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 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 481st CatsAreFluffy 699 95 52ms 8 Jan 2024 482nd MeWhenI 🇻🇦 699 336 7ms 29 Nov 2023 483rd madex 🇩🇪 698 160 9ms 24 Jul 2025 484th adoxography 697 164 10ms 22 May 2023 484th wh3n3v3r 🇨🇿 697 164 9ms 13 Nov 2024 484th snydej 697 164 9ms 21 Nov 2024 484th kitotch 697 164 10ms 6 days ago 488th jared-hughes 697 190 137ms 11 Sep 2023 489th inventshah 697 191 2ms 11 Jan 2024 489th Yewzir 🇧🇪 697 191 2ms 19 Nov 2025 491st MeWhenI 🇻🇦 695 168 144ms 8 hours ago 492nd olleicua 🇺🇸 694 161 10ms 3 Feb 2024 493rd Shanethegamer 🇺🇸 694 174 478ms 1 May 2023 494th elgan65536 🇺🇸 694 250 347ms 26 Oct 2023 495th AshyIsMe 🇦🇺 693 101 34ms 2 May 2023 496th rozium 693 165 11ms 11 Oct 2024 496th madex 🇩🇪 693 165 10ms 20 Jul 2025 498th SirBogman 🇺🇸 692 93 139ms 28 Aug 2023 499th CaedenHarper 🇨🇦 692 153 384ms 17 Oct 2025 500th BlankSpruce 690 175 474ms 28 Aug 2024 501st helbling 🇨🇭 689 162 10ms 24 Sep 2024 501st a6166231 🇨🇳 689 162 11ms 16 May 2025 503rd msbranicky 689 166 10ms 5 Aug 2023 504th Yax42 🇫🇷 688 185 118ms 15 Oct 2025 505th guilhem-roy 🇫🇷 685 167 10ms 29 Jun 2023 505th fkantelberg 685 167 10ms 25 Jul 2023 505th HumanoidCPU 685 167 10ms 10 Jan 2026 508th pardouin 🇫🇷 684 100 35ms 23 Jul 2025 509th croc54 680 168 10ms 2 Dec 2024 510th MeWhenI 🇻🇦 680 195 7ms 9 May 2024 511th adamnielson42 🇺🇸 678 116 3ms 10 Jan 2024 512th DialFrost 🇸🇬 677 101 37ms 2 Jun 2024 513th AlephSquirrel 677 143 476ms 21 Jan 2024 514th zakariamouhid 677 165 10ms 11 May 2023 515th snoozingnewt 🇨🇦 676 153 79ms 25 days ago 516th ehulinsky 🇺🇸 676 169 10ms 16 May 2023 516th briankuder 676 169 9ms 20 Jun 2023 516th jmerle 🇳🇱 676 169 10ms 11 Jul 2023 519th Shanethegamer 🇺🇸 675 149 2ms 1 May 2023 520th MeWhenI 🇻🇦 675 197 2ms 11 Oct 2023 521st Yax42 🇫🇷 674 179 2,877ms 14 Nov 2025 522nd janbehrens 🇩🇪 672 160 4ms 2 Jul 2023 523rd OllieBoyne 🇬🇧 672 170 10ms 1 May 2023 523rd Chimplement 672 170 10ms 13 Dec 2023 525th SirBogman 🇺🇸 671 102 34ms 28 Aug 2023 526th Shanethegamer 🇺🇸 671 124 1ms 2 May 2023 527th ZakkkkAttackkkk 🇵🇭 671 150 2ms 12 Nov 2023 528th Shanethegamer 🇺🇸 669 114 255ms 12 May 2023 529th TaserTheFox 🇺🇸 669 171 10ms 1 May 2023 530th DialFrost 🇸🇬 667 125 4ms 17 Aug 2024 531st emgordon154 667 243 2ms 10 Jun 2025 532nd MeWhenI 🇻🇦 666 151 2ms 25 Aug 2023 532nd Yax42 🇫🇷 666 151 2ms 3 days ago 534th prestosilver 🇺🇸 666 196 485ms 24 days ago 535th niklv 🇷🇺 665 168 13ms 14 May 2023 536th CedricGebistorf 665 172 11ms 3 May 2023 536th luuumine 🇫🇷 665 172 9ms 9 Nov 2025 536th vhoulbreque 🇫🇷 665 172 10ms 2 Dec 2025 539th Shanethegamer 🇺🇸 664 103 35ms 1 May 2023 540th Vaekor 661 173 10ms 9 Jul 2023 541st yzhs 🇩🇪 657 174 10ms 22 Jun 2023 542nd edsrzf 🇳🇿 655 135 2ms 16 Jun 2025 543rd msbranicky 655 214 2ms 17 Aug 2023 544th albanian-laundromat 654 148 469ms 4 Aug 2025 545th MeWhenI 🇻🇦 654 157 2,766ms 2 Dec 2024 545th aditsu 654 157 2,821ms 12 Aug 2025 547th MeWhenI 🇻🇦 653 160 1,022ms 21 May 2023 548th FranklinJiaChen 653 175 10ms 3 Aug 2024 548th Matter1024 🇮🇳 653 175 10ms 17 Feb 2026 550th angel-p57 🇯🇵 652 259 1ms 10 Dec 2023 551st Aurel300 🇨🇭 652 266 235ms 21 Jul 2024 552nd AbhilashaTandon 650 176 10ms 21 Sep 2023 553rd msbranicky 650 267 191ms 1 Oct 2023 554th emgordon154 649 172 12ms 13 Jun 2024 555th snoozingnewt 🇨🇦 649 196 122ms 31 Oct 2025 556th msbranicky 649 246 285ms 31 Aug 2023 557th billings7 🇬🇧 646 164 396ms 20 May 2024 558th eiburns 646 177 10ms 5 May 2023 559th MeWhenI 🇻🇦 646 187 453ms 1 May 2023 560th janAkali 🇷🇺 646 202 433ms 21 Feb 2026 First Prev 481–560 of 857 Next Last