The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 7 days. Why not try and solve them ahead of time?
All holes in PHP 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 Holes Points Bytes Submitted 481st liemvo 🇻🇳 1 773 44 31 May 2021 481st Pyroan 1 773 44 17 Dec 2025 483rd dsech 1 770 87 26 Jan 2021 484th mwarvik 🇳🇴 1 767 73 16 Dec 2025 484th amazingalek 🇳🇴 1 767 73 16 Dec 2025 486th xyangst 1 758 62 3 Oct 2024 487th Playspal 1 757 74 16 Jul 2020 487th juef17 1 757 74 26 Feb 2021 487th two-bad 🇬🇧 1 757 74 14 Nov 2023 490th Bonjour27891 🇻🇳 1 750 48 9 Mar 2022 490th codereport 🇨🇦 1 750 48 16 Aug 2025 492nd qwertyuiop3 🇷🇺 1 750 56 8 Jun 2025 493rd Andrey2001 2 748 1,060 25 Jan 2026 494th Vasyan361 1 747 75 6 Apr 2019 494th JohnSpruijt 1 747 75 27 Sep 2024 494th julitroalves 1 747 75 31 Oct 2024 497th cafehaine 🇫🇷 2 747 1,084 31 Jan 2019 498th josev814 1 746 63 21 Jan 2026 499th klixel 🇨🇦 2 745 1,080 6 May 2023 500th colinodell 1 742 62 16 Apr 2020 500th dteague3989 1 742 62 17 Jul 2023 500th 1231234md5 🇨🇳 1 742 62 11 Dec 2023 503rd oriphi 1 742 66 17 Jun 2019 504th kkoenig 1 739 46 22 Dec 2023 505th marcus-gomes-v 🇧🇷 1 738 561 14 Dec 2021 506th ian-h-chamberlain 🇺🇸 1 731 67 29 Dec 2019 507th ytaki0801 🇯🇵 1 723 47 19 Jun 2021 507th VictorCanela 1 723 47 11 Sep 2024 509th user189032 1 721 68 30 May 2019 510th tegenton 1 720 50 4 Oct 2021 510th ozefe 🇹🇷 1 720 50 28 Oct 2021 510th beastedge 1 720 50 27 Apr 2022 510th RYSF13 🇨🇳 1 720 50 2 Nov 2025 514th dkarlovi 1 718 78 29 Sep 2017 514th alexandrebarbot 1 718 78 17 Aug 2018 514th dschoschu 1 718 78 20 Mar 2021 514th richard-oelze 🇩🇪 1 718 78 14 Oct 2023 514th Kemel91 1 718 78 4 Oct 2024 519th Isaac-NTT 1 709 79 4 Aug 2023 519th dmitryplus 1 709 79 10 Oct 2024 521st MichaelMBradley 🇨🇦 1 708 48 22 Mar 2022 521st oceko 1 708 48 26 Nov 2022 523rd Smetalo 1 708 65 25 Aug 2022 523rd mayrop 1 708 65 4 Nov 2022 525th MichalMarsalek 🇨🇿 2 701 1,062 13 Nov 2022 526th gubug0 1 700 70 13 Mar 2019 527th AndreasStokholm 1 700 80 7 Nov 2017 527th Xanatosinc 1 700 80 17 Apr 2020 527th tomas-bara 1 700 80 28 Apr 2020 527th bbakersmith 1 700 80 4 Jul 2021 527th Sparky83 1 700 80 19 Oct 2023 532nd johnennewdeeson 2 700 1,089 13 Oct 2017 533rd B3none 1 699 592 6 Oct 2022 534th GodlyProgrammer1 1 694 49 22 Nov 2025 535th rubikscubefan2010 1 693 597 2 Nov 2018 536th cbiggins 2 693 2,669 19 Sep 2024 537th brownkevg 1 692 78 2 Nov 2020 537th bartvw 1 692 78 26 Oct 2022 539th nic0pad 1 691 81 17 Aug 2018 539th galloj 🇨🇿 1 691 81 21 Sep 2022 541st p-vf 🇨🇭 1 687 67 25 Oct 2021 542nd j55d 1 685 54 16 Apr 2019 543rd timkelleher 1 683 82 17 Apr 2020 543rd lucien144 1 683 82 28 Apr 2020 543rd sawadee222 1 683 82 24 Feb 2023 543rd copoer 1 683 82 27 Feb 2023 543rd taylorsreid 1 683 82 22 Mar 2024 543rd jakk64 1 683 82 14 Nov 2024 549th Isaac-Metthez 1 682 107 20 Dec 2023 550th gauthier 1 680 50 17 Nov 2017 550th ArmaanAS 1 680 50 8 Mar 2021 550th kayahr 1 680 50 18 Jun 2021 550th wh3n3v3r 🇨🇿 1 680 50 15 Nov 2024 554th rifatx 2 676 1,082 23 Jul 2024 555th alxydu 2 674 471 3 Apr 2023 556th rossey 1 671 617 7 Nov 2024 557th RossBambrey 1 670 88 21 Nov 2023 558th TheRealOhead 🇺🇸 1 667 51 23 Nov 2022 558th CheeseCake628 🇳🇴 1 667 51 11 Mar 2023 560th ForkKILLET 🇨🇳 1 667 54 18 Feb 2021 First Prev 481–560 of 883 Next Last