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 801st meenie 278 246 35ms 1 May 2023 802nd dokutan 272 377 2,762ms 25 Oct 2024 803rd MarkE0 270 283 299ms 28 Apr 2024 804th eli-siegel 270 591 280ms 23 Jun 2023 805th PYRiTEmonark 268 426 11ms 11 Sep 2023 806th dokutan 267 493 591ms 7 Nov 2025 807th dokutan 264 371 2ms 30 Jul 2024 808th Apataras 261 519 444ms 29 Jun 2025 809th MeWhenI 🇻🇦 259 438 14ms 1 May 2023 810th dokutan 248 226 43ms 17 Jun 2024 811th dokutan 247 336 3ms 28 Jun 2025 812th dokutan 241 529 120ms 28 Mar 2025 813th dokutan 239 245 3ms 14 Nov 2024 814th dokutan 223 474 377ms 16 Jul 2024 815th dokutan 222 375 6ms 13 Aug 2024 816th MeWhenI 🇻🇦 215 326 34ms 1 May 2023 817th TerenceTux 215 467 2ms 22 May 2023 818th harperse 214 356 276ms 4 May 2023 819th MeWhenI 🇻🇦 212 631 5ms 1 May 2023 820th dokutan 202 529 154ms 22 Oct 2024 821st MeWhenI 🇻🇦 201 331 50ms 1 May 2023 822nd AidanWalter 201 570 10ms 3 Jan 2025 823rd kasarino 195 516 2ms 26 Feb 2026 824th muser-logiccpu 🇺🇦 191 600 11ms 25 Jul 2025 825th dokutan 186 450 927ms 29 Aug 2025 826th KatieLG 🇬🇧 173 1,005 322ms 15 Sep 2024 827th dokutan 169 451 226ms 11 Oct 2024 828th dokutan 163 757 16ms 6 Jan 2025 829th holzay 158 723 10ms 6 Aug 2024 830th MeWhenI 🇻🇦 142 452 125ms 1 May 2023 831st dokutan 139 996 704ms 23 Sep 2024 832nd dokutan 128 616 3ms 30 Dec 2023 833rd KatieLG 🇬🇧 113 767 280ms 15 Sep 2024 834th BKGSr2 109 1,024 9ms 25 Sep 2023 835th Msleizak 🇫🇷 102 751 311ms 22 Aug 2025 836th KatieLG 🇬🇧 100 1,038 87ms 15 Sep 2024 837th KatieLG 🇬🇧 97 1,260 3ms 15 Sep 2024 838th PierceZ 82 1,658 438ms 29 Nov 2023 839th alecdavidson 79 1,709 409ms 8 Dec 2023 840th MeWhenI 🇻🇦 41 4,114 2ms 1 May 2023 841st darrenks 🇺🇸 0 29 36ms 18 Apr 2025 842nd plcc0 0 32 46ms 15 Feb 2026 843rd Natanaelel 🇸🇪 0 39 53ms 27 May 2025 844th aditsu 0 50 101ms 12 Aug 2025 845th ovs-code 🇩🇪 0 76 6ms 23 Sep 2025 846th plcc0 0 80 668ms 23 Mar 2025 847th themoonisacheese 0 82 610ms 17 Mar 2025 848th namelessiw 0 93 165ms 21 Oct 2025 849th AlephSquirrel 0 94 5ms 18 Dec 2025 850th ovs-code 🇩🇪 0 98 3ms 25 Jul 2025 851st maweowo 🇩🇪 0 100 5ms 8 Oct 2025 852nd ovs-code 🇩🇪 0 111 13ms 17 Jun 2025 853rd dokutan 0 156 75ms 13 days ago 854th KatieLG 🇬🇧 0 161 4ms 19 May 2025 855th edsrzf 🇳🇿 0 202 208ms 24 May 2025 856th Matter1024 🇮🇳 0 212 2ms 11 hours ago 857th dokutan 0 281 3ms 23 Sep 2025 858th dokutan 0 354 8ms 11 Jan 2026 First Prev 801–858 of 858