The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 4 days. Why not try and solve them ahead of time?
Kaprekar Numbers 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 797th MeWhenI 🇻🇦 165 441 3ms 2 Nov 2024 797th CaedenHarper 🇨🇦 165 441 3ms 31 Jan 2025 797th KatieLG-Transpiler 🇬🇧 165 441 3ms 9 Jan 2026 804th dokutan 165 445 2,473ms 1 Nov 2024 804th MeWhenI 🇻🇦 165 445 2,374ms 2 Nov 2024 804th CaedenHarper 🇨🇦 165 445 2,340ms 1 Feb 2025 807th HumanoidCPU 165 458 404ms 1 Nov 2024 807th Shanethegamer 🇺🇸 165 458 402ms 1 Nov 2024 807th dokutan 165 458 401ms 1 Nov 2024 807th mwarvik 🇳🇴 165 458 417ms 5 Jan 2026 811th HumanoidCPU 162 452 2,438ms 1 Nov 2024 811th Shanethegamer 🇺🇸 162 452 2,490ms 1 Nov 2024 813th HumanoidCPU 160 657 30ms 4 Nov 2025 814th dokutan 159 318 53ms 1 Nov 2024 815th CaedenHarper 🇨🇦 159 659 26ms 16 Aug 2025 816th KatieLG-Transpiler 🇬🇧 159 660 26ms 9 Jan 2026 817th KatieLG-Transpiler 🇬🇧 156 522 374ms 9 Jan 2026 818th dokutan 155 349 125ms 27 Dec 2025 819th dokutan 155 509 37ms 1 Nov 2024 819th MeWhenI 🇻🇦 155 509 37ms 2 Nov 2024 819th CaedenHarper 🇨🇦 155 509 37ms 22 Jan 2025 819th JOrE20 155 509 38ms 2 Feb 2026 823rd KatieLG 🇬🇧 155 510 36ms 1 Nov 2024 824th KatieLG-Transpiler 🇬🇧 155 531 113ms 9 Jan 2026 825th Kokusui 🇯🇵 154 434 5ms 19 Nov 2024 826th HumanoidCPU 154 454 79ms 1 Nov 2024 826th dokutan 154 454 71ms 1 Nov 2024 826th CaedenHarper 🇨🇦 154 454 74ms 16 Aug 2025 829th snoozingnewt 🇨🇦 154 476 2,532ms 27 Sep 2025 830th KatieLG-Transpiler 🇬🇧 154 511 36ms 9 Jan 2026 831st denkyuu1 153 346 34ms 21 days ago 832nd JunkIce 153 449 9ms 21 Nov 2024 833rd HumanoidCPU 152 448 148ms 1 Nov 2024 833rd dokutan 152 448 144ms 1 Nov 2024 833rd Shanethegamer 🇺🇸 152 448 139ms 1 Nov 2024 833rd MeWhenI 🇻🇦 152 448 143ms 2 Nov 2024 833rd CaedenHarper 🇨🇦 152 448 134ms 16 Aug 2025 838th HumanoidCPU 152 452 10ms 1 Nov 2024 838th GolfingSuccess 🇬🇷 152 452 10ms 1 Nov 2024 838th zbreit 🇺🇸 152 452 10ms 1 Nov 2024 838th Shanethegamer 🇺🇸 152 452 10ms 1 Nov 2024 838th madex 🇩🇪 152 452 10ms 1 Nov 2024 838th jtaxen 152 452 10ms 1 Nov 2024 838th Stockoh 🇫🇷 152 452 9ms 4 Nov 2024 838th evan18c 152 452 10ms 7 Nov 2024 838th roguh 🇬🇹 152 452 9ms 27 Nov 2024 838th mathisfun271 152 452 10ms 25 Jan 2025 838th moustave 152 452 10ms 9 Apr 2025 838th SectorCorruptor 152 452 10ms 24 Jul 2025 838th vgamula 🇺🇦 152 452 11ms 25 Jul 2025 838th Unknownuserfrommars 152 452 10ms 5 Aug 2025 838th JOrE20 152 452 10ms 6 Nov 2025 838th TheSecondComing123 152 452 10ms 25 Feb 2026 854th Shanethegamer 🇺🇸 151 443 4ms 8 May 2025 855th Shanethegamer 🇺🇸 151 450 798ms 16 Apr 2025 855th KatieLG 🇬🇧 151 450 841ms 20 Apr 2025 855th dokutan 151 450 877ms 23 Jul 2025 855th HumanoidCPU 151 450 820ms 18 Aug 2025 855th MeWhenI 🇻🇦 151 450 839ms 15 Sep 2025 860th HumanoidCPU 150 445 4ms 1 Nov 2024 860th dokutan 150 445 4ms 1 Nov 2024 860th MeWhenI 🇻🇦 150 445 4ms 2 Nov 2024 860th fischfood 150 445 5ms 8 Nov 2024 860th CaedenHarper 🇨🇦 150 445 5ms 16 Aug 2025 865th HumanoidCPU 150 448 1ms 1 Nov 2024 865th Shanethegamer 🇺🇸 150 448 1ms 1 Nov 2024 865th koipondx86 150 448 1ms 1 Nov 2024 865th MeWhenI 🇻🇦 150 448 1ms 2 Nov 2024 865th CaedenHarper 🇨🇦 150 448 1ms 16 Aug 2025 870th KasperKivimaeki 🇫🇮 150 457 10ms 15 Jul 2025 871st muser-logiccpu 🇺🇦 150 458 9ms 9 Aug 2025 871st netfri25 🇮🇱 150 458 10ms 21 Feb 2026 871st rotemkm 150 458 10ms 21 Feb 2026 874th KatieLG-Transpiler 🇬🇧 149 538 419ms 9 Jan 2026 875th Unknownuserfrommars 149 557 3,329ms 10 Dec 2024 876th HumanoidCPU 148 456 1ms 1 Nov 2024 876th dokutan 148 456 1ms 1 Nov 2024 876th Shanethegamer 🇺🇸 148 456 2ms 1 Nov 2024 876th CaedenHarper 🇨🇦 148 456 1ms 23 Jan 2025 876th Maashau 148 456 2ms 12 Dec 2025 First Prev 801–880 of 1,113 Next Last