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?
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 321st GrayJoKing 🇦🇺 686 173 38ms 29 Apr 2024 322nd SirBogman 🇺🇸 685 54 54ms 16 Sep 2022 322nd emgordon154 685 54 52ms 2 Feb 2026 324th emplv 🇱🇻 685 138 5ms 1 Dec 2023 325th stefangimmillaro 684 183 371ms 15 Jul 2023 326th Vinterion 681 158 2ms 17 Jun 2024 327th MichalMarsalek 🇨🇿 681 194 588ms 5 Nov 2022 328th Irratix 🇳🇱 679 209 445ms 12 May 2022 329th Shanethegamer 🇺🇸 678 169 169ms 24 May 2025 330th m-tkach 🇺🇦 678 187 16ms 15 Jan 2025 331st MeWhenI 🇻🇦 677 158 118ms 23 Jun 2024 332nd lynn 677 263 32ms 23 Jul 2023 333rd FortuiteMan 🇫🇷 676 215 15ms 11 days ago 334th HPWiz 🇳🇿 675 120 32ms 21 May 2022 334th albanian-laundromat 675 120 18ms 12 Jul 2025 334th robin-scragg 675 120 17ms 3 Oct 2025 337th Shanethegamer 🇺🇸 675 213 9ms 4 Oct 2024 338th MeWhenI 🇻🇦 674 123 11ms 25 Nov 2022 339th Yewzir 🇧🇪 672 113 411ms 7 May 2024 340th lynn 669 120 1,237ms 3 Jun 2022 341st nwellnhof 🇩🇪 669 121 30ms 8 Jun 2022 342nd uttumuttu 🇫🇮 668 124 10ms 24 May 2022 342nd tayloia 🇬🇧 668 124 11ms 11 May 2023 344th DialFrost 🇸🇬 668 161 2ms 12 Feb 2024 345th SirBogman 🇺🇸 667 93 2ms 30 Oct 2022 345th retrohun 667 93 1ms 9 Nov 2022 347th AlephSquirrel 666 216 6ms 30 Oct 2024 348th nwellnhof 🇩🇪 663 82 127ms 20 May 2022 349th janbehrens 🇩🇪 663 189 453ms 3 Jul 2023 350th snoozingnewt 🇨🇦 661 148 116ms 22 Nov 2025 351st Alex-x90 🇺🇸 661 187 449ms 11 May 2024 352nd sean-niemann 🇺🇸 660 94 2ms 14 Aug 2023 353rd MeWhenI 🇻🇦 659 79 72ms 16 Aug 2022 354th Yax42 🇫🇷 659 190 477ms 30 Jul 2025 355th MeWhenI 🇻🇦 659 208 40ms 4 Sep 2024 356th FortuiteMan 🇫🇷 658 123 10ms 23 Aug 2023 357th elgan65536 🇺🇸 658 238 232ms 9 Mar 2024 358th adriweb 🇫🇷 657 160 27ms 21 Aug 2023 359th MeWhenI 🇻🇦 657 271 33ms 23 Jun 2024 360th stefangimmillaro 656 163 112ms 15 Jul 2023 361st Shanethegamer 🇺🇸 655 185 477ms 7 Jun 2022 362nd Shanethegamer 🇺🇸 655 190 147ms 12 May 2022 363rd MeWhenI 🇻🇦 654 189 438ms 23 Jun 2024 364th janAkali 🇷🇺 654 202 389ms 4 days ago 365th janbehrens 🇩🇪 653 217 356ms 3 Jul 2023 366th Sakisan 🇧🇪 652 127 11ms 12 May 2022 366th janbehrens 🇩🇪 652 127 12ms 3 Jul 2023 368th roavin 652 165 2ms 26 May 2022 369th CatsAreFluffy 650 190 66ms 30 Dec 2022 370th AlephSquirrel 649 57 52ms 26 Jun 2023 371st MeWhenI 🇻🇦 648 124 1,248ms 25 May 2022 372nd CatsAreFluffy 648 166 2ms 25 Jan 2023 372nd Alex-x90 🇺🇸 648 166 1ms 14 Dec 2023 374th itsh01 647 128 13ms 4 Jul 2022 375th Shanethegamer 🇺🇸 647 135 1,030ms 12 May 2022 376th ovs-code 🇩🇪 647 136 1,023ms 5 Jun 2024 377th snoozingnewt 🇨🇦 647 195 131ms 20 Nov 2025 378th MeWhenI 🇻🇦 647 204 403ms 26 Aug 2023 379th roavin 645 194 396ms 26 May 2022 380th inventshah 645 220 418ms 13 May 2022 381st Shanethegamer 🇺🇸 643 125 1,200ms 11 May 2022 381st stefangimmillaro 643 125 1,318ms 15 Jul 2023 383rd Shanethegamer 🇺🇸 643 147 5ms 11 May 2022 384th edsrzf 🇳🇿 643 213 40ms 30 Dec 2024 385th m-tkach 🇺🇦 642 273 65ms 7 Feb 2023 386th MeWhenI 🇻🇦 641 189 474ms 23 Jun 2024 387th prestosilver 🇺🇸 641 206 365ms 3 days ago 388th ovs-code 🇩🇪 640 85 122ms 23 May 2025 389th bac0id 640 193 449ms 29 Jun 2024 390th albanian-laundromat 639 132 1,321ms 19 Sep 2025 390th CaedenHarper 🇨🇦 639 132 1,600ms 6 Nov 2025 392nd blaztoma 🇱🇹 638 127 30ms 23 days ago 393rd edsrzf 🇳🇿 636 160 5ms 24 Jul 2025 394th ovs-code 🇩🇪 635 82 36ms 10 Jun 2024 395th GrayJoKing 🇦🇺 634 149 5ms 20 May 2022 395th DialFrost 🇸🇬 634 149 4ms 15 Jan 2024 397th scpchicken 🇵🇼 634 247 242ms 4 Feb 2023 398th KrausRaus 🇺🇸 633 131 14ms 12 May 2022 399th DialFrost 🇸🇬 633 139 7ms 1 Nov 2023 400th annaproxy 632 198 401ms 10 May 2022 First Prev 321–400 of 729 Next Last