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 480th r-schmidtke 635 151 9ms 26 Apr 2024 482nd 5cw 🇺🇸 632 129 10ms 2 Aug 2024 483rd tomh1012 632 155 438ms 3 hours ago 484th greenstuartj 631 107 33ms 24 Jul 2023 485th albanian-laundromat 631 201 41ms 7 Nov 2025 486th Shanethegamer 🇺🇸 628 114 255ms 12 May 2023 487th MeWhenI 🇻🇦 628 157 2,766ms 2 Dec 2024 488th bzijlema 🇳🇱 627 130 10ms 23 Jul 2025 489th MeWhenI 🇻🇦 626 120 251ms 26 Aug 2023 490th JRaspass 🇬🇧 624 96 4ms 17 May 2023 491st MeWhenI 🇻🇦 623 231 1,415ms 1 May 2023 492nd RaBa21 🇭🇺 622 131 10ms 19 Jul 2025 493rd JunkIce 621 122 441ms 24 Jan 2025 494th snoozingnewt 🇨🇦 620 253 292ms 31 Oct 2025 495th Sora1248 🇩🇪 619 157 2ms 21 May 2023 496th prplz 🇦🇺 617 132 10ms 12 May 2023 496th uttumuttu 🇫🇮 617 132 10ms 22 Dec 2023 496th edsrzf 🇳🇿 617 132 10ms 11 Dec 2025 499th rucin93 🇵🇱 617 133 152ms 21 Feb 2025 500th edsrzf 🇳🇿 615 147 3ms 22 Nov 2025 501st annaproxy 613 133 11ms 1 May 2023 502nd emgordon154 613 246 182ms 14 Mar 2025 503rd MeWhenI 🇻🇦 612 187 453ms 1 May 2023 504th janbehrens 🇩🇪 611 123 507ms 1 May 2023 505th iczelia 🇩🇪 611 157 12ms 23 Oct 2025 506th BlankSpruce 611 159 1ms 26 Aug 2024 507th DialFrost 🇸🇬 609 101 37ms 2 Jun 2024 508th bricknellj 608 134 9ms 9 Jul 2024 508th blaztoma 🇱🇹 608 134 10ms 31 Jan 2026 510th KrausRaus 🇺🇸 608 215 2ms 11 Oct 2023 511th Yewzir 🇧🇪 607 158 9ms 11 Feb 2024 511th alexsave 607 158 10ms 16 Jan 2026 513th MeWhenI 🇻🇦 607 425 1,462ms 10 Feb 2025 514th billings7 🇬🇧 605 162 396ms 20 May 2024 515th SirBogman 🇺🇸 603 102 34ms 28 Aug 2023 516th GolfingSuccess 🇬🇷 603 161 1ms 1 May 2023 517th Bmrl7 599 136 11ms 20 Feb 2024 518th MeWhenI 🇻🇦 597 120 281ms 1 May 2023 519th Yewzir 🇧🇪 596 263 295ms 5 Jan 2024 520th xdaniel-lim 595 137 9ms 27 Jan 2025 520th Mabeloid 🇳🇴 595 137 10ms 4 May 2025 520th aksyristos 595 137 10ms 3 hours ago 523rd emgordon154 595 166 8ms 7 Jan 2025 524th edsrzf 🇳🇿 594 111 2ms 16 Jun 2025 525th ravnskjaer 🇩🇰 594 224 458ms 15 Dec 2025 526th snoozingnewt 🇨🇦 593 279 119ms 8 Oct 2025 527th CaedenHarper 🇨🇦 592 128 498ms 11 Aug 2025 528th didion0 🇺🇸 592 162 9ms 2 May 2023 528th eranws 592 162 10ms 23 Dec 2024 528th a6166231 🇨🇳 592 162 11ms 16 May 2025 531st jared-hughes 592 164 2ms 7 Sep 2023 532nd zbreit 🇺🇸 591 138 17ms 5 May 2023 532nd StefanHabel 🇨🇦 591 138 10ms 13 Aug 2023 532nd markusgraube 591 138 9ms 26 Mar 2024 535th postie77 590 166 391ms 11 Jul 2023 536th 5pyr 590 196 1ms 16 May 2023 536th Sciman101 590 196 1ms 16 May 2023 538th Shanethegamer 🇺🇸 589 166 100ms 13 May 2023 539th KatieLG 🇬🇧 588 163 10ms 1 May 2023 540th Yewzir 🇧🇪 588 205 11ms 30 Dec 2024 541st DialFrost 🇸🇬 587 129 527ms 17 Jan 2024 542nd zhaohm14 586 139 10ms 23 Jul 2025 542nd YAJUE114514 586 139 9ms 14 Dec 2025 544th MeWhenI 🇻🇦 585 218 3ms 24 Jul 2023 545th sanscheese 582 103 4ms 21 Jul 2023 546th ahmetdemirag 🇨🇾 582 140 10ms 30 Oct 2024 547th yzhs 🇩🇪 582 221 129ms 25 Jun 2023 548th MeWhenI 🇻🇦 578 131 446ms 24 May 2024 549th rschwa6308 🇺🇸 578 141 16ms 5 May 2023 549th MeWhenI 🇻🇦 578 141 11ms 26 Feb 2025 551st MeWhenI 🇻🇦 578 181 5ms 28 May 2023 552nd msbranicky 578 214 2ms 17 Aug 2023 553rd GolfingSuccess 🇬🇷 574 142 10ms 1 May 2023 553rd janbehrens 🇩🇪 574 142 10ms 1 May 2023 553rd MichalMarsalek 🇨🇿 574 142 10ms 1 May 2023 553rd doktoren 574 142 10ms 7 Dec 2023 553rd KasperKivimaeki 🇫🇮 574 142 9ms 2 Nov 2025 558th The-Wolfson 574 288 144ms 9 Feb 2025 559th adyache 🇺🇸 573 171 399ms 4 May 2023 560th guilhem-roy 🇫🇷 570 143 10ms 29 Jun 2023 First Prev 481–560 of 853 Next Last