The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 22 hours. Why not try and solve them ahead of time?
Tutorial 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 800th CLOStrophobic 🇮🇹 0 62 3ms 4 Feb 2025 800th DialFrost 🇸🇬 0 62 11ms 15 Feb 2025 800th dokutan 0 62 2,017ms 15 Jul 2025 800th 6512345 0 62 161ms 4 Nov 2025 805th kg583 🇺🇸 0 63 49ms 21 Nov 2024 805th emgordon154 0 63 166ms 28 Nov 2024 805th rucin93 🇵🇱 0 63 182ms 3 Dec 2024 805th lukegustafson 🇺🇸 0 63 181ms 7 Dec 2024 805th sean-niemann 🇺🇸 0 63 162ms 10 Dec 2024 805th MeWhenI 🇻🇦 0 63 6ms 18 Dec 2024 805th zacjl 0 63 52ms 31 Dec 2024 805th Shanethegamer 🇺🇸 0 63 182ms 10 Jan 2025 805th CLOStrophobic 🇮🇹 0 63 58ms 17 Jan 2025 805th edsrzf 🇳🇿 0 63 50ms 9 Feb 2025 805th GolfingSuccess 🇬🇷 0 63 49ms 9 Feb 2025 805th Nemikolh 🇫🇷 0 63 13ms 12 Feb 2025 805th GolfingSuccess 🇬🇷 0 63 189ms 20 Feb 2025 805th varhammer 0 63 6ms 22 Feb 2025 805th voytxt 🇨🇿 0 63 189ms 17 Apr 2025 805th FlyingPenguin223 0 63 51ms 17 Apr 2025 805th DialFrost 🇸🇬 0 63 185ms 17 Apr 2025 805th DialFrost 🇸🇬 0 63 5ms 17 Apr 2025 805th DialFrost 🇸🇬 0 63 49ms 17 Apr 2025 805th pardouin 🇫🇷 0 63 176ms 17 Apr 2025 805th Shanethegamer 🇺🇸 0 63 5ms 17 Apr 2025 805th Shanethegamer 🇺🇸 0 63 54ms 17 Apr 2025 805th GolfingSuccess 🇬🇷 0 63 6ms 17 Apr 2025 805th HumanoidCPU 0 63 177ms 18 Apr 2025 805th HumanoidCPU 0 63 7ms 18 Apr 2025 805th HumanoidCPU 0 63 50ms 18 Apr 2025 805th CaedenHarper 🇨🇦 0 63 163ms 18 Apr 2025 805th CaedenHarper 🇨🇦 0 63 6ms 18 Apr 2025 805th CaedenHarper 🇨🇦 0 63 56ms 18 Apr 2025 805th dokutan 0 63 158ms 28 Apr 2025 805th dokutan 0 63 6ms 28 Apr 2025 805th Jigglypuffed 0 63 50ms 19 Jul 2025 805th penous 0 63 14ms 2 Aug 2025 805th YellowDudeIsMe 0 63 14ms 14 Aug 2025 805th albanian-laundromat 0 63 6ms 22 Aug 2025 805th snoozingnewt 🇨🇦 0 63 183ms 15 Sep 2025 805th snoozingnewt 🇨🇦 0 63 6ms 15 Sep 2025 805th snoozingnewt 🇨🇦 0 63 52ms 15 Sep 2025 805th luuumine 🇫🇷 0 63 2ms 10 Nov 2025 805th JOrE20 0 63 6ms 18 Nov 2025 805th kayaulai 0 63 93ms 23 Nov 2025 846th Shanethegamer 🇺🇸 0 64 142ms 20 Nov 2024 846th error256 0 64 131ms 21 Nov 2024 846th error256 0 64 1,021ms 21 Nov 2024 846th emgordon154 0 64 2ms 26 Nov 2024 846th Liniarc 0 64 13ms 26 Nov 2024 846th MeWhenI 🇻🇦 0 64 49ms 12 Dec 2024 846th luuumine 🇫🇷 0 64 1,021ms 16 Oct 2025 846th GolfingSuccess 🇬🇷 0 64 3ms 12 Nov 2025 846th GolfingSuccess 🇬🇷 0 64 155ms 2 Dec 2025 846th Shanethegamer 🇺🇸 0 64 152ms 4 Dec 2025 846th GolfingSuccess 🇬🇷 0 64 110ms 15 Dec 2025 846th amazingalek 🇳🇴 0 64 11ms 16 Dec 2025 846th error256 0 64 150ms 3 Feb 2026 846th pardouin 🇫🇷 0 64 167ms 4 Feb 2026 860th Shanethegamer 🇺🇸 0 65 8ms 20 Nov 2024 860th stefangimmillaro 0 65 10ms 20 Nov 2024 860th kg583 🇺🇸 0 65 10ms 21 Nov 2024 860th khvdm 0 65 12ms 21 Nov 2024 860th edsrzf 🇳🇿 0 65 10ms 21 Nov 2024 860th hallvabo 🇳🇴 0 65 11ms 24 Nov 2024 860th ovs-code 🇩🇪 0 65 12ms 25 Nov 2024 860th GolfingSuccess 🇬🇷 0 65 12ms 25 Nov 2024 860th AlephSquirrel 0 65 10ms 25 Nov 2024 860th AlephSquirrel 0 65 50ms 25 Nov 2024 860th pardouin 🇫🇷 0 65 11ms 25 Nov 2024 860th btnlq 0 65 10ms 26 Nov 2024 860th CaedenHarper 🇨🇦 0 65 12ms 26 Nov 2024 860th emgordon154 0 65 10ms 26 Nov 2024 860th inventshah 0 65 11ms 26 Nov 2024 860th sean-niemann 🇺🇸 0 65 167ms 26 Nov 2024 860th stefangimmillaro 0 65 158ms 26 Nov 2024 860th duckyluuk 🇳🇱 0 65 10ms 26 Nov 2024 860th m-tkach 🇺🇦 0 65 11ms 26 Nov 2024 860th ovs-code 🇩🇪 0 65 2ms 26 Nov 2024 860th Alex-x90 🇺🇸 0 65 10ms 28 Nov 2024 First Prev 801–880 of 3,459 Next Last