The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 6 days. Why not try and solve them ahead of time?
Spelling Numbers 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 561st emgordon154 597 405 1,544ms 20 Nov 2024 562nd janbehrens 🇩🇪 596 403 443ms 5 Jul 2021 563rd bac0id 594 584 2,867ms 10 Jan 2025 564th BlueSky555 592 586 2,825ms 8 Aug 2024 565th lahell 591 418 404ms 17 Jun 2020 566th msbranicky 591 603 258ms 6 Oct 2023 567th BettaGeorge 590 300 4ms 24 Dec 2017 568th Waffle3z 590 405 35ms 6 Jul 2021 569th namelessiw 590 407 454ms 10 Oct 2025 570th CaedenHarper 🇨🇦 589 335 122ms 14 days ago 571st bzijlema 🇳🇱 585 325 14ms 7 Jul 2025 572nd mrmena 🇦🇺 584 580 44ms 8 May 2024 573rd albanian-laundromat 583 371 5ms 11 Jul 2025 574th boxjelly 581 565 4ms 17 Feb 2021 575th kjetillll 🇮🇩 580 305 5ms 19 May 2021 576th sean-niemann 🇺🇸 580 414 516ms 24 Sep 2025 576th dokutan 580 414 581ms 23 Oct 2025 578th Florian-Mt 580 464 13ms 12 Jul 2024 579th cmayer777 580 598 72ms 19 Dec 2022 580th bricknellj 579 328 14ms 19 Jul 2024 581st SkimnerPhi 579 465 11ms 5 Dec 2020 582nd anter69 🇭🇺 578 329 14ms 13 Mar 2025 583rd sebipopa 🇷🇴 576 467 14ms 12 Sep 2022 583rd Ow0cast 576 467 13ms 17 Oct 2025 585th ETHproductions 🇺🇸 575 468 16ms 19 Dec 2018 586th MeWhenI 🇻🇦 573 309 4ms 16 Apr 2023 587th Kacarott 🇦🇺 572 396 86ms 13 Sep 2024 588th sultan 571 421 442ms 26 Feb 2024 589th ian-h-chamberlain 🇺🇸 571 640 293ms 23 Nov 2025 590th ericlangedijk 🇸🇮 569 702 27ms 18 Feb 2022 591st CaedenHarper 🇨🇦 565 425 435ms 3 days ago 592nd janbehrens 🇩🇪 564 314 6ms 28 May 2021 593rd stefangimmillaro 564 426 500ms 6 Oct 2025 594th lacroixjonathan87 562 487 9ms 6 Sep 2020 595th janbehrens 🇩🇪 559 340 14ms 17 Jun 2023 596th MeWhenI 🇻🇦 557 369 36ms 13 Dec 2021 597th ahmetdemirag 🇨🇾 556 342 13ms 11 Aug 2024 598th TFeld00 🇩🇰 554 343 35ms 11 Nov 2020 598th CornerMercury 🇬🇧 554 343 13ms 27 Jan 2026 600th yokasuretsu 552 225 139ms 30 Nov 2021 601st annaproxy 550 560 18ms 13 Jan 2023 602nd neihousaigaai 549 346 14ms 7 Jul 2021 602nd sultan 549 346 14ms 26 Feb 2024 602nd 051 🇸🇬 549 346 21ms 28 Feb 2024 605th marcin7Cd 548 347 20ms 16 Dec 2020 606th TimCurwick 🇺🇸 548 451 330ms 27 Jan 2021 607th lrustand 546 348 14ms 18 Jan 2018 608th jared-hughes 545 349 13ms 25 Mar 2022 608th shelerr 545 349 14ms 23 Aug 2025 610th akshatj27 🇦🇶 545 494 13ms 11 Jan 2022 611th TornadoCookie 543 605 3ms 25 Dec 2022 612th Attero 🇸🇪 541 351 13ms 13 Oct 2020 613th zakariamouhid 540 498 12ms 14 May 2023 614th scpchicken 🇵🇼 538 329 6ms 30 Jan 2023 615th inventshah 537 354 33ms 27 Jan 2023 615th TaserTheFox 🇺🇸 537 354 22ms 20 Apr 2023 617th KevinMarquette 🇺🇸 536 461 326ms 8 Jun 2020 618th OllieBoyne 🇬🇧 535 355 16ms 18 Apr 2022 619th lynn 535 479 1,036ms 25 Jul 2021 620th jacklynnepenick 534 356 13ms 17 Aug 2021 620th annaproxy 534 356 21ms 14 Aug 2022 622nd keelanfh 532 357 15ms 14 Mar 2023 623rd OddballGreg 532 449 41ms 26 Sep 2020 624th daedals 531 358 15ms 22 May 2019 624th GolfingSuccess 🇬🇷 531 358 15ms 14 Mar 2025 626th logvp 529 359 13ms 27 Dec 2023 627th annaproxy 529 557 435ms 29 Mar 2022 628th galloj 🇨🇿 528 361 277ms 26 Feb 2023 629th AlexDaniel 🇪🇪 527 236 156ms 14 Nov 2017 630th cmdrsabre 527 257 901ms 7 Feb 2020 631st yzhs 🇩🇪 526 361 14ms 29 Feb 2020 631st duckyluuk 🇳🇱 526 361 34ms 6 Sep 2024 631st Pyroan 526 361 14ms 8 Mar 2025 634th jatloe 525 362 16ms 28 Oct 2024 634th Artemis21 🇬🇧 525 362 15ms 5 Dec 2025 634th Flekay 🇩🇪 525 362 19ms 19 Feb 2026 634th snoozingnewt 🇨🇦 525 362 19ms 20 Feb 2026 638th fourth-bit 524 363 13ms 14 Jul 2023 638th mathisfun271 524 363 14ms 23 Nov 2023 640th tomh1012 523 564 476ms 20 days ago First Prev 561–640 of 1,084 Next Last