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?
Diamonds 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 481st btnlq 722 79 1ms 16 Nov 2022 482nd rak1507 🇬🇧 722 108 129ms 23 Sep 2021 483rd edsrzf 🇳🇿 722 150 273ms 15 days ago 484th inventshah 721 80 1ms 8 Sep 2022 485th elisherer 🇮🇱 720 100 10ms 20 Apr 2019 485th Naruyoko 720 100 9ms 3 Mar 2023 485th emgordon154 720 100 10ms 6 Sep 2024 488th JRaspass 🇬🇧 718 51 151ms 3 Apr 2022 489th MeWhenI 🇻🇦 718 109 40ms 26 Aug 2023 489th albanian-laundromat 718 109 40ms 19 Aug 2025 491st Gaddy 🇫🇷 718 119 356ms 12 May 2022 492nd albanian-laundromat 717 124 2,679ms 15 days ago 493rd kaascevich 717 127 108ms 24 Jul 2025 494th Steffan153 🇫🇮 717 139 29ms 27 Dec 2022 495th primo-ppcg 🇹🇭 717 151 306ms 17 Apr 2020 496th snoozingnewt 🇨🇦 716 91 78ms 15 days ago 497th Reconcyl 715 109 128ms 5 Jan 2019 497th RussellEmerine 715 109 124ms 27 Feb 2020 499th MeWhenI 🇻🇦 714 138 483ms 7 Nov 2025 499th DardS8Br 714 138 357ms 5 Dec 2025 501st GrayJoKing 🇦🇺 713 45 2ms 12 Feb 2022 502nd RYNO8 713 77 11ms 26 Aug 2021 503rd GrayJoKing 🇦🇺 712 140 28ms 6 Jan 2023 504th clockworknazo 711 91 3ms 27 Feb 2023 505th KatieLG 🇬🇧 711 92 1,507ms 22 Oct 2021 506th stefangimmillaro 710 111 119ms 15 Oct 2022 507th CLOStrophobic 🇮🇹 710 124 7ms 23 Apr 2025 508th user189032 709 110 120ms 29 May 2019 509th emgordon154 709 130 158ms 14 Mar 2025 510th dee-gomma 706 102 10ms 31 Mar 2019 510th uttumuttu 🇫🇮 706 102 10ms 6 Jan 2022 512th bendapootie 706 121 362ms 21 Nov 2021 512th iznax 706 121 392ms 21 Nov 2021 514th typeswitch-dev 🇵🇹 705 122 3ms 22 Jul 2023 515th Andriamanitra 🇫🇮 704 81 383ms 23 Jul 2023 516th neihousaigaai 704 93 1,266ms 13 Feb 2024 517th MeWhenI 🇻🇦 704 112 3ms 12 Sep 2022 518th dokutan 703 92 2ms 26 Dec 2025 519th arjanadriaanse 🇳🇱 703 111 122ms 7 Feb 2022 520th Shanethegamer 🇺🇸 702 112 1,297ms 24 Jan 2024 521st qwertyuiop3 🇷🇺 702 130 61ms 29 May 2025 522nd prplz 🇦🇺 700 65 35ms 3 Jan 2020 523rd omurakazuaki 🇯🇵 699 103 9ms 18 Feb 2021 523rd neihousaigaai 699 103 9ms 17 Mar 2021 525th snoozingnewt 🇨🇦 699 155 281ms 15 days ago 525th CornerMercury 🇬🇧 699 155 259ms 14 days ago 527th 4hg 🇺🇸 696 94 1,231ms 8 Dec 2022 528th Yewzir 🇧🇪 696 221 2,215ms 14 Nov 2025 529th mokymok 🇺🇸 695 79 10ms 23 Jul 2021 529th jakobkordez 🇸🇮 695 79 10ms 31 Oct 2022 529th BlankSpruce 695 79 9ms 28 Aug 2024 529th Babafaba 695 79 9ms 12 Nov 2025 529th Lv0Sys 🇵🇱 695 79 10ms 1 Dec 2025 534th emgordon154 694 75 418ms 1 Aug 2024 535th yzzyx 694 156 278ms 21 Apr 2020 536th GrayJoKing 🇦🇺 692 76 4ms 11 Sep 2024 537th Shanethegamer 🇺🇸 692 104 10ms 28 Apr 2022 537th trinityy-7 692 104 9ms 22 Jul 2025 539th MeWhenI 🇻🇦 692 111 1ms 13 Aug 2024 540th KasperKivimaeki 🇫🇮 691 132 2,971ms 20 Nov 2025 541st stefangimmillaro 690 66 35ms 6 Jan 2023 541st anter69 🇭🇺 690 66 37ms 25 Jan 2023 541st tatzyr 🇯🇵 690 66 37ms 10 Dec 2024 544th Euler-37 690 106 39ms 4 Jun 2023 545th bendiscz 690 157 294ms 18 Apr 2020 546th emgordon154 689 223 1,696ms 22 Dec 2025 547th MeWhenI 🇻🇦 687 83 342ms 14 Feb 2023 548th albanian-laundromat 687 94 75ms 20 Nov 2025 549th Shanethegamer 🇺🇸 686 80 11ms 20 Aug 2021 550th drabart 🇵🇱 686 133 2,823ms 17 Nov 2023 551st Attero 🇸🇪 685 112 2ms 28 May 2020 551st keelimeguy 🇺🇸 685 112 2ms 4 Nov 2023 553rd plcc0 684 38 45ms 3 Mar 2025 554th o0lit3 🇺🇸 684 56 3ms 25 Sep 2020 554th kurkale6ka 684 56 3ms 3 Sep 2021 554th scpchicken 🇵🇼 684 56 3ms 4 Jan 2023 557th anastos 684 114 120ms 23 Jul 2018 557th DanielVenable 684 114 120ms 26 Mar 2025 559th dokutan 683 118 2ms 14 Jan 2026 560th tdkkdt 🇷🇺 683 125 434ms 21 Nov 2021 First Prev 481–560 of 2,544 Next Last