The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 3 days. Why not try and solve them ahead of time?
Sierpiński Triangle 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 janbehrens 🇩🇪 738 73 2ms 29 Nov 2023 482nd stefangimmillaro 738 94 414ms 6 Oct 2025 483rd jared-hughes 737 75 72ms 19 Jul 2022 483rd rucin93 🇵🇱 737 75 52ms 12 Oct 2025 485th cure-honey 🇯🇵 737 131 281ms 9 Jul 2021 486th rak1507 🇬🇧 736 72 11ms 10 Mar 2021 486th AlephSquirrel 736 72 10ms 24 Jan 2023 486th wh3n3v3r 🇨🇿 736 72 10ms 13 Nov 2024 489th janbehrens 🇩🇪 734 64 5ms 28 Nov 2023 490th iznax 734 85 360ms 21 Nov 2021 491st janbehrens 🇩🇪 734 94 485ms 28 Nov 2023 492nd MeepMoop 733 86 2ms 9 Apr 2025 493rd dunkyl 732 87 1,390ms 16 Nov 2023 494th Shanethegamer 🇺🇸 731 73 2ms 11 Sep 2022 495th sean-niemann 🇺🇸 730 58 255ms 1 Jan 2024 496th MeWhenI 🇻🇦 730 172 1,463ms 9 Feb 2025 497th itsh01 728 63 10ms 4 Sep 2022 497th Maznek 728 63 12ms 25 Jun 2023 499th Shanethegamer 🇺🇸 728 67 427ms 16 Jan 2024 499th bizy-coder 728 67 438ms 17 Jan 2024 499th MeWhenI 🇻🇦 728 67 426ms 17 Jan 2024 499th KatieLG 🇬🇧 728 67 375ms 28 Oct 2024 503rd MeWhenI 🇻🇦 728 78 164ms 17 Nov 2022 504th retrohun 727 76 5ms 25 Sep 2022 505th vishwathg 726 73 10ms 3 Apr 2023 505th janbehrens 🇩🇪 726 73 9ms 28 Nov 2023 505th dirckvdende 726 73 10ms 18 Jul 2025 508th timvermeulen 726 103 141ms 5 Jan 2020 508th snobee 🇨🇦 726 103 161ms 12 Dec 2022 510th MeWhenI 🇻🇦 725 86 379ms 17 Nov 2022 511th Yewzir 🇧🇪 724 101 8ms 24 Dec 2023 512th emgordon154 723 61 1,366ms 3 Jun 2025 513th lynn 722 82 9ms 8 Dec 2021 514th dpatterbee 721 134 281ms 23 Nov 2020 515th MeWhenI 🇻🇦 720 160 1ms 21 Apr 2024 516th Irratix 🇳🇱 719 79 157ms 26 Dec 2020 517th vonagam 718 62 37ms 9 Nov 2017 517th Waffle3z 718 62 36ms 22 Jan 2021 517th yzhs 🇩🇪 718 62 35ms 20 Jul 2022 520th AlephSquirrel 718 75 2ms 25 May 2020 520th NewDefectus 🇮🇱 718 75 2ms 9 Nov 2021 520th lynn 718 75 2ms 30 Nov 2021 520th MeWhenI 🇻🇦 718 75 1ms 17 Nov 2022 520th BlankSpruce 718 75 2ms 8 Aug 2024 525th tomtheisen 🇺🇸 717 64 13ms 12 Oct 2020 525th Attero 🇸🇪 717 64 11ms 21 Oct 2020 525th NewDefectus 🇮🇱 717 64 10ms 9 Nov 2021 525th Argeento 🇵🇱 717 64 12ms 28 Dec 2021 525th MeWhenI 🇻🇦 717 64 10ms 17 Nov 2022 525th GrayJoKing 🇦🇺 717 64 10ms 24 Jan 2023 525th Yax42 🇫🇷 717 64 8ms 13 Sep 2025 532nd stefangimmillaro 717 91 116ms 20 Oct 2022 533rd SirBogman 🇺🇸 717 93 113ms 17 Jun 2020 534th JOrE20 717 215 7ms 30 Nov 2025 535th MeWhenI 🇻🇦 716 73 149ms 3 Aug 2024 536th daedals 716 74 10ms 14 May 2019 536th petar-donchev 716 74 9ms 8 Sep 2019 536th jared-hughes 716 74 9ms 10 Sep 2022 536th betaveros 716 74 10ms 31 Dec 2022 536th stefangimmillaro 716 74 11ms 11 Mar 2023 536th BREMAUCY 🇫🇷 716 74 10ms 1 Nov 2025 536th blaztoma 🇱🇹 716 74 10ms 6 days ago 543rd Shanethegamer 🇺🇸 716 98 403ms 13 Dec 2022 544th duckyluuk 🇳🇱 715 161 2ms 29 Jan 2026 545th bstrat 714 42 2ms 19 Jun 2024 545th emgordon154 714 42 2ms 24 Feb 2026 547th nullie 712 105 142ms 12 Mar 2025 548th janbehrens 🇩🇪 711 350 11ms 2 Aug 2023 549th juliansiebert 🇩🇪 710 65 286ms 1 Aug 2022 549th IISResetMe 710 65 268ms 7 Apr 2025 551st prplz 🇦🇺 709 76 1ms 26 Apr 2019 551st Attero 🇸🇪 709 76 2ms 23 May 2020 551st Alex-x90 🇺🇸 709 76 2ms 24 Jan 2023 551st JohandeRuiter 🇳🇱 709 76 2ms 30 Nov 2023 555th janbehrens 🇩🇪 709 78 4ms 28 Nov 2023 556th emgordon154 709 177 1,439ms 11 Jul 2025 557th GalladeGuy 🇺🇸 708 89 1ms 12 Apr 2019 557th Waffle3z 708 89 2ms 24 Oct 2020 559th janbehrens 🇩🇪 707 63 36ms 30 May 2022 559th tatzyr 🇯🇵 707 63 36ms 25 Nov 2024 First Prev 481–560 of 2,084 Next Last