The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 2 days. Why not try and solve them ahead of time?
Day of Week 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 638th sean-niemann 🇺🇸 840 48 2ms 21 Apr 2023 638th sisyphus-ppcg 🇦🇺 840 48 2ms 24 Apr 2023 638th Lydxn 🇨🇦 840 48 2ms 2 May 2023 638th MeWhenI 🇻🇦 840 48 2ms 26 May 2023 638th ovs-code 🇩🇪 840 48 3ms 15 Aug 2023 638th retrohun 840 48 2ms 29 Jun 2024 638th DialFrost 🇸🇬 840 48 2ms 22 Dec 2024 638th Salutations45 840 48 2ms 7 Oct 2025 638th edsrzf 🇳🇿 840 48 3ms 5 Jan 2026 650th keelimeguy 🇺🇸 840 78 15ms 16 Nov 2023 650th gallium-gonzollium 840 78 25ms 25 Aug 2024 652nd sean-niemann 🇺🇸 840 161 4ms 21 Apr 2025 652nd GolfingSuccess 🇬🇷 840 161 4ms 20 Nov 2025 654th MeWhenI 🇻🇦 839 53 9ms 28 Sep 2024 655th emgordon154 838 135 136ms 29 Dec 2025 656th Yewzir 🇧🇪 837 71 382ms 19 Nov 2023 657th CLOStrophobic 🇮🇹 836 89 8ms 6 May 2025 658th LogicalJoe 836 102 2ms 1 May 2023 659th Shanethegamer 🇺🇸 835 42 76ms 25 Mar 2024 659th MeWhenI 🇻🇦 835 42 75ms 2 Aug 2024 659th JOrE20 835 42 74ms 26 Feb 2026 662nd Lydxn 🇨🇦 835 115 12ms 17 Apr 2023 663rd Steffan153 🇫🇮 834 162 4ms 29 Jan 2024 664th dvargas46 🇺🇸 833 98 103ms 18 Apr 2023 665th 0xjac 🇨🇭 833 128 294ms 11 Jun 2025 666th SirBogman 🇺🇸 832 57 125ms 23 Jan 2024 667th PowershellKnut 🇳🇴 832 81 66ms 7 Jan 2024 668th DialFrost 🇸🇬 832 136 119ms 29 Dec 2025 669th edsrzf 🇳🇿 832 191 32ms 13 Feb 2026 670th jipsong 🇩🇪 831 65 2,635ms 9 Jun 2025 671st Yewzir 🇧🇪 830 70 10ms 14 Dec 2023 671st emgordon154 830 70 11ms 6 Dec 2024 673rd JarrodCope 829 71 381ms 19 Apr 2024 674th GolfingSuccess 🇬🇷 829 124 440ms 30 Dec 2024 675th Yewzir 🇧🇪 828 116 145ms 30 Apr 2023 676th jipsong 🇩🇪 827 101 3ms 9 Feb 2025 676th snoozingnewt 🇨🇦 827 101 4ms 12 Dec 2025 678th xsot 🇸🇬 824 54 9ms 28 Sep 2024 679th primo-ppcg 🇹🇭 824 206 43ms 26 Apr 2025 679th marshallward 🇺🇸 824 206 41ms 7 May 2025 681st KrausRaus 🇺🇸 823 53 6ms 21 Apr 2023 681st Shanethegamer 🇺🇸 823 53 6ms 2 Jul 2023 681st Kokusui 🇯🇵 823 53 6ms 4 Oct 2024 681st Salutations45 823 53 5ms 21 Nov 2024 685th GrayJoKing 🇦🇺 823 137 17ms 3 May 2023 686th fuzzylojik-golf 🇺🇸 822 105 9ms 14 Oct 2023 686th jkelly467 822 105 10ms 8 Jan 2026 688th MeWhenI 🇻🇦 820 207 40ms 29 Apr 2025 689th AtengChen 819 80 23ms 31 Aug 2024 690th mtirado1 819 102 4ms 17 Apr 2023 690th NickTheEASDude 🇺🇸 819 102 3ms 27 Mar 2024 692nd MeWhenI 🇻🇦 819 165 26ms 20 Dec 2023 693rd Steffan153 🇫🇮 819 194 32ms 12 Feb 2026 694th JayXon 🇺🇸 819 307 1,694ms 22 Apr 2024 695th emgordon154 818 328 1,484ms 6 Nov 2025 696th sisyphus-ppcg 🇦🇺 817 100 8ms 21 Apr 2023 697th Shanethegamer 🇺🇸 816 89 197ms 24 May 2025 697th sean-niemann 🇺🇸 816 89 211ms 25 May 2025 697th MeWhenI 🇻🇦 816 89 177ms 2 days ago 700th Yewzir 🇧🇪 816 126 443ms 6 May 2024 701st MeWhenI 🇻🇦 816 196 919ms 27 Feb 2026 702nd sean-niemann 🇺🇸 816 199 5ms 4 Jul 2025 703rd Ripick 814 73 391ms 11 Jul 2024 704th KatieLG 🇬🇧 814 106 9ms 24 Apr 2023 705th dokutan 814 151 601ms 7 Nov 2025 706th GrayJoKing 🇦🇺 814 221 19ms 31 Jul 2023 707th KatieLG 🇬🇧 813 75 367ms 7 Jan 2026 708th gnlow 🇰🇷 812 83 53ms 11 Feb 2025 708th LarsFredrikHolstTry 812 83 49ms 28 Oct 2025 710th Bubbler-4 812 85 314ms 17 Apr 2023 711th 2bular 812 95 3ms 3 Aug 2025 712th sisyphus-ppcg 🇦🇺 811 103 4ms 5 Oct 2023 712th dokutan 811 103 4ms 14 Sep 2024 714th edsrzf 🇳🇿 810 159 43ms 1 Sep 2025 715th dokutan 807 90 242ms 29 Jun 2024 716th nwellnhof 🇩🇪 807 119 4ms 28 Apr 2023 717th canissimia 🇦🇶 807 458 45ms 8 Jan 2024 718th snoozingnewt 🇨🇦 806 50 3ms 12 Dec 2025 719th plittlewood 806 73 383ms 16 Apr 2025 720th acotis 806 229 241ms 15 Dec 2025 First Prev 641–720 of 1,509 Next Last