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?
Forsyth–Edwards Notation 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 720th yokasuretsu 412 198 10ms 14 Jan 2025 722nd stephanie-flower 408 235 10ms 2 Nov 2025 723rd SirFireball3521 407 132 165ms 26 Feb 2024 724th DrPrettyman 405 201 10ms 25 May 2023 724th mrmena 🇦🇺 405 201 10ms 29 Mar 2024 726th Maashau 405 240 2ms 15 Dec 2025 727th m42km 403 202 10ms 3 Feb 2024 728th Widgitty 403 241 2ms 23 Sep 2025 729th ridingqwerty 🇺🇸 401 203 10ms 30 Jan 2024 729th Andrey2001 401 203 10ms 1 Feb 2026 729th tomh1012 401 203 16ms 26 days ago 732nd FortuiteMan 🇫🇷 400 204 16ms 11 Jul 2025 733rd AbuzarN 398 205 17ms 22 Nov 2023 734th apokryfos 398 241 9ms 20 Aug 2023 735th galloj 🇨🇿 396 206 14ms 8 May 2023 736th jameswmccarty 394 207 10ms 6 Apr 2025 737th dokutan 390 318 3ms 7 Dec 2024 738th MeWhenI 🇻🇦 388 412 2ms 1 May 2023 739th KatieLG 🇬🇧 387 192 4ms 1 May 2023 740th ellis-rix 386 211 11ms 11 May 2023 741st dokutan 385 249 10ms 29 Mar 2025 742nd ridingqwerty 🇺🇸 383 198 556ms 22 Jan 2024 743rd ItsMeNoobieboy 381 214 10ms 6 May 2023 744th MeWhenI 🇻🇦 379 430 63ms 1 May 2023 745th yuchuehw 378 352 481ms 3 Jan 2024 746th fischfood 377 277 5ms 15 Aug 2024 747th liviucerchez 371 282 5ms 14 Oct 2023 748th kzheng808 369 221 9ms 14 Jun 2023 749th dokutan 367 684 12ms 28 Jun 2025 750th snoozingnewt 🇨🇦 365 147 163ms 31 Oct 2025 751st epic-programmer-guy 365 223 10ms 1 Jan 2024 752nd dokutan 365 437 2ms 29 Jun 2025 753rd MyXoToD 🇩🇪 364 263 9ms 1 Jul 2024 754th Yewzir 🇧🇪 358 210 815ms 5 Apr 2024 755th dokutan 354 357 406ms 23 Sep 2024 756th jtaxen 350 233 9ms 26 Apr 2024 757th KatieLG 🇬🇧 349 281 394ms 19 Oct 2024 758th MassimoParisi 347 235 11ms 20 Sep 2024 759th dokutan 347 377 2ms 29 Mar 2025 760th dokutan 346 217 801ms 7 Apr 2024 761st cmccandless 341 239 10ms 16 Oct 2023 762nd Blockyheadman 340 336 72ms 5 Nov 2025 763rd mrmena 🇦🇺 338 375 41ms 16 Apr 2024 764th MeWhenI 🇻🇦 333 287 2ms 18 Nov 2023 765th dokutan 333 345 65ms 12 Mar 2025 766th puffertron 331 246 10ms 10 Jan 2024 766th ComputerKWasTaken 🇺🇸 331 246 10ms 21 Jan 2025 768th Jacob-Gendelman 330 247 10ms 27 Jul 2023 768th OCNeve 330 247 10ms 18 Jun 2024 770th MeWhenI 🇻🇦 327 462 305ms 1 May 2023 771st MamoonUddin 325 251 10ms 3 Dec 2024 772nd jalbertgordon 321 254 10ms 23 Oct 2023 773rd dokutan 320 357 467ms 8 Nov 2025 774th MeWhenI 🇻🇦 318 361 538ms 1 Nov 2023 775th cingulataluke 317 257 10ms 27 Aug 2023 776th dokutan 315 262 1,023ms 5 Feb 2025 777th dokutan 313 174 2ms 13 Nov 2024 778th MeWhenI 🇻🇦 313 411 152ms 1 May 2023 779th dokutan 312 484 275ms 19 Oct 2024 780th dokutan 311 463 1,357ms 14 Oct 2024 781st alfonsoalves 308 265 10ms 26 Feb 2024 782nd aksyristos 306 201 39ms 28 Oct 2024 783rd alecdavidson 306 266 15ms 9 Jun 2023 784th bwat2 305 436 412ms 11 May 2023 785th sojumasterGA 297 241 274ms 2 May 2023 786th zt14427 296 275 10ms 11 Feb 2025 787th dokutan 294 453 382ms 24 Sep 2025 788th dokutan 292 333 2ms 8 Nov 2025 789th Bananapants22 291 280 10ms 13 May 2023 790th dokutan 289 269 914ms 29 Aug 2025 791st dokutan 288 285 129ms 23 Sep 2024 792nd TimSvensson 287 284 10ms 5 Nov 2023 793rd dylanjones92 282 289 10ms 17 Jan 2024 794th dokutan 280 353 2,762ms 25 Oct 2024 795th meenie 277 222 35ms 1 May 2023 796th eli-siegel 277 567 280ms 23 Jun 2023 797th MarkE0 276 259 299ms 28 Apr 2024 798th dokutan 275 347 2ms 30 Jul 2024 799th dokutan 274 469 591ms 7 Nov 2025 800th Apataras 269 495 444ms 29 Jun 2025 First Prev 721–800 of 854 Next Last