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?
DFA Simulator 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 401st bac0id 572 297 445ms 8 Jan 2025 402nd tigerdan2 🇩🇪 572 332 480ms 30 Nov 2025 403rd neihousaigaai 570 247 12ms 7 Oct 2024 404th blaztoma 🇱🇹 569 151 4ms 12 Jan 2026 405th MeWhenI 🇻🇦 566 257 69ms 6 Nov 2023 406th JunkIce 565 249 11ms 9 Mar 2025 407th MeWhenI 🇻🇦 564 188 295ms 7 Dec 2023 408th Yax42 🇫🇷 561 204 14ms 13 Feb 2026 409th tomh1012 556 259 488ms 21 days ago 410th galloj 🇨🇿 554 254 11ms 24 Nov 2023 410th MaxElf999 554 254 13ms 9 Feb 2024 412th bac0id 548 274 2ms 8 Jan 2025 413th Shanethegamer 🇺🇸 544 210 3ms 1 Nov 2023 414th janAkali 🇷🇺 544 268 419ms 7 Jun 2025 415th FlorianCassayre 🇫🇷 541 260 11ms 3 Nov 2023 416th CaedenHarper 🇨🇦 539 208 1,172ms 20 Sep 2025 417th logvp 539 261 12ms 6 Oct 2024 418th za3k 537 262 12ms 22 Jul 2025 419th CaedenHarper 🇨🇦 530 391 301ms 2 Nov 2025 420th KatieLG 🇬🇧 523 207 1,204ms 15 Oct 2024 421st JunkIce 523 241 679ms 9 Mar 2025 422nd BREMAUCY 🇫🇷 521 270 13ms 21 Aug 2025 423rd FortuiteMan 🇫🇷 518 272 13ms 14 Oct 2024 424th Aurel300 🇨🇭 518 405 279ms 21 Jun 2024 425th MeWhenI 🇻🇦 517 221 13ms 20 Jun 2024 425th HumanoidCPU 517 221 10ms 23 Dec 2025 427th snoozingnewt 🇨🇦 515 240 19ms 18 Oct 2025 428th albanian-laundromat 513 223 7ms 2 Jul 2025 429th alexjurkiewicz 🇦🇺 512 275 12ms 14 Nov 2023 430th MeWhenI 🇻🇦 508 221 1,108ms 30 Aug 2025 431st snoozingnewt 🇨🇦 508 374 406ms 18 Oct 2025 432nd KatieLG 🇬🇧 507 183 37ms 9 Jan 2026 433rd FranklinJiaChen 506 278 13ms 4 Jul 2024 434th IISResetMe 505 210 839ms 2 Dec 2025 435th AlephSquirrel 501 360 6ms 14 May 2025 436th dokutan 497 283 13ms 5 Jul 2024 437th MateuszPietrzak 🇵🇱 494 344 67ms 19 Nov 2023 438th TheZwierzLF 🇵🇱 492 286 32ms 5 Jan 2026 439th CaedenHarper 🇨🇦 485 236 10ms 15 Sep 2025 440th jelleromer 485 290 25ms 19 Nov 2023 441st madeforlosers 480 238 15ms 5 Nov 2025 442nd Shanethegamer 🇺🇸 478 180 6ms 9 Nov 2023 443rd snoozingnewt 🇨🇦 475 307 366ms 18 Oct 2025 444th nemoyatpeace 474 297 21ms 29 Dec 2025 444th Lv0Sys 🇵🇱 474 297 12ms 27 days ago 446th jerrandolph 473 438 296ms 1 Nov 2023 447th BREMAUCY 🇫🇷 472 267 624ms 21 Aug 2025 448th msbranicky 472 298 12ms 1 Nov 2023 449th mbittner20 471 299 11ms 12 Feb 2024 450th MeWhenI 🇻🇦 464 308 9ms 27 Jun 2024 451st roguh 🇬🇹 464 324 2ms 15 Oct 2024 452nd Lv0Sys 🇵🇱 464 364 583ms 22 days ago 453rd snoozingnewt 🇨🇦 463 247 10ms 18 Oct 2025 454th Yewzir 🇧🇪 462 305 12ms 9 Dec 2025 455th haighd 460 306 12ms 21 Nov 2023 456th dokutan 459 275 602ms 5 Jul 2024 457th madex 🇩🇪 454 310 12ms 8 Oct 2025 458th TheZwierzLF 🇵🇱 452 279 711ms 5 Jan 2026 459th dokutan 432 281 694ms 18 Mar 2025 460th snoozingnewt 🇨🇦 432 323 126ms 18 Oct 2025 461st blaztoma 🇱🇹 431 453 112ms 28 Nov 2025 462nd jgbaldwinbrown 430 349 2ms 14 Mar 2024 463rd snoozingnewt 🇨🇦 430 395 3,095ms 18 Oct 2025 464th snoozingnewt 🇨🇦 428 267 3ms 18 Oct 2025 465th msbranicky 423 298 679ms 17 Jan 2024 466th TheZwierzLF 🇵🇱 420 221 58ms 6 Jan 2026 467th RZ781 418 337 12ms 19 Nov 2023 468th snoozingnewt 🇨🇦 417 457 35ms 18 Oct 2025 469th snoozingnewt 🇨🇦 415 207 4ms 18 Oct 2025 470th zakariamouhid 414 276 14ms 1 Nov 2023 471st Babafaba 414 340 13ms 17 Nov 2025 472nd Schmitt-Very-Cool 411 462 472ms 26 Sep 2025 473rd Lv0Sys 🇵🇱 407 281 13ms 27 days ago 474th AstroOrbis 407 346 12ms 9 days ago 475th snoozingnewt 🇨🇦 398 492 44ms 18 Oct 2025 476th retrohun 391 339 56ms 18 Nov 2023 477th CaedenHarper 🇨🇦 388 489 410ms 7 Oct 2025 478th Babafaba 379 333 682ms 17 Nov 2025 479th snoozingnewt 🇨🇦 379 364 2ms 18 Oct 2025 480th jensdewaard 378 372 15ms 19 Nov 2023 First Prev 401–480 of 523 Next Last