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?
12 Days of Christmas in all languages in bytes. 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 Bytes Time Submitted 475th plcc0 900 456 9ms 31 Jan 2026 482nd MEAN-stack 900 494 119ms 8 Feb 2021 483rd SirBogman 🇺🇸 900 496 121ms 18 Jan 2020 484th MeWhenI 🇻🇦 900 531 40ms 3 Jul 2023 485th sean-niemann 🇺🇸 899 452 5ms 20 May 2025 486th jared-hughes 899 453 11ms 28 Mar 2022 486th madeforlosers 899 453 9ms 8 Nov 2023 488th dloscutoff 899 462 783ms 27 Nov 2018 489th Shanethegamer 🇺🇸 899 473 2,585ms 31 Oct 2024 490th Santarii 899 495 119ms 7 Oct 2019 491st scpchicken 🇵🇼 899 514 251ms 19 May 2022 492nd kusune 🇯🇵 898 412 2ms 29 Sep 2023 493rd jared-hughes 898 434 31ms 20 Sep 2022 494th Haksell 🇦🇶 898 457 10ms 4 Feb 2021 494th solisolu 898 457 10ms 21 days ago 496th DaCuteRaccoon 897 444 257ms 1 Oct 2022 496th DialFrost 🇸🇬 897 444 261ms 7 Jan 2023 496th PowershellKnut 🇳🇴 897 444 286ms 13 Jan 2023 496th Jaykul 897 444 259ms 29 Apr 2024 496th 5quiwyrm 897 444 301ms 2 Sep 2025 501st MeWhenI 🇻🇦 897 453 5ms 3 Jul 2023 502nd tayloia 🇬🇧 897 454 13ms 12 Jan 2023 502nd lukegustafson 🇺🇸 897 454 9ms 7 Dec 2023 502nd emgordon154 897 454 9ms 10 Aug 2024 505th Shanethegamer 🇺🇸 897 469 160ms 28 Jul 2021 506th CarsonChr 🇺🇸 897 515 286ms 24 Dec 2023 506th tylerlaprade 897 515 172ms 13 Jun 2025 508th primo-ppcg 🇹🇭 896 413 2ms 9 Nov 2021 509th jaredcrystal 🇺🇸 896 435 32ms 15 Dec 2020 510th lordnord 896 458 10ms 2 May 2020 510th davitf 896 458 10ms 7 May 2020 510th knutae 🇳🇴 896 458 9ms 9 Feb 2022 510th M0PKOBKA 896 458 9ms 27 Dec 2022 510th drochom 896 458 10ms 16 Jun 2024 510th fourth-bit 896 458 10ms 25 Sep 2024 516th MeWhenI 🇻🇦 896 471 4ms 22 May 2023 517th Shanethegamer 🇺🇸 896 472 530ms 31 Oct 2024 518th MeWhenI 🇻🇦 896 475 2,925ms 24 Oct 2024 519th msbranicky 896 498 97ms 15 Sep 2023 520th SirBogman 🇺🇸 896 515 286ms 5 Oct 2020 520th sean-niemann 🇺🇸 896 515 291ms 6 May 2024 522nd KatieLG 🇬🇧 896 528 2ms 6 Mar 2021 523rd skrivy 895 454 4ms 31 Oct 2020 524th omurakazuaki 🇯🇵 895 455 10ms 21 Sep 2019 524th SubsTheTechnomancer 895 455 11ms 2 Mar 2023 524th neel11235813 895 455 10ms 26 Mar 2024 527th Sp3000 🇦🇺 895 473 5ms 29 May 2021 528th jared-hughes 895 489 1ms 29 Mar 2022 529th ccbrown 895 516 289ms 18 Apr 2020 529th cloudyshoe 895 516 293ms 20 May 2025 531st KatieLG 🇬🇧 894 436 36ms 10 Apr 2022 531st SirBogman 🇺🇸 894 436 35ms 8 Dec 2023 531st neel11235813 894 436 35ms 26 Mar 2024 534th magnickolas 894 459 10ms 30 Aug 2020 534th Shanethegamer 🇺🇸 894 459 10ms 11 Mar 2022 534th QuincyNash 🇺🇸 894 459 10ms 29 Nov 2022 534th keelimeguy 🇺🇸 894 459 30ms 25 Dec 2023 534th Liniarc 894 459 9ms 21 Nov 2024 534th cefqrn 894 459 9ms 18 Jan 2025 534th dirckvdende 894 459 10ms 29 Jun 2025 541st peeveen 🇬🇧 894 474 390ms 8 Sep 2023 542nd sean-niemann 🇺🇸 894 476 2,632ms 11 Nov 2025 543rd DialFrost 🇸🇬 894 483 82ms 19 Feb 2025 544th msbranicky 894 497 1ms 20 Jan 2025 545th namelessiw 894 511 451ms 6 Oct 2025 545th kmathis22 894 511 526ms 14 Oct 2025 547th ovs-code 🇩🇪 893 439 7ms 16 Mar 2023 547th GolfingSuccess 🇬🇷 893 439 8ms 26 Mar 2023 549th ryanlanegit 893 446 269ms 23 Jun 2022 550th KatieLG 🇬🇧 893 451 1,271ms 29 Aug 2024 551st taimanh229 893 456 11ms 30 Dec 2020 551st Liniarc 893 456 10ms 21 Nov 2024 553rd SubsTheTechnomancer 893 517 286ms 6 Mar 2023 553rd snoozingnewt 🇨🇦 893 517 287ms 23 Sep 2023 553rd neel11235813 893 517 294ms 26 Mar 2024 556th GrayJoKing 🇦🇺 892 404 128ms 8 Dec 2020 557th kg583 🇺🇸 892 450 492ms 5 Feb 2026 558th marcin7Cd 892 460 9ms 11 Dec 2020 558th RYNO8 892 460 10ms 29 Aug 2021 558th lucasvazq 🇦🇷 892 460 9ms 20 Mar 2022 First Prev 481–560 of 4,082 Next Last