The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 5 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 881st KevinMarquette 🇺🇸 551 135 1,375ms 17 Apr 2022 882nd neihousaigaai 551 158 18ms 28 Apr 2021 882nd alexsave 551 158 24ms 14 Jan 2026 884th Narik1 551 216 403ms 3 Apr 2023 884th postie77 551 216 461ms 19 May 2023 884th JDiLenarda 🇫🇷 551 216 438ms 21 Nov 2023 887th Narik1 550 280 323ms 3 Apr 2023 888th dokutan 549 261 18ms 3 Oct 2024 889th Zpuy 549 300 194ms 2 hours ago 890th yanjs 548 157 20ms 30 Sep 2021 891st MeWhenI 🇻🇦 547 141 386ms 15 Feb 2023 892nd somebody1234 547 159 19ms 24 Mar 2018 892nd coreynash 547 159 20ms 26 Sep 2023 892nd zekestephens 547 159 19ms 25 Oct 2025 895th BlankSpruce 546 187 10ms 26 Aug 2022 895th violeta-desantis 546 187 11ms 13 Apr 2024 897th tomh1012 546 218 430ms 8 Sep 2025 898th inventshah 545 158 22ms 24 Jan 2023 898th mediocr3 545 158 22ms 19 Jul 2023 898th Mabeloid 🇳🇴 545 158 21ms 17 Sep 2024 898th andrewjc2000 545 158 22ms 10 Jul 2025 902nd joshuaxie8 545 266 489ms 9 Jul 2025 903rd RockOfStone 544 213 5ms 22 Dec 2022 904th dokutan 544 214 18ms 3 Oct 2024 905th tegenton 543 188 10ms 5 Oct 2021 905th Irratix 🇳🇱 543 188 11ms 8 Mar 2022 905th RealAMC 🇳🇿 543 188 11ms 21 Nov 2023 905th Maashau 543 188 11ms 24 Nov 2025 909th PiterAnnema 541 159 28ms 30 Aug 2020 909th StefanHabel 🇨🇦 541 159 25ms 11 Nov 2022 909th stacksparrow4 541 159 25ms 29 Aug 2023 912th JOrE20 540 161 25ms 4 Jan 2026 913th DialFrost 🇸🇬 540 189 10ms 11 Dec 2023 913th nsprd 540 189 10ms 19 Jan 2024 915th HumanoidCPU 540 197 218ms 11 Jun 2024 915th dokutan 540 197 216ms 15 Aug 2025 917th emgordon154 540 285 306ms 17 Jan 2025 918th ian-h-chamberlain 🇺🇸 540 305 178ms 4 Feb 2020 919th inventshah 539 145 422ms 22 Jan 2024 920th MeWhenI 🇻🇦 539 155 1,994ms 29 Aug 2025 921st Lv0Sys 🇵🇱 538 286 298ms 27 Nov 2025 922nd MeWhenI 🇻🇦 537 140 153ms 3 Aug 2024 923rd ian-odonnell 537 162 15ms 12 Mar 2018 923rd alexkunin 537 162 16ms 7 Jul 2019 923rd gigaprofisi 🇺🇸 537 162 17ms 7 Aug 2025 926th AGoyet 535 161 22ms 26 Jul 2022 926th NDR0216 🇹🇼 535 161 20ms 4 Jul 2024 926th zhaohm14 535 161 20ms 6 Jun 2025 929th Florian-Mt 534 163 14ms 14 Nov 2023 929th Protothor 534 163 20ms 16 days ago 931st Shanethegamer 🇺🇸 533 185 13ms 28 Jan 2024 932nd mbuchel 533 233 399ms 28 Aug 2021 933rd LouisRustenholz 531 162 46ms 23 Dec 2021 933rd tobyLovick 531 162 22ms 7 Dec 2023 935th TheEric0802 🇩🇪 531 172 18ms 22 Sep 2023 936th KarstenHohmeier 531 186 14ms 8 Mar 2018 937th mpldr 🇩🇪 529 291 309ms 24 Mar 2025 938th commandz0 🇺🇸 528 148 597ms 1 Sep 2025 939th M4rc0g1 528 163 20ms 22 Nov 2025 940th janAkali 🇷🇺 528 235 368ms 16 days ago 941st KatieLG 🇬🇧 528 326 200ms 19 May 2024 942nd Bubbler-4 527 74 4ms 19 Jan 2022 943rd jcheritat 527 165 22ms 6 Sep 2020 944th iczelia 🇩🇪 527 180 69ms 10 Oct 2025 945th roavin 526 194 11ms 13 May 2022 946th HumanoidCPU 526 272 11ms 19 Aug 2024 947th mbittner20 525 164 21ms 27 May 2023 947th iliaspapa 525 164 25ms 10 Dec 2025 949th blaztoma 🇱🇹 524 116 63ms 13 Oct 2025 950th NatNgs 524 166 27ms 9 Jan 2020 950th tomh1012 524 166 16ms 25 Aug 2020 950th aksyristos 524 166 24ms 29 Oct 2022 953rd albanian-laundromat 524 181 12ms 13 Jul 2025 954th bac0id 524 195 10ms 3 Jul 2024 955th viv511 524 257 542ms 3 Feb 2025 956th ashscodes 524 294 382ms 19 Nov 2023 957th MeWhenI 🇻🇦 523 204 12ms 6 Aug 2023 958th YoungjuneKwon 522 165 26ms 19 Dec 2018 958th neihousaigaai 522 165 23ms 6 Oct 2024 958th Deedogg 522 165 34ms 30 Oct 2025 First Prev 881–960 of 1,906 Next Last