The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 5 days. Why not try and solve them ahead of time?
Emirp 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 720th Davr1 🇨🇿 740 76 10ms 15 Oct 2023 720th ovs-code 🇩🇪 740 76 10ms 17 Nov 2024 723rd GrayJoKing 🇦🇺 739 54 36ms 24 Nov 2021 723rd emgordon154 739 54 36ms 26 Jul 2024 725th ian-h-chamberlain 🇺🇸 739 107 39ms 20 Oct 2025 726th RustemB 🇷🇺 738 50 90ms 3 Jan 2021 726th ovs-code 🇩🇪 738 50 155ms 8 May 2024 728th ovs-code 🇩🇪 737 68 442ms 16 Jan 2024 729th gnuvince 735 34 2ms 28 Jun 2025 730th AlephSquirrel 734 40 45ms 31 Jul 2022 731st GrayJoKing 🇦🇺 732 78 3ms 26 Jul 2023 732nd itsh01 731 77 11ms 23 Aug 2021 733rd davitf 730 74 11ms 19 Nov 2018 733rd ydevor 🇮🇱 730 74 10ms 26 Nov 2020 733rd itsjustfreekie 730 74 12ms 19 Sep 2021 733rd ZakkkkAttackkkk 🇵🇭 730 74 12ms 26 Dec 2021 733rd domingues 🇵🇹 730 74 9ms 10 Aug 2022 733rd jakobkordez 🇸🇮 730 74 56ms 31 Oct 2022 733rd scpchicken 🇵🇼 730 74 10ms 17 Jan 2023 733rd aksyristos 730 74 11ms 26 Jan 2023 741st dokutan 730 93 369ms 24 Sep 2025 742nd msbranicky 729 214 10ms 29 Aug 2023 743rd Yewzir 🇧🇪 728 77 378ms 8 May 2023 743rd janbehrens 🇩🇪 728 77 376ms 20 Jun 2023 745th GrayJoKing 🇦🇺 727 73 4ms 16 Aug 2023 745th edsrzf 🇳🇿 727 73 4ms 30 Nov 2025 747th annaproxy 726 91 130ms 5 Feb 2022 748th sisyphus-ppcg 🇦🇺 725 55 38ms 15 Jun 2021 748th Yewzir 🇧🇪 725 55 37ms 7 Feb 2024 750th inventshah 725 62 2,718ms 24 Oct 2024 750th DialFrost 🇸🇬 725 62 3,318ms 25 Dec 2024 752nd jared-hughes 725 89 2ms 5 Jul 2024 753rd MeWhenI 🇻🇦 725 109 2ms 10 Oct 2023 754th emgordon154 723 59 1,376ms 26 Jul 2024 755th marcin7Cd 723 97 5ms 6 Feb 2021 756th DialFrost 🇸🇬 722 94 474ms 1 Jan 2026 757th FlorianCassayre 🇫🇷 721 75 13ms 18 Sep 2023 758th marcin7Cd 721 78 9ms 5 Oct 2020 758th PatrickStephansen 🇿🇦 721 78 10ms 16 Oct 2020 758th Shanethegamer 🇺🇸 721 78 12ms 19 Apr 2022 761st dokutan 721 90 100ms 12 Dec 2025 762nd jmerle 🇳🇱 721 134 7ms 4 Jul 2023 763rd DialFrost 🇸🇬 720 79 5ms 16 Dec 2025 764th rucin93 🇵🇱 718 110 12ms 18 Nov 2025 765th SirBogman 🇺🇸 716 41 45ms 29 Oct 2022 765th CaedenHarper 🇨🇦 716 41 48ms 8 days ago 767th commandz0 🇺🇸 716 70 432ms 15 Jan 2024 768th Steffan153 🇫🇮 716 135 7ms 12 Mar 2023 768th annaproxy 716 135 8ms 12 Mar 2023 768th Shanethegamer 🇺🇸 716 135 7ms 12 Mar 2023 768th lynn 716 135 7ms 13 Mar 2023 768th JayXon 🇺🇸 716 135 7ms 13 Mar 2023 768th ovs-code 🇩🇪 716 135 7ms 13 Mar 2023 768th Lydxn 🇨🇦 716 135 7ms 13 Mar 2023 768th dokutan 716 135 7ms 1 Apr 2023 768th MeWhenI 🇻🇦 716 135 7ms 23 Nov 2023 768th Yewzir 🇧🇪 716 135 7ms 6 Mar 2024 768th KatieLG 🇬🇧 716 135 7ms 31 Jul 2024 768th snoozingnewt 🇨🇦 716 135 7ms 5 Oct 2025 768th JOrE20 716 135 7ms 15 Dec 2025 781st nickspoons 🇳🇿 714 40 33ms 1 Aug 2022 782nd SirBogman 🇺🇸 713 49 230ms 8 Jan 2024 783rd marshallward 🇺🇸 713 114 52ms 2 Oct 2020 784th edsrzf 🇳🇿 712 58 1,224ms 8 Sep 2025 785th lynn 712 68 1,233ms 27 May 2021 786th prplz 🇦🇺 712 78 124ms 10 Jul 2021 786th MeWhenI 🇻🇦 712 78 131ms 4 Jan 2022 786th GrayJoKing 🇦🇺 712 78 125ms 9 Apr 2022 789th BBoehm 🇩🇪 712 79 10ms 20 Jan 2021 789th DialFrost 🇸🇬 712 79 10ms 14 Nov 2023 791st lynn 712 100 130ms 7 Jul 2024 791st sean-niemann 🇺🇸 712 100 133ms 6 Jun 2025 793rd Bubbler-4 711 55 63ms 13 Sep 2023 793rd DialFrost 🇸🇬 711 55 64ms 8 Apr 2025 795th Irratix 🇳🇱 711 60 1,311ms 25 Mar 2021 796th GrayJoKing 🇦🇺 711 74 139ms 10 Aug 2024 797th Nic0M 711 76 10ms 13 Aug 2023 797th vgamula 🇺🇦 711 76 13ms 10 Jul 2024 797th Emutis 🇱🇹 711 76 10ms 10 Nov 2025 797th Lv0Sys 🇵🇱 711 76 10ms 20 Feb 2026 First Prev 721–800 of 3,185 Next Last