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?
Roman to Arabic in all languages 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 Points Bytes Time Submitted 879th knutae 🇳🇴 594 160 21ms 17 Nov 2021 879th jfallon1997 594 160 23ms 5 Jan 2023 879th AtengChen 594 160 19ms 29 Aug 2024 884th yzhs 🇩🇪 592 75 41ms 7 Jun 2022 885th CaedenHarper 🇨🇦 592 98 6ms 18 Aug 2025 886th emgordon154 592 133 563ms 25 Sep 2024 887th CaedenHarper 🇨🇦 592 135 115ms 18 Aug 2025 888th timvermeulen 592 167 124ms 19 Jan 2020 889th ian-odonnell 590 129 16ms 9 Mar 2018 889th JohnSBarden 590 129 13ms 9 Nov 2021 891st CaedenHarper 🇨🇦 590 144 4ms 16 Nov 2025 892nd mtirado1 590 153 7ms 18 Apr 2023 893rd hardlyBearable 590 161 22ms 11 May 2019 893rd Psirving 590 161 20ms 1 Aug 2020 893rd SniperSmiley 🇺🇸 590 161 21ms 25 Jun 2022 893rd GulgDev 590 161 21ms 21 Mar 2023 897th KatieLG 🇬🇧 588 168 773ms 15 Jan 2023 898th ian-h-chamberlain 🇺🇸 588 194 156ms 6 Jan 2020 899th TheZwierzLF 🇵🇱 587 134 754ms 22 Nov 2025 900th msrawson 587 162 23ms 15 Aug 2018 901st Natanaelel 🇸🇪 586 145 4ms 16 Feb 2026 902nd omurakazuaki 🇯🇵 585 130 14ms 16 Feb 2021 903rd MeWhenI 🇻🇦 585 168 1,438ms 16 Jun 2023 904th SirBogman 🇺🇸 585 403 81ms 23 Nov 2022 905th fgrosshans 🇫🇷 583 163 21ms 10 Jun 2024 905th Papushkado 583 163 19ms 10 Nov 2025 907th emgordon154 583 336 1,614ms 6 Nov 2025 908th frankgraziano 582 173 22ms 24 Feb 2026 909th p01 581 131 22ms 7 Feb 2018 909th Florian-Mt 581 131 18ms 23 Oct 2023 911th madex 🇩🇪 581 160 190ms 14 days ago 912th PaulTaykalo 581 170 157ms 24 Sep 2020 913th CaedenHarper 🇨🇦 580 136 8ms 22 Aug 2025 914th wrhm 580 164 23ms 12 Dec 2020 914th zlee1 580 164 18ms 30 Apr 2021 914th hymanimy 580 164 20ms 8 Jan 2022 917th phdphil 579 107 179ms 22 Apr 2018 918th djeedjay 🇳🇱 578 147 3ms 6 Sep 2021 919th DanielRHolland 577 194 359ms 12 Nov 2020 920th Bodo171 576 165 19ms 5 Dec 2022 921st Yewzir 🇧🇪 575 139 143ms 9 Jun 2024 922nd markus-rekdal 573 166 20ms 28 May 2019 922nd ay2718 573 166 21ms 17 Jul 2019 922nd andre-lameirinhas 🇵🇹 573 166 21ms 4 Sep 2020 922nd kenny14231 573 166 19ms 5 Aug 2022 922nd KiwiLT 573 166 23ms 22 Nov 2022 922nd FlorianCassayre 🇫🇷 573 166 26ms 29 Jan 2023 922nd AdamMorris377 573 166 19ms 7 Sep 2024 929th DaCuteRaccoon 572 133 14ms 8 Dec 2022 930th Sciman101 571 158 6ms 16 May 2023 931st CaedenHarper 🇨🇦 571 173 773ms 22 Aug 2025 932nd janbehrens 🇩🇪 569 105 2,700ms 18 May 2023 933rd BrenSchaap 569 167 21ms 21 Oct 2021 933rd petroselo 569 167 19ms 29 Dec 2021 935th CaedenHarper 🇨🇦 569 181 71ms 16 Nov 2025 936th alexsave 568 134 21ms 14 Jan 2026 937th annaproxy 568 197 327ms 23 Feb 2023 938th Jacob385 567 181 388ms 28 Oct 2025 939th cingulataluke 566 168 21ms 30 Aug 2023 939th RaBa21 🇭🇺 566 168 19ms 12 Jul 2025 941st melven 566 215 42ms 16 Oct 2025 942nd XenThe 🇬🇧 563 135 18ms 12 Jun 2025 943rd TheAristos 562 169 21ms 1 Nov 2019 943rd mishak-sys 562 169 21ms 9 Sep 2025 945th BambooleanLogic 🇸🇪 559 136 18ms 3 Nov 2022 946th itiievskyi 🇺🇦 559 170 21ms 10 Aug 2020 946th glesnick 559 170 20ms 6 Oct 2022 946th SB-945 559 170 28ms 7 Apr 2024 946th ziselsberger 559 170 28ms 7 Oct 2024 946th croc54 559 170 19ms 13 Jan 2025 951st emgordon154 558 104 7ms 26 Jul 2024 952nd emgordon154 557 221 110ms 10 Jun 2025 953rd AkashTandon167 556 171 24ms 21 Nov 2020 953rd cros107 🇦🇺 556 171 29ms 14 Feb 2024 955th kkoenig 555 228 317ms 13 Sep 2024 956th amollberg 🇸🇪 553 172 28ms 16 Feb 2022 956th mbittner20 553 172 21ms 27 May 2023 956th CutSandstone 553 172 30ms 7 Jul 2024 959th uttumuttu 🇫🇮 551 138 20ms 5 Jan 2022 959th KaleChips22 551 138 13ms 3 Aug 2025 First Prev 881–960 of 1,514 Next Last