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 875th andrewjc2000 560 98 9ms 2 Jul 2025 875th Nhan-TRANvan_keyloop 560 98 10ms 20 Aug 2025 875th countlpaul-dotcom 560 98 10ms 19 Oct 2025 884th neihousaigaai 560 176 404ms 30 Apr 2021 885th SpareManiKatti 558 129 10ms 13 Oct 2021 885th Nico-Kasz 558 129 9ms 19 Apr 2022 885th adamnielson42 🇺🇸 558 129 12ms 25 Apr 2023 888th Kloppermand 🇩🇰 558 153 368ms 6 Jan 2023 889th marcin7Cd 558 225 2ms 31 Aug 2019 890th benson-z 557 177 405ms 1 Sep 2023 891st c0d3-4-F00d 🇩🇪 556 138 1ms 8 Feb 2022 892nd Waffle3z 555 82 34ms 17 Oct 2020 892nd AgentIvan 🇺🇦 555 82 37ms 28 Jan 2021 894th drew-loukusa 555 99 10ms 26 May 2020 894th Secozzi 555 99 11ms 20 Oct 2020 894th seanshpark 555 99 10ms 18 Dec 2020 894th soalyer 555 99 9ms 9 Nov 2021 894th CodyMiner 555 99 10ms 14 Nov 2021 894th MichalMarsalek 🇨🇿 555 99 9ms 23 Oct 2022 894th logvp 555 99 10ms 6 Oct 2024 894th BREMAUCY 🇫🇷 555 99 10ms 7 Aug 2025 894th cros107 🇦🇺 555 99 10ms 2 Jan 2026 894th Pyroan 555 99 10ms 5 Jan 2026 904th juliansiebert 🇩🇪 554 86 226ms 23 Jul 2022 904th krcs 🇵🇱 554 86 250ms 15 Oct 2024 906th FEZfan 🇦🇺 554 94 561ms 26 Apr 2025 907th shuding 554 130 10ms 6 May 2020 907th dokutan 554 130 10ms 20 Apr 2025 909th MeWhenI 🇻🇦 553 58 3ms 4 Feb 2022 910th Shanethegamer 🇺🇸 553 95 4ms 16 Aug 2024 911th PiterAnnema 549 100 10ms 23 Mar 2022 911th neihousaigaai 549 100 10ms 17 Apr 2022 911th Heathcorp 🇦🇺 549 100 12ms 2 Dec 2022 911th aksyristos 549 100 9ms 2 Feb 2023 911th madex 🇩🇪 549 100 10ms 9 Jul 2024 911th evan18c 549 100 10ms 22 Apr 2025 911th LvLError 549 100 10ms 29 May 2025 911th vgamula 🇺🇦 549 100 10ms 5 Aug 2025 919th Yewzir 🇧🇪 547 144 117ms 28 Mar 2024 920th joelgduggan 547 156 405ms 21 Nov 2021 921st mcreenan 546 67 145ms 20 Jun 2018 922nd Irratix 🇳🇱 546 167 418ms 3 Jan 2022 923rd Natanaelel 🇸🇪 545 132 9ms 11 May 2022 923rd CallanMcNulty 545 132 11ms 30 Sep 2022 923rd aksyristos 545 132 11ms 28 Dec 2022 926th Andriamanitra 🇫🇮 545 156 4ms 13 Jun 2024 927th klixel 🇨🇦 545 169 146ms 9 Jun 2023 928th NewDefectus 🇮🇱 544 101 10ms 21 Apr 2021 928th eddvrs 544 101 9ms 20 Aug 2022 928th commandz0 🇺🇸 544 101 10ms 29 Sep 2022 928th benson-z 544 101 10ms 6 Dec 2024 932nd Herbert00709 🇵🇱 544 141 2ms 8 Jun 2024 933rd aliakseikalosha 544 157 393ms 22 Oct 2024 934th akusumoto 🇯🇵 542 170 153ms 6 Apr 2022 935th vibdev 541 133 10ms 26 Aug 2021 936th Jandoife 541 142 2ms 9 Dec 2022 937th Ashray-g 🇺🇸 541 182 393ms 1 Sep 2023 938th Shanethegamer 🇺🇸 540 158 376ms 9 Apr 2025 939th scpchicken 🇵🇼 538 102 10ms 26 Mar 2022 939th mdnestor 538 102 11ms 27 Dec 2022 939th FranklinJiaChen 538 102 9ms 19 Jul 2024 939th BoBz200 538 102 10ms 9 Nov 2024 939th FortuiteMan 🇫🇷 538 102 10ms 3 Dec 2025 944th eranws 537 134 11ms 16 Oct 2022 944th bremersj 537 134 10ms 24 Oct 2025 946th n8pjl 537 143 2ms 29 Oct 2023 947th arctouch-cristiannevianna 537 159 392ms 4 Mar 2024 948th MeWhenI 🇻🇦 537 170 440ms 14 Nov 2022 949th KevinMarquette 🇺🇸 536 89 257ms 5 Jun 2020 949th TimCurwick 🇺🇸 536 89 265ms 27 Jan 2021 949th JPRuskin 🇬🇧 536 89 264ms 1 May 2024 952nd MichalMarsalek 🇨🇿 536 97 458ms 21 Jan 2024 953rd mousetail 🇳🇱 536 118 5ms 22 Oct 2024 954th dokutan 536 168 480ms 27 Dec 2025 955th JOrE20 535 203 60ms 9 Feb 2026 956th Yewzir 🇧🇪 535 217 16ms 34 hours ago 957th bizy-coder 535 235 2ms 20 Jan 2024 958th ericlangedijk 🇸🇮 534 160 388ms 22 May 2023 959th aalanso 534 171 2,884ms 18 Nov 2023 960th P-Quentin 🇫🇷 533 103 10ms 11 Aug 2022 First Prev 881–960 of 2,543 Next Last