The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 8 hours. 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 401st snoozingnewt 🇨🇦 700 190 603ms 31 Oct 2025 402nd stefangimmillaro 700 220 41ms 6 May 2025 403rd CaedenHarper 🇨🇦 700 224 306ms 12 Nov 2025 404th UnderKoen 🇳🇱 700 228 3ms 20 Jan 2025 405th MeWhenI 🇻🇦 699 177 2ms 1 May 2023 406th MeWhenI 🇻🇦 699 194 152ms 1 May 2023 407th MeWhenI 🇻🇦 698 184 455ms 1 May 2023 408th MeWhenI 🇻🇦 695 107 3ms 1 May 2023 409th bizy-coder 695 109 458ms 11 Oct 2024 410th blaztoma 🇱🇹 691 89 38ms 26 Oct 2025 411th AlephSquirrel 689 61 40ms 1 May 2023 412th emgordon154 689 119 130ms 6 Sep 2024 413th snoozingnewt 🇨🇦 689 142 78ms 1 Mar 2026 414th DialFrost 🇸🇬 688 152 5ms 17 Jun 2024 415th adyache 🇺🇸 688 169 8ms 24 May 2023 416th retrohun 687 139 3ms 27 May 2023 417th edsrzf 🇳🇿 687 194 42ms 24 Jan 2025 418th stefangimmillaro 685 198 294ms 13 Oct 2024 419th Shanethegamer 🇺🇸 683 90 34ms 2 May 2023 420th edsrzf 🇳🇿 683 221 217ms 17 Jun 2025 421st MeWhenI 🇻🇦 683 312 7ms 29 Nov 2023 422nd janbehrens 🇩🇪 681 144 385ms 1 May 2023 423rd emgordon154 681 182 4ms 27 Dec 2024 424th zakariamouhid 680 141 10ms 11 May 2023 425th MeWhenI 🇻🇦 680 186 554ms 1 May 2023 426th DialFrost 🇸🇬 679 182 2ms 14 Sep 2024 427th DialFrost 🇸🇬 678 193 3ms 26 Jan 2024 428th jared-hughes 677 190 137ms 11 Sep 2023 429th duckyluuk 🇳🇱 676 146 2,647ms 25 Oct 2024 430th albanian-laundromat 676 183 3ms 7 Jul 2025 431st MeWhenI 🇻🇦 676 197 42ms 4 Sep 2024 432nd bizy-coder 674 121 9ms 6 Nov 2023 432nd 4atj 674 121 10ms 30 Jun 2025 434th retrohun 672 120 2ms 27 May 2023 435th Shanethegamer 🇺🇸 670 112 293ms 9 May 2023 436th clockworknazo 669 135 4ms 23 Jun 2023 437th MeWhenI 🇻🇦 669 168 144ms 4 days ago 438th AshyIsMe 🇦🇺 668 101 34ms 2 May 2023 439th RDShah 668 122 10ms 3 May 2023 439th Yewzir 🇧🇪 668 122 80ms 27 Jan 2024 439th JunkIce 668 122 10ms 24 Jan 2025 442nd elgan65536 🇺🇸 668 226 347ms 26 Oct 2023 443rd 5cw 🇺🇸 665 82 2ms 1 May 2023 444th ZakkkkAttackkkk 🇵🇭 665 146 2ms 12 Nov 2023 445th MeWhenI 🇻🇦 664 197 1ms 11 Oct 2023 446th DialFrost 🇸🇬 657 109 312ms 14 Jun 2024 447th nwellnhof 🇩🇪 657 124 11ms 28 May 2024 448th BambooleanLogic 🇸🇪 657 146 10ms 28 Jun 2023 449th Shanethegamer 🇺🇸 657 174 478ms 1 May 2023 450th emgordon154 657 243 2ms 10 Jun 2025 451st Yax42 🇫🇷 656 148 2ms 14 Oct 2025 452nd SirBogman 🇺🇸 655 82 158ms 28 Aug 2023 453rd dokutan 654 121 1,240ms 21 Apr 2025 454th BlankSpruce 654 175 469ms 28 Aug 2024 455th MeWhenI 🇻🇦 654 177 1ms 1 May 2023 456th janbehrens 🇩🇪 653 160 4ms 2 Jul 2023 457th inventshah 652 125 10ms 3 May 2023 458th Shanethegamer 🇺🇸 652 149 2ms 1 May 2023 459th Yax42 🇫🇷 652 161 118ms 15 Oct 2025 460th Shanethegamer 🇺🇸 651 124 1ms 2 May 2023 461st emgordon154 648 148 11ms 13 Jun 2024 462nd DialFrost 🇸🇬 647 125 4ms 17 Aug 2024 463rd gifti258 646 178 66ms 14 Sep 2023 464th NickTheEASDude 🇺🇸 646 179 1ms 9 Oct 2024 465th DialFrost 🇸🇬 644 128 23ms 1 Mar 2025 466th MeWhenI 🇻🇦 643 151 2ms 25 Aug 2023 467th Mabeloid 🇳🇴 643 180 1ms 21 Sep 2024 468th Seek64 🇩🇪 642 127 10ms 25 Jun 2025 469th CaedenHarper 🇨🇦 641 153 384ms 17 Oct 2025 470th angel-p57 🇯🇵 641 259 1ms 10 Dec 2023 471st stackotter 640 212 133ms 29 May 2023 472nd erikgaal 639 150 9ms 19 Jul 2023 472nd robertvansteen 639 150 10ms 19 Jul 2023 474th Yax42 🇫🇷 639 179 2,877ms 14 Nov 2025 475th msbranicky 638 246 285ms 31 Aug 2023 476th Bulmenisaurus 637 128 10ms 29 Jan 2025 476th ryyyn 🇺🇸 637 128 10ms 6 Feb 2026 478th aditsu 637 155 2,786ms 12 Aug 2025 479th MeWhenI 🇻🇦 636 142 3ms 1 Nov 2023 480th snoozingnewt 🇨🇦 636 182 1ms 31 Oct 2025 First Prev 401–480 of 854 Next Last