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?
Arrows 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 641st inventshah 524 351 7ms 30 Dec 2022 642nd Bmrl7 521 183 14ms 29 Mar 2024 642nd paiv 521 183 13ms 16 Jun 2025 644th angel-p57 🇯🇵 521 516 2ms 21 Nov 2023 645th georgehulme 518 184 13ms 5 Oct 2022 645th jeff-at-tamer-dot-codes 🇺🇸 518 184 11ms 28 Jul 2024 645th ComradeSquirrel 518 184 11ms 2 hours ago 648th dokutan 517 132 271ms 4 Feb 2026 649th moikaturns 🇬🇧 517 164 13ms 10 Nov 2022 649th unfinishedprogram 517 164 14ms 26 Oct 2023 651st ian-h-chamberlain 🇺🇸 517 319 54ms 2 Nov 2025 652nd alexjurkiewicz 🇦🇺 516 185 11ms 7 Nov 2023 653rd eMGeeneer 514 219 648ms 26 Jun 2024 654th NicoAdams 513 186 15ms 25 Nov 2021 655th BREMAUCY 🇫🇷 513 208 428ms 26 Dec 2025 656th namelessiw 510 164 611ms 5 Mar 2024 657th Kanawanagasaki 510 188 419ms 15 Sep 2022 658th eMGeeneer 509 215 583ms 27 Jun 2024 659th StardustGogeta 507 188 13ms 6 May 2023 659th zbreit 🇺🇸 507 188 14ms 6 May 2023 661st ericlangedijk 🇸🇮 507 189 445ms 12 Mar 2022 662nd MeWhenI 🇻🇦 507 485 10ms 28 Nov 2023 663rd Yewzir 🇧🇪 506 256 135ms 1 Dec 2025 664th Haksell 🇦🇶 505 136 36ms 22 Feb 2023 665th itserasmus 505 168 16ms 25 Jan 2024 666th xiaoyiming123 505 189 11ms 24 Jul 2025 667th KatieLG 🇬🇧 502 169 13ms 13 Aug 2022 667th ToriTheChicken 502 169 16ms 30 May 2023 669th aaronze 🇦🇺 501 137 38ms 17 Sep 2023 670th janbehrens 🇩🇪 499 130 3ms 17 Jun 2023 671st stefangabos 🇷🇴 499 170 12ms 15 Sep 2022 671st weliveinhell 🇭🇹 499 170 14ms 2 Oct 2023 673rd PhysicDev 🇫🇷 499 191 14ms 4 Oct 2022 673rd FranklinJiaChen 499 191 11ms 12 Jun 2024 675th rowboat1 497 192 14ms 11 Jun 2022 675th TaserTheFox 🇺🇸 497 192 14ms 3 Jan 2023 675th PaulMWeiser 497 192 14ms 8 Mar 2023 675th CaedenHarper 🇨🇦 497 192 15ms 18 Jan 2025 679th IanUtley 497 241 21ms 14 May 2024 680th retrohun 497 370 4ms 15 Nov 2025 681st trinityy-7 496 171 14ms 17 Jul 2023 682nd BREMAUCY 🇫🇷 495 255 3ms 26 Dec 2025 683rd janbehrens 🇩🇪 494 138 335ms 1 Nov 2021 684th martinnorling 🇸🇪 494 193 14ms 25 Feb 2022 684th aazuspan 494 193 14ms 8 Aug 2022 684th roguh 🇬🇹 494 193 14ms 22 Jan 2024 687th Maznek 493 172 14ms 14 Jun 2023 687th 4very 493 172 13ms 10 Jun 2025 689th snoozingnewt 🇨🇦 492 116 135ms 10 Dec 2025 690th bobbysq 492 194 13ms 10 May 2023 690th cros107 🇦🇺 492 194 17ms 9 Aug 2023 690th Mikey-Beep 🇬🇧 492 194 14ms 25 Aug 2023 693rd KatieLG 🇬🇧 491 241 4ms 30 Oct 2021 694th strout 491 303 171ms 15 Aug 2022 695th setop 489 195 14ms 18 Aug 2023 695th slimer37 489 195 14ms 6 Dec 2025 697th varhammer 488 288 9ms 13 Dec 2023 698th igmcdowell 487 174 15ms 14 Nov 2021 699th smartiel 487 196 44ms 18 Sep 2022 699th PyryL 🇫🇮 487 196 12ms 21 Aug 2024 701st ShiraJoseph 🇺🇸 485 175 14ms 7 May 2022 702nd knutae 🇳🇴 484 197 15ms 29 Oct 2021 702nd btjones0 484 197 13ms 4 Dec 2021 702nd RDShah 484 197 13ms 8 Jun 2022 702nd QuincyNash 🇺🇸 484 197 13ms 6 Dec 2022 702nd HumanoidCPU 484 197 14ms 31 Oct 2024 702nd yokasuretsu 484 197 13ms 4 Jan 2025 702nd RobertHoeh 484 197 12ms 3 Mar 2025 702nd gamk3 484 197 14ms 6 May 2025 710th dokutan 484 261 3ms 5 Feb 2025 711th btjones0 483 282 258ms 8 Dec 2021 712th iliazeus 482 176 15ms 4 Sep 2022 713th DrPrettyman 482 198 14ms 12 Jul 2023 713th jacekwladzinski 482 198 11ms 8 Oct 2025 715th KatieLG 🇬🇧 482 262 3ms 8 Nov 2025 716th scpchicken 🇵🇼 481 283 221ms 6 Apr 2022 717th rvs314 480 143 38ms 24 Sep 2024 717th denkyuu1 480 143 44ms 16 Feb 2026 719th rgthree 479 177 13ms 6 Sep 2023 720th asheeri 479 199 14ms 23 Aug 2021 First Prev 641–720 of 1,329 Next Last