The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 2 days. Why not try and solve them ahead of time?
12 Days of Christmas 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 560th BlankSpruce 657 505 136ms 25 Nov 2024 562nd NerdyMcNerd42 656 288 11ms 26 Oct 2022 562nd funnsam 🇭🇰 656 288 11ms 23 Oct 2023 564th emplv 🇱🇻 656 414 5ms 24 Aug 2023 565th the-zammers 655 483 121ms 10 Nov 2023 565th tobeannouncd 655 483 122ms 1 Jan 2024 567th cingulataluke 654 289 10ms 26 Aug 2023 568th chordowl 654 484 124ms 17 Mar 2021 569th RussellEmerine 653 485 119ms 1 Dec 2019 570th exodrifter 🇺🇸 651 486 111ms 25 Oct 2022 571st DaCuteRaccoon 651 588 1ms 2 Dec 2022 572nd jiaminglimjm 🇲🇾 650 291 10ms 12 Sep 2020 573rd MeWhenI 🇻🇦 650 470 118ms 8 Mar 2023 574th timvermeulen 649 511 168ms 4 Jan 2020 575th dokutan 649 539 1,022ms 15 Oct 2024 576th ListeriaM 649 607 2ms 27 Aug 2023 577th btjones0 648 512 161ms 26 Dec 2020 578th SmartK8 🇨🇿 646 379 435ms 26 Oct 2022 579th scpchicken 🇵🇼 646 514 251ms 19 May 2022 580th stefangimmillaro 646 610 2ms 14 Nov 2025 581st angel-p57 🇯🇵 646 2,506 2ms 30 Dec 2023 582nd mokymok 🇺🇸 645 293 16ms 23 Jul 2021 583rd yanqui-uxo 645 491 134ms 5 Sep 2018 584th mousetail 🇳🇱 644 494 5ms 29 Dec 2025 585th CarsonChr 🇺🇸 644 515 286ms 24 Dec 2023 585th tylerlaprade 644 515 172ms 13 Jun 2025 587th zhaohm14 643 294 10ms 28 May 2025 588th Matsuda12222 643 548 2ms 9 Jan 2025 589th agreegious 641 295 10ms 17 Mar 2025 590th zakariamouhid 641 336 10ms 18 May 2023 591st Shanethegamer 🇺🇸 641 476 368ms 22 Apr 2023 592nd MEAN-stack 641 494 119ms 8 Feb 2021 593rd NewDefectus 🇮🇱 641 546 25ms 1 Sep 2021 594th Santarii 640 495 119ms 7 Oct 2019 595th hacker112 🇸🇪 639 337 11ms 17 Jun 2024 596th edsrzf 🇳🇿 637 476 128ms 1 Dec 2025 597th makononov 637 521 185ms 28 Feb 2025 597th KasperKivimaeki 🇫🇮 637 521 166ms 7 Oct 2025 599th awnion 636 297 10ms 26 Dec 2020 599th Kyogre-Primal 🇺🇦 636 297 17ms 16 May 2025 599th Naitzirch 🇳🇱 636 297 10ms 3 Jul 2025 602nd MeWhenI 🇻🇦 636 522 212ms 13 Nov 2022 602nd vidanm 🇫🇷 636 522 196ms 11 Jun 2025 604th Irratix 🇳🇱 635 417 3,819ms 30 Dec 2022 605th chris-araman 635 481 104ms 3 Jan 2022 606th dokutan 634 268 77ms 12 Dec 2025 607th user189032 634 499 124ms 29 May 2019 608th GinjaNinja32 634 523 210ms 16 Apr 2020 609th edsrzf 🇳🇿 633 321 6ms 19 Feb 2025 610th yzhs 🇩🇪 633 500 123ms 24 Jul 2021 611th ridingqwerty 🇺🇸 633 552 15ms 11 Jul 2022 612th petar-donchev 632 299 9ms 7 Sep 2019 612th frankgraziano 632 299 10ms 6 Jan 2023 614th Shanethegamer 🇺🇸 632 525 183ms 11 Dec 2022 615th strout 631 502 121ms 15 Aug 2022 616th msbranicky 631 526 199ms 6 Oct 2023 616th dokutan 631 526 130ms 17 Oct 2024 618th o0lit3 🇺🇸 630 323 5ms 16 Apr 2021 618th primo-ppcg 🇹🇭 630 323 6ms 16 Apr 2021 620th primo-ppcg 🇹🇭 630 431 4ms 3 Jul 2023 621st MeWhenI 🇻🇦 630 505 6ms 13 Mar 2025 622nd orthoplex 🇨🇽 630 712 2ms 30 Sep 2020 623rd 0xEigenDev 629 560 2ms 28 Feb 2024 623rd rbertram90 🇬🇧 629 560 4ms 29 Dec 2025 625th icendoan 628 486 2ms 11 Aug 2024 625th kaascevich 628 486 122ms 8 Jul 2025 627th scottpenn 628 528 132ms 4 Jan 2020 628th wangchning 628 586 7ms 6 Jun 2023 629th GrayJoKing 🇦🇺 627 486 20ms 19 Nov 2021 630th Helam24 627 487 113ms 20 Jan 2020 631st Natanaelel 🇸🇪 627 505 114ms 11 Mar 2022 631st eddiesmithxyz 627 505 120ms 7 Jan 2023 633rd klixel 🇨🇦 627 529 160ms 4 Jun 2023 634th MeWhenI 🇻🇦 626 325 6ms 15 Oct 2021 634th lynn 626 325 5ms 25 Jan 2022 634th AlephSquirrel 626 325 6ms 4 Oct 2024 637th JOrE20 626 506 122ms 1 Nov 2025 638th yamhab 🇨🇦 626 530 144ms 13 Sep 2023 639th bluebear94 625 252 127ms 12 Feb 2018 640th dokutan 625 613 2ms 27 Feb 2025 First Prev 561–640 of 4,056 Next Last
