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?
Morse Encoder 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 400th Lv0Sys 🇵🇱 534 204 10ms 30 Nov 2025 402nd stefangimmillaro 533 175 10ms 29 Dec 2022 403rd elisherer 🇮🇱 532 205 12ms 13 Apr 2019 404th SirBogman 🇺🇸 530 163 518ms 20 Jan 2024 405th Lv0Sys 🇵🇱 530 176 10ms 30 Nov 2025 406th tdkkdt 🇷🇺 530 201 452ms 21 Nov 2021 407th janbehrens 🇩🇪 528 165 238ms 13 Jul 2022 408th KatieLG 🇬🇧 528 193 1,571ms 25 Apr 2021 409th BisheruBlade888 527 257 58ms 14 Jan 2022 409th MeWhenI 🇻🇦 527 257 443ms 7 May 2023 411th bluebear94 524 139 142ms 2 Mar 2018 412th benwilliamgraham 524 178 10ms 26 Jan 2019 413th MeWhenI 🇻🇦 522 516 7ms 28 Nov 2023 414th annaproxy 521 179 10ms 22 Feb 2023 414th 5quiwyrm 521 179 10ms 28 Jan 2026 416th JOrE20 519 210 13ms 4 Feb 2026 417th abailey2020 🇺🇸 518 180 10ms 18 Aug 2020 417th ydevor 🇮🇱 518 180 11ms 16 Feb 2021 417th Omega65536 🇩🇪 518 180 10ms 10 Aug 2025 417th robin-scragg 518 180 10ms 18 Oct 2025 421st dokutan 518 199 3,370ms 6 Nov 2024 422nd BREMAUCY 🇫🇷 515 207 427ms 20 Jan 2023 423rd alexsave 514 212 11ms 14 Dec 2025 424th MeWhenI 🇻🇦 514 594 11ms 10 Feb 2025 425th didroe 513 157 37ms 20 Nov 2024 426th violeta-desantis 513 235 2ms 17 Apr 2024 427th dzhang314 512 182 17ms 15 Aug 2019 427th davecame 512 182 11ms 22 Nov 2023 429th commandz0 🇺🇸 511 169 966ms 1 Sep 2025 430th c0d3-4-F00d 🇩🇪 511 236 2ms 5 Jun 2023 431st commandz0 🇺🇸 510 183 17ms 30 Apr 2023 432nd MeWhenI 🇻🇦 509 221 3ms 25 Dec 2025 433rd gastropner 509 237 2ms 25 Dec 2020 434th emgordon154 509 280 4ms 28 Dec 2024 435th Lv0Sys 🇵🇱 507 159 35ms 30 Nov 2025 436th NewDefectus 🇮🇱 507 184 10ms 1 Nov 2021 436th janbehrens 🇩🇪 507 184 10ms 17 Jun 2023 436th Troon 507 184 10ms 18 Apr 2025 439th mtirado1 506 292 2ms 7 May 2023 440th janbehrens 🇩🇪 505 255 3ms 9 Jun 2021 441st qpwoeirut 504 185 10ms 20 Oct 2025 442nd dokutan 501 174 591ms 6 Nov 2024 443rd quimey 501 186 12ms 17 Jul 2023 443rd BREMAUCY 🇫🇷 501 186 10ms 21 Aug 2025 445th scpchicken 🇵🇼 500 213 448ms 6 Apr 2022 446th skps2010 500 218 9ms 29 Dec 2018 446th raphaelimahorn 500 218 11ms 18 Aug 2021 448th CedricGebistorf 499 187 10ms 4 Mar 2022 448th pyrolitic 🇮🇪 499 187 19ms 6 Apr 2022 448th ahmetdemirag 🇨🇾 499 187 10ms 19 Nov 2024 451st FortuiteMan 🇫🇷 496 188 11ms 18 Dec 2025 452nd MichalMarsalek 🇨🇿 494 309 439ms 4 Sep 2022 453rd snoozingnewt 🇨🇦 494 315 2ms 9 Nov 2025 454th bricknellj 493 701 2ms 3 May 2024 455th SniperSmiley 🇺🇸 491 190 11ms 23 Jun 2021 456th ArmaanAS 491 222 17ms 25 Mar 2021 457th KatieLG 🇬🇧 488 165 36ms 10 Apr 2022 458th Informagier 488 191 18ms 16 Sep 2020 459th guliyevemil1 🇦🇿 486 332 327ms 18 Apr 2020 460th dloscutoff 484 180 754ms 23 Nov 2018 461st janAkali 🇷🇺 484 315 388ms 10 Sep 2024 462nd PatrickStephansen 🇿🇦 483 193 17ms 23 Aug 2023 463rd bwat2 483 287 502ms 10 Feb 2022 464th ToriTheChicken 480 227 14ms 2 Aug 2020 465th rvdnieuwendijk 🇳🇱 478 193 298ms 26 Jun 2020 466th RaBa21 🇭🇺 478 195 17ms 14 Jul 2025 467th Mabeloid 🇳🇴 476 196 10ms 21 Sep 2024 468th emgordon154 474 170 35ms 20 Aug 2024 469th m-tkach 🇺🇦 471 198 11ms 13 Feb 2023 470th kevinmchung 469 199 18ms 24 Feb 2018 471st SB-945 466 200 18ms 4 Sep 2023 471st Jacob385 466 200 13ms 1 May 2024 473rd annaproxy 466 229 421ms 3 May 2022 474th StefanHabel 🇨🇦 464 201 10ms 19 days ago 475th coreynash 464 235 11ms 28 May 2024 476th sambirnbaum1 462 202 10ms 13 Oct 2019 477th dokutan 460 175 38ms 23 Apr 2025 478th Yewzir 🇧🇪 459 321 8ms 26 Dec 2024 479th Lv0Sys 🇵🇱 456 191 245ms 30 Nov 2025 480th davitf 453 206 11ms 31 Oct 2018 First Prev 401–480 of 1,003 Next Last