The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 6 days. Why not try and solve them ahead of time?
Jacobi Symbol 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 401st targrik 630 150 7ms 24 Jan 2025 402nd CaedenHarper 🇨🇦 629 199 362ms 17 Oct 2025 403rd primo-ppcg 🇹🇭 628 182 91ms 28 May 2022 404th yzhs 🇩🇪 628 198 143ms 23 Jun 2022 405th SirBogman 🇺🇸 627 83 36ms 14 May 2022 405th janlelis 627 83 61ms 21 Sep 2024 407th AlephSquirrel 627 121 427ms 21 Jan 2024 408th Ripick 626 211 392ms 18 Aug 2024 409th bac0id 625 172 1ms 29 Jun 2024 410th AlephSquirrel 623 130 30ms 21 Jul 2022 411th stefangimmillaro 623 133 13ms 19 Sep 2024 412th tomh1012 623 201 440ms 13 days ago 413th edsrzf 🇳🇿 623 212 405ms 23 Jul 2025 414th janbehrens 🇩🇪 622 152 5ms 3 Jul 2023 415th GrayJoKing 🇦🇺 621 106 3ms 20 May 2022 416th DialFrost 🇸🇬 619 251 2ms 26 May 2024 417th CaedenHarper 🇨🇦 618 134 10ms 6 Nov 2025 418th c0d3-4-F00d 🇩🇪 615 175 2ms 23 May 2022 419th Yewzir 🇧🇪 614 345 1,685ms 24 May 2024 420th IanUtley 613 188 120ms 15 Nov 2023 421st nwellnhof 🇩🇪 612 85 35ms 20 May 2022 422nd dokutan 612 224 41ms 31 Aug 2024 423rd inventshah 611 128 237ms 6 Nov 2022 424th SirBogman 🇺🇸 610 419 18ms 27 Dec 2023 425th zakariamouhid 609 136 12ms 11 May 2023 425th gigaprofisi 🇺🇸 609 136 11ms 10 Aug 2025 427th GolfingSuccess 🇬🇷 607 61 51ms 14 Aug 2022 428th anter69 🇭🇺 605 86 62ms 13 Feb 2024 429th anter69 🇭🇺 604 133 1,239ms 16 Feb 2023 430th Natanaelel 🇸🇪 604 206 135ms 9 May 2022 430th annaproxy 604 206 142ms 3 Jun 2022 432nd SirBogman 🇺🇸 604 235 1,404ms 26 May 2022 433rd annaproxy 603 191 20ms 23 Oct 2022 434th MeWhenI 🇻🇦 602 165 10ms 16 Aug 2024 435th stefangimmillaro 602 213 44ms 15 Jul 2023 436th MeWhenI 🇻🇦 602 239 7ms 23 Jun 2024 437th klixel 🇨🇦 602 260 225ms 9 Jun 2023 438th tobeannouncd 601 207 137ms 2 Jan 2024 439th MeWhenI 🇻🇦 600 117 8ms 18 May 2022 440th 5cw 🇺🇸 600 135 12ms 4 May 2025 440th Babafaba 600 135 17ms 7 Sep 2025 442nd SirBogman 🇺🇸 600 192 117ms 6 Oct 2025 443rd jared-hughes 597 106 21ms 19 Jul 2022 444th MeWhenI 🇻🇦 596 215 41ms 23 Jun 2024 445th ryyyn 🇺🇸 595 136 31ms 15 Jan 2026 446th emgordon154 595 167 15ms 27 Aug 2024 447th amazingalek 🇳🇴 593 211 427ms 26 Jan 2026 448th GrayJoKing 🇦🇺 591 88 36ms 25 Oct 2023 449th hamhub7 591 212 399ms 8 Aug 2022 450th inventshah 589 129 511ms 21 Jan 2024 451st dokutan 589 181 13ms 1 Jul 2024 452nd lynn 587 138 10ms 4 Jun 2022 453rd Yewzir 🇧🇪 585 202 278ms 27 Oct 2023 454th SirBogman 🇺🇸 585 219 44ms 4 Nov 2024 455th fantaize 584 268 203ms 15 days ago 456th Yewzir 🇧🇪 582 215 420ms 22 Dec 2024 457th retrohun 581 109 13ms 12 Oct 2024 458th eranws 579 143 15ms 23 Oct 2022 458th AlephSquirrel 579 143 12ms 21 Dec 2022 460th Shanethegamer 🇺🇸 578 90 35ms 12 May 2022 461st jared-hughes 578 140 10ms 19 Jul 2022 462nd DialFrost 🇸🇬 576 178 2ms 29 Jan 2024 463rd rifatx 576 205 307ms 23 Jul 2024 464th two-bad 🇬🇧 575 144 11ms 9 Feb 2024 465th Yewzir 🇧🇪 575 215 2,838ms 7 May 2024 466th emgordon154 574 140 1,300ms 25 Nov 2024 467th cingulataluke 574 141 11ms 27 Aug 2023 467th MeWhenI 🇻🇦 574 141 10ms 22 May 2024 467th bizy-coder 574 141 29ms 27 Nov 2025 470th msbranicky 572 274 258ms 1 Oct 2023 471st GolfingSuccess 🇬🇷 571 133 594ms 20 Jan 2024 472nd Yewzir 🇧🇪 571 297 18ms 22 Dec 2024 473rd MeWhenI 🇻🇦 571 307 56ms 23 Jun 2024 474th GolfingSuccess 🇬🇷 570 142 10ms 21 May 2022 475th MeWhenI 🇻🇦 569 166 5ms 28 May 2023 476th SirBogman 🇺🇸 569 185 2ms 21 May 2022 477th coreynash 568 146 10ms 19 Oct 2023 477th alexsave 568 146 13ms 15 Nov 2025 479th janbehrens 🇩🇪 567 138 292ms 12 May 2022 480th martinnorling 🇸🇪 566 124 9ms 13 May 2022 First Prev 401–480 of 728 Next Last