The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 24 hours. 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 801st henrytranter 436 219 14ms 1 Oct 2021 801st rschwa6308 🇺🇸 436 219 12ms 5 May 2023 801st yanjs 436 219 13ms 3 Jul 2025 804th perlebach 🇨🇿 435 149 3ms 3 Sep 2021 804th armin-k1 435 149 4ms 10 Sep 2021 806th mckymsh 435 195 13ms 4 Feb 2024 807th mdnestor 434 220 12ms 27 Dec 2022 808th elisherer 🇮🇱 433 196 11ms 28 Sep 2021 809th frosster 🇨🇦 433 216 2ms 19 Mar 2025 810th Yewzir 🇧🇪 433 260 627ms 24 Sep 2025 811th mokymok 🇺🇸 432 221 14ms 17 Nov 2021 811th hiichbindermax 432 221 12ms 5 Oct 2024 813th TRexOnGit 432 222 462ms 16 Jan 2024 813th SpareManiKatti 432 222 491ms 7 Apr 2025 815th ian-h-chamberlain 🇺🇸 432 315 172ms 30 Jun 2022 816th ComradeSquirrel 431 197 12ms 2 days ago 817th madex 🇩🇪 429 302 98ms 16 days ago 818th tomh1012 428 198 14ms 23 Aug 2021 818th acollett89 428 198 11ms 5 Aug 2025 820th lovernj 428 223 15ms 21 Jan 2022 820th Ailko 🇧🇪 428 223 11ms 5 May 2022 820th karhuthebear 428 223 14ms 11 May 2022 820th andre-lameirinhas 🇵🇹 428 223 13ms 26 Apr 2023 820th anarconic 428 223 13ms 7 Dec 2023 820th ffelixm 428 223 12ms 4 Jun 2025 820th Andrey2001 428 223 14ms 25 Nov 2025 827th msbranicky 428 295 3ms 11 Aug 2023 828th msbranicky 428 318 268ms 3 Oct 2023 829th BREMAUCY 🇫🇷 427 262 117ms 29 Dec 2025 830th sergioabreu-g 427 319 234ms 20 Jun 2025 831st CatsAreFluffy 426 199 13ms 30 Dec 2022 831st alexsave 426 199 13ms 16 Oct 2025 833rd SteveHales 426 208 113ms 20 Oct 2025 834th BobDotCom 426 224 14ms 25 Mar 2022 834th sleepyStick 426 224 13ms 14 Jul 2022 836th Jacob385 426 264 655ms 28 Oct 2025 837th tamanugi 🇯🇵 426 304 123ms 4 Nov 2022 838th 1231234md5 🇨🇳 424 225 14ms 15 Dec 2023 838th billythegoat356 424 225 14ms 5 Jun 2024 840th CaedenHarper 🇨🇦 422 200 182ms 23 Aug 2025 841st pineapplebox 422 201 13ms 1 Apr 2022 842nd trist224 🇫🇷 422 226 13ms 21 Feb 2023 843rd TylerBloom 421 323 194ms 21 Mar 2024 844th Mabeloid 🇳🇴 420 199 505ms 18 Sep 2024 845th abc7-12 420 205 2ms 2 Jun 2024 846th mothcolada 🇺🇸 420 227 13ms 8 Oct 2021 846th zt14427 420 227 14ms 28 Sep 2023 846th ballaire 420 227 14ms 27 Jan 2024 846th jatloe 420 227 14ms 23 Oct 2024 850th janAkali 🇷🇺 420 254 461ms 20 May 2024 851st cochrane 419 267 123ms 22 Mar 2024 852nd gbxdl 419 325 192ms 19 Jul 2022 853rd GeorgeStechman 🇬🇧 418 203 14ms 4 Dec 2023 853rd smclaughlin-cf 418 203 13ms 6 May 2025 855th tobyLovick 418 228 13ms 10 Dec 2023 855th mathisfun271 418 228 12ms 6 Mar 2024 855th Mefred 418 228 14ms 29 Oct 2025 858th MeWhenI 🇻🇦 417 148 49ms 15 Dec 2021 859th twocatsinatrenchcoat 417 229 13ms 14 Apr 2022 859th cthierfelder 🇲🇨 417 229 13ms 14 Nov 2025 859th tomh1012 417 229 11ms 18 Feb 2026 862nd MeWhenI 🇻🇦 417 337 6ms 25 Nov 2023 863rd EthanGrant1 415 230 14ms 10 Nov 2022 864th retrohun 415 257 379ms 27 days ago 865th blaztoma 🇱🇹 415 304 4ms 9 Nov 2025 866th zakariamouhid 414 205 11ms 22 Apr 2023 866th Protothor 414 205 11ms 10 days ago 868th MichaelMBradley 🇨🇦 413 231 22ms 27 Feb 2022 868th Florian-Mt 413 231 11ms 27 Nov 2023 868th l-donovan 413 231 13ms 6 Feb 2024 871st hamhub7 413 232 481ms 9 Aug 2022 872nd Ralac07 🇦🇺 412 206 13ms 24 Nov 2025 873rd Attero 🇸🇪 412 209 2ms 5 Aug 2022 874th jtaxen 411 232 15ms 21 May 2024 874th therealnumbers 411 232 13ms 29 Sep 2025 876th arcpolaris 411 233 558ms 14 Jan 2026 877th HumanoidCPU 410 207 13ms 23 Nov 2025 878th CaedenHarper 🇨🇦 409 225 164ms 25 Aug 2025 879th te-chnical 409 233 13ms 1 Jan 2026 880th madex 🇩🇪 409 309 3ms 16 days ago First Prev 801–880 of 1,320 Next Last