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?
Tic-tac-toe 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 561st blaztoma 🇱🇹 403 215 158ms 28 Nov 2025 562nd Waffle3z 402 231 3ms 7 Feb 2025 562nd Sciman101 402 231 5ms 17 Jan 2026 564th YAJUE114514 401 173 19ms 30 Jul 2025 564th aalec 401 173 14ms 8 Nov 2025 566th amazingalek 🇳🇴 399 197 553ms 4 Jan 2026 567th nstearns96 🇬🇧 397 175 16ms 4 Feb 2025 568th JOrE20 397 383 27ms 14 Feb 2026 569th NerdyMcNerd42 394 176 13ms 20 Feb 2025 570th jerrandolph 394 342 353ms 24 Sep 2025 571st HumanoidCPU 392 177 16ms 26 Jan 2025 572nd tomh1012 391 201 459ms 12 Sep 2025 573rd nemoyatpeace 390 178 13ms 13 Jan 2026 574th CarsonChr 🇺🇸 388 179 14ms 31 Jan 2025 575th yoshykai 386 268 510ms 30 Mar 2025 576th gastropner 384 181 23ms 10 Feb 2025 577th JOrE20 381 182 14ms 29 Jan 2026 578th snoozingnewt 🇨🇦 381 192 134ms 16 Sep 2025 579th JRaspass 🇬🇧 375 119 4ms 3 Feb 2025 580th aliakseikalosha 374 210 403ms 22 Jun 2025 581st adamnielson42 🇺🇸 371 187 14ms 10 Feb 2025 582nd madex 🇩🇪 369 353 325ms 28 Jan 2025 583rd Matter1024 🇮🇳 368 125 42ms 14 Feb 2026 584th HumanoidCPU 367 173 549ms 26 Jan 2025 585th Program-Pi 366 196 20ms 16 days ago 586th Alban-Boissard 365 190 16ms 14 Jun 2025 587th davidludwik2370 364 191 13ms 31 Jul 2025 587th To5BG 364 191 16ms 16 Nov 2025 589th Macweese 364 284 477ms 14 Feb 2026 590th IISResetMe 361 160 2,194ms 7 Jan 2026 591st madex 🇩🇪 359 128 39ms 31 Jan 2025 592nd michaelhodel 358 194 14ms 16 Nov 2025 593rd msbranicky 356 195 16ms 1 Feb 2025 594th AstroOrbis 351 198 20ms 10 Feb 2026 594th Andrey2001 351 198 14ms 14 Feb 2026 594th Aquateraneal 🇺🇸 351 198 14ms 17 days ago 597th zakariamouhid 348 206 17ms 8 Mar 2025 598th dokutan 347 328 4,408ms 28 Apr 2025 599th denkyuu1 346 133 54ms 8 days ago 600th viv511 345 274 2ms 7 Feb 2025 601st CaedenHarper 🇨🇦 341 334 62ms 12 Sep 2025 602nd ereztaiar 🇮🇱 341 395 316ms 8 Apr 2025 603rd MeWhenI 🇻🇦 341 446 27ms 13 Mar 2025 604th blaztoma 🇱🇹 338 224 7ms 22 Sep 2025 605th CaedenHarper 🇨🇦 337 213 13ms 23 Aug 2025 606th Schmitt-Very-Cool 337 307 705ms 3 Oct 2025 607th gigaprofisi 🇺🇸 331 217 14ms 4 Nov 2025 608th KatieLG 🇬🇧 330 428 14ms 27 Jun 2025 609th RedzGoose 🇦🇺 329 211 22ms 10 Feb 2025 610th aksyristos 324 214 14ms 21 Mar 2025 610th TheZwierzLF 🇵🇱 324 214 15ms 29 May 2025 612th HumanoidCPU 324 292 3ms 5 Jun 2025 613th yhm138 321 216 13ms 16 Feb 2025 613th te-chnical 321 216 14ms 1 Jan 2026 615th mbittner20 320 217 16ms 24 Feb 2025 615th aaardwark 320 217 23ms 31 May 2025 617th EthanJantz 313 222 15ms 10 Aug 2025 618th adaGrad1 311 223 18ms 3 Aug 2025 619th Ronterox 309 149 43ms 4 Feb 2026 620th The-Wolfson 308 302 110ms 5 Feb 2025 621st tomh1012 305 228 15ms 18 days ago 622nd CaedenHarper 🇨🇦 303 312 3ms 12 Sep 2025 623rd CarterStroik 302 307 4ms 13 Nov 2025 624th Wonamm 298 233 15ms 14 Feb 2025 624th TheAtrossian 298 233 12ms 15 Feb 2025 626th Mikey-Beep 🇬🇧 295 235 15ms 5 Oct 2025 627th FortuiteMan 🇫🇷 291 239 17ms 7 Jul 2025 628th vroup 🇩🇰 283 278 502ms 18 Aug 2025 629th Yewzir 🇧🇪 281 247 13ms 6 Feb 2025 630th TheZwierzLF 🇵🇱 279 165 51ms 6 Jan 2026 631st mousetail 🇳🇱 279 339 3ms 31 Jan 2025 632nd ehulinsky 🇺🇸 278 241 12ms 3 Apr 2025 633rd MiLk 277 251 15ms 19 Feb 2025 634th Shotokhan 268 259 17ms 25 Sep 2025 635th Zach1031 268 424 1,642ms 15 Nov 2025 636th Yewzir 🇧🇪 266 239 538ms 7 Feb 2025 637th Jacob385 266 389 537ms 14 Feb 2025 638th Stockoh 🇫🇷 264 263 109ms 13 Feb 2025 639th CaedenHarper 🇨🇦 263 572 2,131ms 23 Oct 2025 640th ibeucaly 261 516 377ms 11 Mar 2025 First Prev 561–640 of 754 Next Last