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?
Catalan 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 638th commandz0 🇺🇸 857 43 395ms 1 Sep 2025 638th dokutan 857 43 412ms 26 Feb 2026 643rd jrm5399 🇰🇿 857 50 10ms 30 Jan 2022 643rd Freddiechang 857 50 9ms 8 Mar 2024 645th inventshah 857 79 2,798ms 25 Oct 2024 645th error256 857 79 2,726ms 26 Oct 2024 645th emgordon154 857 79 2,639ms 1 Nov 2024 648th 386asm 🇺🇸 857 175 43ms 4 May 2023 649th MeWhenI 🇻🇦 856 59 48ms 13 Feb 2025 649th DialFrost 🇸🇬 856 59 42ms 13 Feb 2025 649th Shanethegamer 🇺🇸 856 59 39ms 13 Feb 2025 649th pardouin 🇫🇷 856 59 43ms 20 Mar 2025 653rd Codsilla 🇨🇦 855 43 489ms 3 Nov 2023 653rd Daniel-Ellison 855 43 360ms 10 Aug 2025 653rd Lv0Sys 🇵🇱 855 43 278ms 6 Dec 2025 656th primo-ppcg 🇹🇭 855 129 40ms 14 Jan 2025 657th Natanaelel 🇸🇪 854 58 1,326ms 3 Jan 2024 658th GolfingSuccess 🇬🇷 854 62 6ms 9 Feb 2026 659th arcpolaris 854 85 415ms 16 Dec 2024 660th primo-ppcg 🇹🇭 854 218 5ms 6 Aug 2023 661st albanian-laundromat 854 300 26ms 17 days ago 662nd KatieLG 🇬🇧 853 36 37ms 10 Apr 2022 662nd SirBogman 🇺🇸 853 36 37ms 17 May 2022 662nd Babafaba 853 36 36ms 15 Oct 2025 662nd JOrE20 853 36 35ms 11 Feb 2026 666th MeWhenI 🇻🇦 853 73 488ms 28 Feb 2022 666th Shanethegamer 🇺🇸 853 73 487ms 23 Mar 2022 666th DialFrost 🇸🇬 853 73 504ms 26 Oct 2023 666th jipsong 🇩🇪 853 73 476ms 1 Jul 2024 666th emgordon154 853 73 513ms 25 May 2025 671st JayXon 🇺🇸 853 141 154ms 4 Apr 2025 672nd ovs-code 🇩🇪 853 180 10ms 15 Jul 2023 673rd GrayJoKing 🇦🇺 852 21 44ms 28 Jul 2022 673rd ovs-code 🇩🇪 852 21 41ms 2 Feb 2024 673rd xsot 🇸🇬 852 21 40ms 9 Jun 2024 673rd pardouin 🇫🇷 852 21 40ms 11 Oct 2024 673rd CornerMercury 🇬🇧 852 21 39ms 4 days ago 678th FlyingPenguin223 850 20 2ms 17 Oct 2024 679th j-Ewan 850 138 278ms 10 Mar 2022 680th Shanethegamer 🇺🇸 849 72 119ms 22 May 2025 680th blaztoma 🇱🇹 849 72 112ms 28 Nov 2025 682nd sean-niemann 🇺🇸 849 194 11ms 17 Dec 2025 683rd canissimia 🇦🇶 848 135 3ms 30 Jan 2022 683rd btnlq 848 135 4ms 17 Nov 2022 685th dokutan 847 68 7ms 26 Feb 2026 686th duckyluuk 🇳🇱 847 215 20ms 29 Nov 2025 687th sisyphus-ppcg 🇦🇺 846 42 29ms 22 May 2022 687th primo-ppcg 🇹🇭 846 42 33ms 23 May 2022 687th iakolzin 846 42 29ms 28 May 2022 687th saito-ta 🇯🇵 846 42 30ms 8 Jun 2022 687th nwellnhof 🇩🇪 846 42 32ms 8 Jun 2022 687th fuzzylojik-golf 🇺🇸 846 42 30ms 20 Sep 2025 693rd Shanethegamer 🇺🇸 846 48 75ms 11 Mar 2023 694th SirBogman 🇺🇸 845 36 248ms 17 May 2022 695th DialFrost 🇸🇬 845 53 10ms 24 Mar 2025 696th annaproxy 844 86 385ms 5 May 2022 697th JRaspass 🇬🇧 844 139 311ms 7 Feb 2024 697th Shanethegamer 🇺🇸 844 139 302ms 7 Feb 2024 697th DialFrost 🇸🇬 844 139 290ms 7 Feb 2024 700th fuzzylojik-golf 🇺🇸 843 75 103ms 8 Sep 2025 700th sean-niemann 🇺🇸 843 75 116ms 21 Sep 2025 702nd JOrE20 843 304 26ms 11 Feb 2026 703rd Bubbler-4 842 46 64ms 13 Sep 2023 704th nwellnhof 🇩🇪 842 136 3ms 3 Dec 2022 705th snoozingnewt 🇨🇦 841 74 504ms 3 Dec 2025 706th ToE42 840 51 10ms 31 Jan 2022 706th kyleclaassen 840 51 9ms 12 Mar 2022 706th PiterAnnema 840 51 10ms 23 Mar 2022 706th OllieBoyne 🇬🇧 840 51 10ms 15 Apr 2022 706th TobyBoyne 🇬🇧 840 51 10ms 15 Apr 2022 706th SniperSmiley 🇺🇸 840 51 12ms 2 Jun 2022 706th abailey2020 🇺🇸 840 51 10ms 23 Jul 2022 706th suwat513 840 51 9ms 22 Sep 2022 706th 4ndyJ 🇬🇧 840 51 9ms 19 Jan 2023 706th CheeseCake628 🇳🇴 840 51 10ms 20 Feb 2023 706th DanielPeterssonAI 840 51 10ms 15 Mar 2023 706th Erik-M-Larsson 840 51 10ms 4 Apr 2023 706th mbittner20 840 51 9ms 12 Jun 2023 706th elgan65536 🇺🇸 840 51 10ms 6 Mar 2024 706th Alex-x90 🇺🇸 840 51 9ms 5 May 2024 First Prev 641–720 of 2,051 Next Last