The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 3 days. Why not try and solve them ahead of time?
Arabic to Roman 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 721st Seek64 🇩🇪 615 140 27ms 3 Feb 2025 722nd bac0id 615 219 445ms 3 Jul 2024 723rd Shanethegamer 🇺🇸 615 237 332ms 28 Jan 2024 724th DialFrost 🇸🇬 614 99 44ms 15 Apr 2025 725th Shanethegamer 🇺🇸 614 185 563ms 28 Jan 2024 726th uttumuttu 🇫🇮 613 142 26ms 4 Jan 2022 726th iliazeus 613 142 19ms 3 Sep 2022 726th LukeBridges 🇬🇧 613 142 23ms 28 Oct 2022 726th madeforlosers 613 142 20ms 2 Nov 2023 730th labster 613 161 3,943ms 15 Mar 2018 731st arjanadriaanse 🇳🇱 612 238 348ms 7 Feb 2022 732nd janbehrens 🇩🇪 611 186 498ms 24 Mar 2022 733rd marcin7Cd 610 141 22ms 27 Jun 2020 733rd ryyyn 🇺🇸 610 141 22ms 9 Oct 2025 735th dokutan 609 109 84ms 22 Jan 2024 736th mamamia5x 608 143 14ms 8 Mar 2024 737th duckyluuk 🇳🇱 608 187 3,241ms 26 Oct 2024 738th davidwangd 607 240 327ms 6 Apr 2025 739th bizy-coder 606 142 41ms 26 Nov 2025 740th MeWhenI 🇻🇦 605 163 66ms 3 Jul 2023 741st FireyFly 604 144 20ms 14 Apr 2018 741st skps2010 604 144 14ms 1 Jan 2019 741st didion0 🇺🇸 604 144 15ms 22 Apr 2021 741st NewDefectus 🇮🇱 604 144 16ms 8 Oct 2021 741st raphaelimahorn 604 144 17ms 26 Oct 2022 746th ccbrown 604 255 393ms 21 Apr 2020 747th Shanethegamer 🇺🇸 602 101 67ms 4 Apr 2023 748th bricknellj 602 143 19ms 3 Nov 2022 748th vishwathg 602 143 369ms 8 Sep 2023 748th ahmetdemirag 🇨🇾 602 143 24ms 9 Mar 2025 748th bzijlema 🇳🇱 602 143 49ms 14 Jan 2026 752nd lynn 602 185 30ms 23 Nov 2021 753rd dokutan 601 170 11ms 2 Feb 2026 754th jkelly467 599 190 3,695ms 12 Jan 2026 755th Irratix 🇳🇱 599 225 465ms 9 Jan 2022 756th TFeld00 🇩🇰 598 144 52ms 21 Apr 2022 756th jared-hughes 598 144 19ms 14 Mar 2023 758th cmdrsabre 597 253 194ms 6 Feb 2020 759th legrottagliegionata 596 146 22ms 7 Dec 2021 760th stefangimmillaro 595 166 77ms 19 Oct 2022 761st YAJUE114514 595 245 325ms 22 days ago 762nd tpaxman 🇨🇦 594 145 28ms 17 Dec 2020 762nd rowechenzhong 594 145 29ms 26 Nov 2021 762nd Lv0Sys 🇵🇱 594 145 21ms 19 Feb 2026 765th MeWhenI 🇻🇦 594 227 440ms 14 Nov 2022 766th nsprd 594 277 195ms 16 Jan 2024 767th trinityy-7 592 147 19ms 26 Jan 2026 768th janbehrens 🇩🇪 591 228 1,412ms 20 Nov 2022 769th blaztoma 🇱🇹 591 233 163ms 28 Nov 2025 770th dyc3 590 146 38ms 27 Jul 2020 770th Augigogigi 590 146 26ms 28 Jul 2020 770th BrunoVisnadi 🇧🇷 590 146 19ms 26 Sep 2025 773rd ovs-code 🇩🇪 590 155 33ms 3 Feb 2023 774th daniel-pedersen 🇸🇪 588 148 18ms 6 Mar 2022 774th stop-amertime 588 148 16ms 5 Dec 2022 776th aDwarfNamedUrist 588 248 378ms 4 Oct 2023 777th Shanethegamer 🇺🇸 587 154 1,505ms 28 Jan 2024 778th ZakkkkAttackkkk 🇵🇭 587 174 7ms 12 Nov 2023 779th lynn 587 181 234ms 18 May 2021 780th dokutan 587 194 3,713ms 2 Nov 2024 781st anoopsg 🇮🇳 587 207 147ms 18 Nov 2023 782nd dcgjb 586 127 3,542ms 16 May 2024 783rd davecame 586 147 21ms 27 Mar 2024 784th annaproxy 586 203 426ms 13 Mar 2022 785th Yewzir 🇧🇪 585 143 1,749ms 16 Nov 2025 786th FlyingPenguin223 585 198 6ms 30 Nov 2024 787th KatieLG 🇬🇧 585 258 830ms 15 Jan 2023 788th daisy-lau 584 149 15ms 13 Jul 2020 788th satowine1 584 149 14ms 7 Dec 2021 788th Ashikpaul 🇮🇳 584 149 15ms 29 Jul 2022 788th Maznek 584 149 20ms 21 Jun 2023 788th Yewzir 🇧🇪 584 149 19ms 16 Feb 2024 793rd sultan 584 204 457ms 30 Apr 2024 794th Lv0Sys 🇵🇱 583 195 498ms 27 Nov 2025 795th Frowny 582 67 9ms 10 Jan 2022 796th luftj 582 148 30ms 23 Apr 2020 796th Stockoh 🇫🇷 582 148 39ms 5 May 2023 796th janbehrens 🇩🇪 582 148 20ms 17 Jun 2023 796th edsrzf 🇳🇿 582 148 21ms 22 Jul 2025 800th boxjelly 582 249 648ms 25 Feb 2021 First Prev 721–800 of 1,907 Next Last