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?
Set 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 321st ovs-code 🇩🇪 608 120 1,666ms 17 Apr 2025 322nd snoozingnewt 🇨🇦 607 217 152ms 20 Nov 2025 323rd kmathis22 607 265 495ms 11 Oct 2025 324th Salutations45 606 139 93ms 12 Apr 2025 325th Shanethegamer 🇺🇸 606 152 46ms 6 Apr 2025 326th CornerMercury 🇬🇧 604 123 439ms 4 Nov 2025 327th mousetail 🇳🇱 604 133 20ms 3 Apr 2025 327th jtaxen 604 133 27ms 20 Oct 2025 329th namelessiw 602 191 531ms 1 Aug 2025 330th ImpressedByRocks 600 134 27ms 29 Apr 2025 331st error256 600 163 32ms 15 Apr 2025 332nd DialFrost 🇸🇬 600 268 387ms 24 Sep 2025 333rd HumanoidCPU 599 124 473ms 29 Mar 2025 333rd FEZfan 🇦🇺 599 124 566ms 26 Apr 2025 335th madex 🇩🇪 595 135 27ms 13 Feb 2025 335th KasperKivimaeki 🇫🇮 595 135 29ms 3 Jul 2025 335th amberzit 595 135 25ms 6 Jul 2025 335th aksyristos 595 135 27ms 27 hours ago 339th albanian-laundromat 591 342 28ms 16 days ago 340th DialFrost 🇸🇬 590 126 514ms 18 Feb 2025 341st rucin93 🇵🇱 589 124 180ms 9 May 2025 342nd h3ra993huskp 🇯🇵 587 274 520ms 30 Nov 2025 343rd snoozingnewt 🇨🇦 587 306 305ms 30 Oct 2025 344th MeWhenI 🇻🇦 585 127 549ms 25 Jun 2025 345th m-tkach 🇺🇦 585 263 42ms 8 May 2025 346th denkyuu1 584 85 94ms 4 days ago 347th CaedenHarper 🇨🇦 579 143 1,254ms 2 Oct 2025 348th AlephSquirrel 579 234 496ms 1 Apr 2025 349th emgordon154 574 133 1,055ms 14 May 2025 350th hiichbindermax 574 140 20ms 22 May 2025 350th Artemis21 🇬🇧 574 140 31ms 23 May 2025 350th andrewjc2000 574 140 25ms 15 Jul 2025 350th CaedenHarper 🇨🇦 574 140 32ms 29 Jul 2025 354th mousetail 🇳🇱 572 272 270ms 27 Mar 2025 355th dirckvdende 570 141 34ms 10 Jul 2025 356th edsrzf 🇳🇿 570 199 212ms 29 Nov 2025 357th targrik 569 158 58ms 7 May 2025 358th emgordon154 569 388 1,676ms 17 Sep 2025 359th stefangimmillaro 568 280 44ms 7 May 2025 360th zt14427 566 142 25ms 20 Apr 2025 361st Shanethegamer 🇺🇸 565 159 34ms 30 Mar 2025 361st alexsave 565 159 90ms 20 Jan 2026 363rd MeWhenI 🇻🇦 564 391 1,872ms 18 Nov 2025 364th snoozingnewt 🇨🇦 560 136 1,313ms 30 Oct 2025 365th DanielVenable 558 161 15ms 26 Mar 2025 366th moustave 554 145 32ms 16 Apr 2025 366th za3k 554 145 33ms 17 Apr 2025 368th olleicua 🇺🇸 552 90 58ms 22 Apr 2025 369th Bmrl7 551 146 24ms 25 Dec 2025 369th nemoyatpeace 551 146 26ms 19 Jan 2026 371st Salutations45 551 163 21ms 11 Apr 2025 372nd MeWhenI 🇻🇦 549 240 527ms 5 Apr 2025 373rd CaedenHarper 🇨🇦 547 136 508ms 4 Apr 2025 374th snoozingnewt 🇨🇦 543 209 128ms 7 Dec 2025 375th SirBogman 🇺🇸 542 145 3,991ms 5 Jul 2025 376th Jacob385 541 297 436ms 31 Mar 2025 377th SirBogman 🇺🇸 540 92 53ms 19 Jul 2025 377th TheZwierzLF 🇵🇱 540 92 53ms 5 Jan 2026 379th Chinay-Domitrix 🇺🇸 540 188 2,754ms 28 Mar 2025 380th Ripick 539 237 400ms 24 Apr 2025 381st ShiraJoseph 🇺🇸 538 167 17ms 26 Apr 2025 382nd JDiLenarda 🇫🇷 537 264 1,406ms 7 Apr 2025 383rd Andriamanitra 🇫🇮 532 151 30ms 29 Mar 2025 384th klixel 🇨🇦 529 152 347ms 5 Apr 2025 385th tayloia 🇬🇧 529 170 15ms 7 Apr 2025 386th annaproxy 521 221 424ms 2 Apr 2025 386th tomh1012 521 221 506ms 26 Aug 2025 388th snoozingnewt 🇨🇦 518 286 64ms 30 Oct 2025 389th emgordon154 517 96 60ms 27 Mar 2025 390th mousetail 🇳🇱 513 247 2ms 28 Mar 2025 391st Shanethegamer 🇺🇸 512 97 62ms 13 Feb 2025 392nd FortuiteMan 🇫🇷 512 157 19ms 20 Jun 2025 393rd jared-hughes 511 176 20ms 6 Apr 2025 393rd Sakisan 🇧🇪 511 176 143ms 11 Apr 2025 395th snoozingnewt 🇨🇦 511 248 119ms 30 Oct 2025 396th FEZfan 🇦🇺 510 250 38ms 22 Apr 2025 397th calebaitken 506 159 25ms 10 Apr 2025 397th Yewzir 🇧🇪 506 159 20ms 17 Nov 2025 399th snoozingnewt 🇨🇦 505 253 456ms 30 Oct 2025 400th BREMAUCY 🇫🇷 502 99 61ms 4 Nov 2025 First Prev 321–400 of 490 Next Last