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?
Roman to Arabic 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 480th edsrzf 🇳🇿 824 118 41ms 12 Nov 2025 482nd blaztoma 🇱🇹 823 70 44ms 22 Nov 2025 483rd alemelis 822 75 601ms 16 Feb 2024 484th GrayJoKing 🇦🇺 822 136 328ms 4 Dec 2020 485th MeWhenI 🇻🇦 822 154 325ms 17 Apr 2023 486th lifthrasiir 🇰🇷 822 221 193ms 19 Dec 2024 487th MeWhenI 🇻🇦 821 74 1,089ms 28 Jan 2023 488th emplv 🇱🇻 821 96 29ms 28 Nov 2022 489th Shanethegamer 🇺🇸 821 114 21ms 6 Nov 2023 490th MeWhenI 🇻🇦 820 94 659ms 13 Feb 2025 491st m-tkach 🇺🇦 820 150 94ms 6 Dec 2022 492nd primo-ppcg 🇹🇭 819 120 1,420ms 24 Oct 2021 493rd akshatj27 🇦🇶 818 93 16ms 11 Jan 2022 493rd duckyluuk 🇳🇱 818 93 15ms 9 Oct 2024 495th AlephSquirrel 818 98 35ms 21 Oct 2024 496th DialFrost 🇸🇬 816 289 51ms 13 Aug 2025 496th frankgraziano 816 289 88ms 13 Oct 2025 498th Shanethegamer 🇺🇸 815 76 142ms 12 Dec 2021 499th MeWhenI 🇻🇦 814 126 594ms 7 Nov 2025 500th MeWhenI 🇻🇦 814 200 1,774ms 7 Nov 2025 501st GrayJoKing 🇦🇺 813 111 18ms 3 Dec 2023 502nd dokutan 812 71 39ms 7 Apr 2025 503rd jacklynnepenick 812 117 21ms 13 Aug 2021 504th edsrzf 🇳🇿 811 75 37ms 22 Jul 2025 505th DialFrost 🇸🇬 811 112 400ms 8 Oct 2024 506th MeWhenI 🇻🇦 809 105 3ms 5 Jul 2024 507th sean-niemann 🇺🇸 809 141 206ms 31 Oct 2023 508th emgordon154 808 111 2,257ms 13 Dec 2024 509th GrayJoKing 🇦🇺 806 103 16ms 30 Oct 2023 509th Shanethegamer 🇺🇸 806 103 12ms 22 Apr 2025 511th lifthrasiir 🇰🇷 806 118 43ms 20 Nov 2024 511th CommandLeo 🇮🇹 806 118 225ms 22 Nov 2025 511th Lv0Sys 🇵🇱 806 118 19ms 20 Feb 2026 514th DialFrost 🇸🇬 805 100 475ms 19 Aug 2025 515th DialFrost 🇸🇬 804 98 34ms 28 Jul 2024 516th MeWhenI 🇻🇦 804 113 405ms 15 Nov 2022 516th sean-niemann 🇺🇸 804 113 387ms 8 Oct 2024 518th typeswitch-dev 🇵🇹 804 126 7ms 6 Jul 2024 519th KatieLG 🇬🇧 803 98 513ms 8 Oct 2025 520th edsrzf 🇳🇿 802 120 130ms 22 Dec 2025 521st Irratix 🇳🇱 801 95 14ms 22 Mar 2022 521st KatieLG 🇬🇧 801 95 18ms 16 Nov 2023 523rd DialFrost 🇸🇬 801 106 3ms 12 Feb 2024 524th stefangimmillaro 801 128 708ms 6 Oct 2025 525th MeWhenI 🇻🇦 800 152 43ms 17 May 2023 526th lynn 799 47 6ms 10 Jan 2022 527th bzijlema 🇳🇱 799 119 21ms 3 Jul 2024 528th DialFrost 🇸🇬 798 129 61ms 5 Jun 2024 529th Shanethegamer 🇺🇸 797 114 374ms 30 Oct 2023 530th sean-niemann 🇺🇸 797 126 44ms 5 May 2023 531st MeWhenI 🇻🇦 796 45 100ms 28 Jul 2022 532nd FlorianCassayre 🇫🇷 795 44 207ms 26 May 2024 533rd Yewzir 🇧🇪 795 129 619ms 24 Sep 2025 534th scpchicken 🇵🇼 794 78 173ms 4 May 2022 535th rucin93 🇵🇱 793 118 32ms 7 Dec 2025 536th MeWhenI 🇻🇦 792 118 503ms 4 Mar 2022 537th vezzick 792 120 21ms 5 Mar 2021 538th MeWhenI 🇻🇦 788 100 17ms 28 May 2023 539th ZakkkkAttackkkk 🇵🇭 786 121 21ms 26 Aug 2023 540th Shanethegamer 🇺🇸 784 74 6ms 6 Jan 2022 541st wiz0u 782 103 483ms 18 Aug 2025 542nd janbehrens 🇩🇪 779 78 1,122ms 3 Dec 2023 543rd SirBogman 🇺🇸 779 101 597ms 20 Jan 2024 544th OllieBoyne 🇬🇧 779 122 21ms 3 Jun 2021 544th Emutis 🇱🇹 779 122 19ms 17 Sep 2025 546th Steffan153 🇫🇮 778 103 31ms 14 Feb 2024 547th MeWhenI 🇻🇦 778 303 43ms 21 Apr 2025 548th CaedenHarper 🇨🇦 777 132 596ms 3 Oct 2025 549th m-tkach 🇺🇦 774 133 587ms 14 Aug 2023 549th michaelmoynihan 774 133 441ms 27 Aug 2025 551st primo-ppcg 🇹🇭 773 107 209ms 12 Feb 2022 552nd DialFrost 🇸🇬 773 121 9ms 7 Nov 2023 553rd rowechenzhong 773 123 21ms 25 Mar 2020 553rd giacomogallina 773 123 21ms 21 May 2020 553rd MichalMarsalek 🇨🇿 773 123 23ms 9 Oct 2022 553rd qpwoeirut 773 123 22ms 20 Nov 2025 553rd zhaohm14 773 123 19ms 9 Jan 2026 558th Yewzir 🇧🇪 773 139 5ms 9 Jun 2024 559th namelessiw 771 133 622ms 8 Oct 2025 560th Shanethegamer 🇺🇸 769 79 648ms 31 Oct 2023 First Prev 481–560 of 1,514 Next Last