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?
Emirp Numbers in all languages in bytes. 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 Bytes Time Submitted 641st rucin93 🇵🇱 823 66 141ms 5 Jan 2025 641st sean-niemann 🇺🇸 823 66 142ms 19 May 2025 643rd MeWhenI 🇻🇦 821 40 47ms 23 Jul 2022 643rd AlephSquirrel 821 40 45ms 31 Jul 2022 645th handisb 821 69 36ms 25 Oct 2019 645th olivermrose 🇺🇸 821 69 37ms 31 Oct 2021 647th StanislavNikolov 821 80 10ms 26 Nov 2017 647th jacklynnepenick 821 80 59ms 16 Aug 2021 647th ejini6969 821 80 12ms 1 Apr 2023 647th TheSecondComing123 821 80 10ms 4 Feb 2026 651st DialFrost 🇸🇬 821 87 1,021ms 26 Feb 2025 652nd MeWhenI 🇻🇦 821 117 66ms 29 Nov 2022 652nd Alex-x90 🇺🇸 821 117 53ms 28 Jan 2023 654th SuperFola 820 147 78ms 8 days ago 655th GalladeGuy 🇺🇸 819 82 2ms 21 May 2020 656th PatrickStephansen 🇿🇦 818 78 10ms 16 Oct 2020 656th Shanethegamer 🇺🇸 818 78 12ms 19 Apr 2022 658th JDiLenarda 🇫🇷 817 91 1,398ms 9 Oct 2020 659th fuzzylojik-golf 🇺🇸 817 101 397ms 31 Aug 2025 659th amazingalek 🇳🇴 817 101 458ms 6 Jan 2026 661st AshyIsMe 🇦🇺 816 35 34ms 4 Aug 2022 662nd Irratix 🇳🇱 816 57 2ms 12 Dec 2021 663rd primo-ppcg 🇹🇭 816 115 131ms 2 May 2022 664th MeWhenI 🇻🇦 814 74 3ms 12 Aug 2024 664th DialFrost 🇸🇬 814 74 4ms 16 Aug 2024 664th Shanethegamer 🇺🇸 814 74 3ms 25 May 2025 664th snoozingnewt 🇨🇦 814 74 3ms 30 Nov 2025 668th KatieLG 🇬🇧 814 77 434ms 15 Jan 2024 668th Babafaba 814 77 476ms 17 Nov 2025 670th Waffle3z 811 81 10ms 7 Sep 2021 670th quimey 811 81 17ms 21 Jun 2023 672nd GoateSo 810 83 2ms 14 Aug 2023 673rd prplz 🇦🇺 810 122 24ms 10 Jul 2021 674th eldritchconundrum 809 70 36ms 31 Oct 2022 675th Yewzir 🇧🇪 809 149 78ms 5 days ago 676th BBoehm 🇩🇪 808 79 10ms 20 Jan 2021 676th DialFrost 🇸🇬 808 79 10ms 14 Nov 2023 678th lifthrasiir 🇰🇷 806 31 2ms 29 Nov 2024 678th GrayJoKing 🇦🇺 806 31 2ms 26 Jun 2025 680th Yewzir 🇧🇪 806 117 363ms 2 Oct 2025 681st scpchicken 🇵🇼 804 59 3ms 5 Feb 2023 682nd weeble 803 75 3ms 16 Dec 2024 683rd prplz 🇦🇺 802 117 144ms 30 Apr 2022 684th SirBogman 🇺🇸 801 41 45ms 29 Oct 2022 684th CaedenHarper 🇨🇦 801 41 48ms 10 days ago 686th Powerroff 801 82 24ms 10 Nov 2024 687th gastropner 801 103 1ms 5 Jan 2021 687th janbehrens 🇩🇪 801 103 376ms 20 Jun 2023 689th dokutan 801 120 65ms 14 Apr 2024 689th snyderek 🇺🇸 801 120 62ms 17 Oct 2024 691st msbranicky 799 135 294ms 8 Sep 2023 692nd annaproxy 798 71 36ms 27 Aug 2022 693rd handisb 798 80 12ms 25 Oct 2019 693rd marcin7Cd 798 80 9ms 5 Oct 2020 693rd stefangimmillaro 798 80 10ms 27 Aug 2022 696th Lydxn 🇨🇦 798 99 2ms 11 Oct 2023 697th dokutan 798 115 40ms 28 Aug 2024 697th MeWhenI 🇻🇦 798 115 40ms 30 Aug 2024 697th pardouin 🇫🇷 798 115 41ms 23 Sep 2024 700th MeWhenI 🇻🇦 797 93 36ms 28 Jun 2022 701st kaascevich 797 95 89ms 21 Jul 2025 702nd m-tkach 🇺🇦 797 124 25ms 18 Jun 2022 703rd dokutan 796 118 134ms 14 Apr 2024 704th janbehrens 🇩🇪 795 70 247ms 28 Nov 2023 705th MeWhenI 🇻🇦 794 84 2,653ms 24 Oct 2024 706th jared-hughes 793 36 33ms 23 Sep 2021 706th 4hg 🇺🇸 793 36 34ms 11 Mar 2025 708th SirBogman 🇺🇸 793 79 406ms 15 Jan 2024 709th GrayJoKing 🇦🇺 793 81 2,261ms 30 Mar 2021 710th dokutan 793 119 369ms 24 Sep 2025 711th yanqui-uxo 792 95 150ms 14 Sep 2018 711th GrayJoKing 🇦🇺 792 95 150ms 16 Mar 2021 711th Natanaelel 🇸🇪 792 95 145ms 11 Sep 2021 711th stackofbears 792 95 151ms 7 Oct 2023 711th HolmDev 792 95 138ms 10 Sep 2025 716th retrohun 790 49 127ms 26 Apr 2019 717th Yewzir 🇧🇪 790 98 120ms 28 Mar 2024 718th DialFrost 🇸🇬 790 100 2ms 18 Nov 2025 719th m-tkach 🇺🇦 790 115 27ms 18 Jan 2024 720th primo-ppcg 🇹🇭 790 176 1,696ms 15 Sep 2025 First Prev 641–720 of 3,207 Next Last