 18 Oct 2024 378th msbranicky 467 349 6ms 14 Aug 2024 379th coreynash 466 244 15ms 12 Jun 2024 380th dokutan 466 290 435ms 24 Sep 2025 381st Yewzir 🇧🇪 466 293 505ms 22 Dec 2024 382nd CaedenHarper 🇨🇦 458 231 862ms 11 Dec 2025 383rd CaedenHarper 🇨🇦 457 249 12ms 25 Sep 2025 384th CaedenHarper 🇨🇦 442 309 426ms 21 Oct 2025 385th tatzyr 🇯🇵 440 183 154ms 26 Mar 2025 386th madex 🇩🇪 433 253 21ms 23 Dec 2025 387th dokutan 433 271 16ms 3 Jun 2024 388th msbranicky 431 254 35ms 9 Aug 2024 389th wh3n3v3r 🇨🇿 429 255 52ms 12 Nov 2024 390th targrik 427 245 30ms 29 Jul 2025 391st bac0id 427 317 566ms 24 Jun 2024 392nd Bulmenisaurus 423 259 35ms 5 Jan 2025 393rd rucin93 🇵🇱 421 318 44ms 16 Jul 2024 394th JOrE20 420 271 47ms 12 Feb 2026 395th MeWhenI 🇻🇦 418 293 1,517ms 20 Jun 2024 396th msbranicky 413 256 724ms 2 Jun 2024 397th mathisfun271 413 265 31ms 7 Oct 2024 397th dokutan 413 265 18ms 11 days ago 399th dokutan 411 277 15ms 15 Jun 2025 400th dokutan 409 334 500ms 5 Jun 2024 First Prev 321–400 of 464 Next Last