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?
Abundant Numbers 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 475th LoLoLucky 849 55 11ms 7 Dec 2020 475th nwellnhof 🇩🇪 849 55 11ms 10 Jan 2021 475th didion0 🇺🇸 849 55 10ms 9 Mar 2021 475th ScottHamper 849 55 10ms 26 May 2021 475th itsh01 849 55 11ms 10 Aug 2021 475th jakzo 849 55 11ms 5 Sep 2021 475th nathanadams 🇳🇿 849 55 11ms 10 Sep 2021 475th janlelis 849 55 10ms 11 Nov 2021 475th igmcdowell 849 55 11ms 16 Nov 2021 475th emgordon154 849 55 13ms 29 Nov 2021 475th KrausRaus 🇺🇸 849 55 11ms 7 Dec 2021 475th KingSkyrock 🇺🇸 849 55 11ms 12 Feb 2022 475th ovs-code 🇩🇪 849 55 11ms 16 Dec 2022 475th tayloia 🇬🇧 849 55 22ms 12 Jan 2023 475th thisishowmymindworks 🇳🇴 849 55 10ms 11 May 2023 475th biocommando 🇫🇮 849 55 10ms 16 Aug 2023 475th helbling 🇨🇭 849 55 13ms 29 Feb 2024 475th Natanaelel 🇸🇪 849 55 12ms 12 Mar 2024 475th denis-jasselette 849 55 11ms 17 Oct 2025 475th attila8192 849 55 10ms 8 Feb 2026 501st RussellEmerine 849 67 124ms 2 Jan 2020 501st hymanimy 849 67 129ms 19 Aug 2021 501st MeWhenI 🇻🇦 849 67 130ms 12 Aug 2022 501st PPKFS 849 67 122ms 10 Dec 2022 501st arutonee1 849 67 112ms 15 Dec 2025 506th nipzu 849 78 133ms 13 Jan 2022 506th frozolotl 849 78 141ms 19 Jan 2022 506th GrayJoKing 🇦🇺 849 78 134ms 4 Apr 2022 506th ian-h-chamberlain 🇺🇸 849 78 125ms 21 Nov 2022 506th klixel 🇨🇦 849 78 133ms 5 Dec 2022 506th snobee 🇨🇦 849 78 133ms 10 Dec 2022 506th msbranicky 849 78 131ms 1 Oct 2023 506th ludwigschlame 🇩🇪 849 78 127ms 24 Sep 2024 506th elituf 849 78 134ms 4 Jan 2025 506th TannerJ07 🇺🇸 849 78 131ms 5 Apr 2025 506th lynn 849 78 131ms 6 Nov 2025 506th acotis 849 78 138ms 23 Feb 2026 506th roelderickx 849 78 130ms 3 days ago 519th GrayJoKing 🇦🇺 848 64 135ms 31 May 2022 519th albanian-laundromat 848 64 135ms 11 Nov 2025 521st MeWhenI 🇻🇦 846 48 7ms 13 Aug 2024 521st DialFrost 🇸🇬 846 48 7ms 13 Aug 2024 521st Shanethegamer 🇺🇸 846 48 7ms 15 Aug 2024 521st ovs-code 🇩🇪 846 48 7ms 20 Aug 2024 521st lynn 846 48 7ms 15 Dec 2024 526th GrayJoKing 🇦🇺 846 56 6ms 9 Apr 2021 527th MeWhenI 🇻🇦 845 41 2ms 6 Aug 2021 528th rak1507 🇬🇧 845 57 9ms 22 Oct 2020 528th KatieLG 🇬🇧 845 57 12ms 8 Nov 2020 528th Shanethegamer 🇺🇸 845 57 11ms 22 May 2021 528th gilufin 845 57 12ms 25 May 2021 528th HETHAT 🇩🇿 845 57 12ms 17 Aug 2021 528th MatthiasDurivet 845 57 11ms 14 Oct 2021 528th RobbeSneyders 845 57 11ms 15 Oct 2021 528th Irratix 🇳🇱 845 57 12ms 7 May 2022 528th btjones0 845 57 18ms 15 Jul 2022 528th Fishron 845 57 11ms 29 Nov 2022 528th DialFrost 🇸🇬 845 57 11ms 9 Feb 2023 528th ndren 845 57 12ms 3 Oct 2023 528th abc7-12 845 57 10ms 6 May 2024 528th tri1212 🇻🇳 845 57 11ms 30 Jun 2024 528th b-illy 🇬🇧 845 57 13ms 9 Aug 2024 528th emgordon154 845 57 11ms 12 Apr 2025 528th CaedenHarper 🇨🇦 845 57 11ms 1 Aug 2025 528th qpwoeirut 845 57 12ms 2 Oct 2025 528th albanian-laundromat 845 57 12ms 7 Oct 2025 528th anter69 🇭🇺 845 57 10ms 8 Dec 2025 528th Flekay 🇩🇪 845 57 18ms 15 Feb 2026 528th plcc0 845 57 20ms 26 days ago 528th dokutan 845 57 12ms 21 days ago 528th yujh-yujh 🇬🇸 845 57 11ms 15 days ago 552nd JohandeRuiter 🇳🇱 845 65 147ms 27 Jan 2024 553rd DialFrost 🇸🇬 843 65 28ms 16 Dec 2024 554th pardouin 🇫🇷 841 41 468ms 15 Sep 2024 555th primo-ppcg 🇹🇭 841 51 126ms 18 Nov 2019 556th adyache 🇺🇸 840 49 4ms 31 May 2023 557th MeWhenI 🇻🇦 840 76 431ms 5 Mar 2022 558th anter69 🇭🇺 839 45 1,352ms 23 Feb 2023 558th edsrzf 🇳🇿 839 45 1,329ms 21 Jan 2025 560th syntax-rules 839 75 26ms 15 May 2023 First Prev 481–560 of 4,401 Next Last