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?
Forsyth–Edwards Notation 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 560th knutae 🇳🇴 570 143 9ms 13 Nov 2023 560th davecame 570 143 16ms 30 Nov 2023 560th keelimeguy 🇺🇸 570 143 32ms 7 May 2025 560th stefangimmillaro 570 143 11ms 23 May 2025 565th kkoenig 570 275 289ms 13 Sep 2024 566th GolfingSuccess 🇬🇷 569 133 456ms 2 Mar 2024 567th madex 🇩🇪 567 204 2ms 11 days ago 568th Aurel300 🇨🇭 567 266 235ms 21 Jul 2024 569th cros107 🇦🇺 566 144 10ms 26 Oct 2023 570th MeWhenI 🇻🇦 566 173 116ms 1 May 2023 571st msbranicky 565 267 191ms 1 Oct 2023 572nd dokutan 564 205 1ms 22 Apr 2024 573rd mathisfun271 562 145 9ms 18 Feb 2024 573rd neihousaigaai 562 145 11ms 10 Apr 2025 575th SirBogman 🇺🇸 561 135 489ms 16 Jan 2024 576th Shanethegamer 🇺🇸 561 147 1,024ms 17 May 2023 577th snoozingnewt 🇨🇦 560 107 3ms 31 Oct 2025 578th MeWhenI 🇻🇦 560 139 969ms 15 Sep 2025 579th snoozingnewt 🇨🇦 560 175 435ms 31 Oct 2025 580th OllieBoyne 🇬🇧 558 146 10ms 1 May 2023 580th Chimplement 558 146 10ms 13 Dec 2023 582nd msbranicky 557 235 2ms 11 Oct 2023 583rd MeWhenI 🇻🇦 556 98 2ms 1 May 2023 584th KatieLG 🇬🇧 556 287 2ms 1 May 2023 585th commandz0 🇺🇸 554 147 16ms 1 May 2023 585th SniperSmiley 🇺🇸 554 147 10ms 15 Aug 2023 585th fourth-bit 554 147 16ms 2 Jul 2024 585th logvp 554 147 10ms 7 Oct 2024 589th MeWhenI 🇻🇦 554 229 40ms 26 Aug 2023 590th Mabeloid 🇳🇴 553 137 510ms 4 May 2025 591st vhoulbreque 🇫🇷 551 148 10ms 2 Dec 2025 592nd weliveinhell 🇭🇹 551 174 11ms 25 Sep 2023 593rd Shanethegamer 🇺🇸 551 274 201ms 17 May 2023 594th commandz0 🇺🇸 549 138 475ms 1 Sep 2025 595th scpchicken 🇵🇼 547 149 10ms 1 May 2023 595th Vaekor 547 149 10ms 9 Jul 2023 595th Emutis 🇱🇹 547 149 10ms 26 Oct 2025 598th ovs-code 🇩🇪 547 165 3ms 27 Sep 2024 599th acollett89 545 176 9ms 8 Aug 2025 600th jerrandolph 545 288 294ms 2 Nov 2023 601st MeWhenI 🇻🇦 545 325 1,665ms 7 Nov 2025 602nd edsrzf 🇳🇿 544 156 69ms 3 Jul 2025 603rd DialFrost 🇸🇬 543 151 144ms 28 Oct 2024 604th dokutan 541 246 42ms 26 Aug 2024 605th FranklinJiaChen 540 151 10ms 3 Aug 2024 605th Anonymousellama21 540 151 10ms 9 Aug 2024 607th dokutan 538 230 3ms 5 Feb 2025 608th snoozingnewt 🇨🇦 537 145 1,515ms 31 Oct 2025 609th MeWhenI 🇻🇦 537 287 46ms 3 Jul 2023 610th AbhilashaTandon 536 152 10ms 21 Sep 2023 611th snoozingnewt 🇨🇦 536 196 122ms 31 Oct 2025 612th Maximizer02 534 185 8ms 10 Jan 2025 613th AlephSquirrel 533 153 10ms 1 May 2023 613th MaxElf999 533 153 10ms 2 May 2023 613th eiburns 533 153 10ms 5 May 2023 616th AlephSquirrel 530 143 476ms 21 Jan 2024 617th MeWhenI 🇻🇦 530 296 34ms 6 Jun 2023 618th dokutan 525 172 2ms 27 Dec 2025 619th madex 🇩🇪 525 185 1ms 23 Jul 2025 620th Natanaelel 🇸🇪 525 245 126ms 5 May 2023 621st dokutan 524 162 76ms 26 Jan 2026 622nd adoxography 524 183 9ms 22 May 2023 623rd hellwue 522 156 10ms 3 May 2023 623rd hiichbindermax 522 156 10ms 4 May 2023 625th Yewzir 🇧🇪 518 221 2,889ms 9 Feb 2024 626th dokutan 517 119 39ms 21 Apr 2025 627th Mabeloid 🇳🇴 517 188 2ms 2 Oct 2024 628th alemelis 516 158 10ms 5 Oct 2024 628th Andrey135296 516 158 10ms 24 Nov 2024 630th MeWhenI 🇻🇦 515 160 1,022ms 21 May 2023 631st Yewzir 🇧🇪 514 189 2ms 9 Feb 2024 632nd andrewjc2000 513 159 10ms 30 Apr 2025 633rd IISResetMe 511 140 348ms 3 Jan 2026 634th snoozingnewt 🇨🇦 511 147 491ms 27 Nov 2025 635th dokutan 511 220 211ms 29 Jun 2024 636th snoozingnewt 🇨🇦 510 296 213ms 31 Oct 2025 637th mrmena 🇦🇺 507 189 11ms 29 Mar 2024 638th chartung17 506 161 10ms 1 Jan 2024 639th Yewzir 🇧🇪 505 245 3ms 18 Jan 2024 640th tobyLovick 503 162 9ms 29 Nov 2023 First Prev 561–640 of 853 Next Last