The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 4 days. Why not try and solve them ahead of time?
Leap Years in Rust 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 1st acotis 1,000 56 119ms 24 Sep 2025 1st kumavale 1,000 56 130ms 27 Sep 2025 3rd andersk 🇺🇸 933 60 138ms 20 Mar 2020 3rd primo-ppcg 🇹🇭 933 60 114ms 2 May 2020 3rd JayXon 🇺🇸 933 60 124ms 23 Aug 2021 3rd Lydxn 🇨🇦 933 60 114ms 24 Aug 2021 3rd lynn 933 60 119ms 10 Sep 2021 3rd Super-Pizza 🇨🇦 933 60 141ms 22 May 2023 3rd Steffan153 🇫🇮 933 60 131ms 4 days ago 10th nipzu 889 63 118ms 20 Oct 2021 10th GrayJoKing 🇦🇺 889 63 123ms 9 Feb 2022 10th sean-niemann 🇺🇸 889 63 122ms 12 Apr 2022 10th MeWhenI 🇻🇦 889 63 122ms 10 Oct 2022 10th ovs-code 🇩🇪 889 63 138ms 21 Jun 2023 10th Seek64 🇩🇪 889 63 126ms 19 Oct 2023 10th DialFrost 🇸🇬 889 63 124ms 14 Nov 2023 10th dokutan 889 63 116ms 25 Sep 2024 10th nullie 889 63 129ms 30 Dec 2024 19th WhoisDavid 862 65 124ms 16 Sep 2020 19th argusdusty 🇺🇸 862 65 123ms 26 Dec 2020 19th janbehrens 🇩🇪 862 65 125ms 22 May 2021 19th mad4j 🇮🇹 862 65 115ms 4 Jul 2021 19th voytxt 🇨🇿 862 65 127ms 16 May 2022 19th stefangimmillaro 862 65 124ms 9 Jun 2023 19th r-brinke 🇳🇱 862 65 122ms 27 Dec 2023 19th 77Tigers 862 65 122ms 11 Apr 2024 19th mousetail 🇳🇱 862 65 126ms 8 Nov 2024 19th ian-h-chamberlain 🇺🇸 862 65 124ms 4 Nov 2025 19th luuumine 🇫🇷 862 65 127ms 16 Nov 2025 30th Serentty 848 66 116ms 31 May 2020 30th okaponta 848 66 114ms 11 Jan 2024 32nd dbdr 836 67 137ms 5 Jan 2020 32nd btjones0 836 67 127ms 27 Dec 2020 32nd verticallity 836 67 132ms 6 Apr 2022 32nd msbranicky 836 67 115ms 6 Oct 2023 32nd elgan65536 🇺🇸 836 67 122ms 9 Nov 2023 32nd klixel 🇨🇦 836 67 115ms 17 Nov 2023 32nd drabart 🇵🇱 836 67 121ms 16 Dec 2023 32nd Aurel300 🇨🇭 836 67 119ms 6 Jun 2024 32nd emgordon154 836 67 124ms 18 Feb 2025 41st yzhs 🇩🇪 824 68 125ms 15 Feb 2020 41st GinjaNinja32 824 68 125ms 16 Apr 2020 41st jiaminglimjm 🇲🇾 824 68 119ms 4 Jan 2021 41st dteague3989 824 68 120ms 26 May 2023 41st fantaize 824 68 126ms 16 days ago 46th b10011 🇫🇮 812 69 119ms 14 Feb 2021 46th Pena86 812 69 115ms 27 May 2021 46th p-vf 🇨🇭 812 69 119ms 25 Oct 2021 46th JGDoerrer 812 69 125ms 15 Feb 2022 46th kgodara 812 69 119ms 2 Mar 2023 51st wuzekai518 800 70 126ms 16 Jul 2024 51st unfinishedprogram 800 70 133ms 27 Jun 2025 51st Mabeloid 🇳🇴 800 70 123ms 31 Oct 2025 54th august-soderberg 789 71 121ms 19 May 2023 55th Shanethegamer 🇺🇸 778 72 131ms 13 Jan 2022 55th annaproxy 778 72 119ms 14 Feb 2022 57th timvermeulen 767 73 124ms 4 Jan 2020 58th Re-Adventures 🇮🇳 757 74 120ms 27 Aug 2022 58th mintyproof 757 74 118ms 7 Sep 2022 58th Creative0708 🇨🇦 757 74 130ms 16 Dec 2023 58th ludwigschlame 🇩🇪 757 74 123ms 24 Sep 2024 58th pogwolfe 757 74 139ms 2 Jun 2025 58th jaxmattfair 🇺🇸 757 74 123ms 2 Jun 2025 64th frozolotl 747 75 122ms 8 Jan 2020 64th connorslade 747 75 135ms 13 May 2022 64th Z-snails 747 75 121ms 27 Feb 2023 64th HumanoidCPU 747 75 122ms 19 Feb 2024 64th albanian-laundromat 747 75 186ms 23 Mar 2025 64th snoozingnewt 🇨🇦 747 75 128ms 29 Sep 2025 64th AndreiDTU 747 75 133ms 21 days ago 71st d0x2f 737 76 122ms 4 Jan 2020 71st scpchicken 🇵🇼 737 76 119ms 19 May 2022 71st StronkCheese 🇺🇸 737 76 126ms 20 Mar 2023 71st logancammish 737 76 122ms 21 Mar 2023 71st roguh 🇬🇹 737 76 128ms 14 Jan 2024 71st neel11235813 737 76 127ms 16 Mar 2024 71st elituf 737 76 125ms 4 Jan 2025 71st Pale-Vessel 737 76 125ms 23 Sep 2025 79th StHagel 727 77 137ms 13 Jul 2023 79th deerawj 727 77 134ms 7 Apr 2024 1–80 of 120 Next Last