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?
Collatz 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 875th mhgockel 846 63 11ms 19 Aug 2023 875th NickTheEASDude 🇺🇸 846 63 11ms 18 Jan 2024 875th 823126 846 63 13ms 14 Nov 2024 875th Palladium02 846 63 12ms 12 May 2025 875th 4very 846 63 12ms 10 Jun 2025 875th Ultra814 846 63 13ms 21 Aug 2025 887th NewDefectus 🇮🇱 846 73 3ms 6 May 2022 887th inventshah 846 73 2ms 12 Jun 2022 887th Natanaelel 🇸🇪 846 73 2ms 15 Jun 2022 887th Herbert00709 🇵🇱 846 73 2ms 22 Dec 2023 887th LorenzoDeGaspari 846 73 2ms 27 May 2024 887th Bpc-CPU 846 73 2ms 12 Jul 2025 887th AZTECCO 846 73 2ms 16 Sep 2025 887th CaedenHarper 🇨🇦 846 73 2ms 28 Sep 2025 887th prestosilver 🇺🇸 846 73 2ms 3 Dec 2025 887th albanian-laundromat 846 73 3ms 20 Jan 2026 887th madex 🇩🇪 846 73 2ms 8 days ago 898th Shanethegamer 🇺🇸 846 98 126ms 26 Oct 2022 898th emgordon154 846 98 125ms 18 Feb 2025 900th retrohun 845 64 4ms 6 Nov 2022 900th Re-Adventures 🇮🇳 845 64 4ms 7 Nov 2022 900th stellartux 845 64 4ms 26 Dec 2023 900th bac0id 845 64 4ms 29 Jun 2024 900th snoozingnewt 🇨🇦 845 64 4ms 1 Sep 2024 900th albanian-laundromat 845 64 4ms 22 Sep 2025 906th janAkali 🇷🇺 844 77 131ms 12 Feb 2025 907th bschorno 844 92 341ms 12 Oct 2022 907th ChrisTheisen 844 92 345ms 14 Dec 2022 907th kellantech 844 92 351ms 4 Jul 2023 907th Mezzofloat 844 92 358ms 26 Aug 2023 907th Maximizer02 844 92 365ms 1 Oct 2023 907th madeforlosers 844 92 380ms 21 Nov 2024 907th ChromaChroma 844 92 403ms 7 Oct 2025 907th snoozingnewt 🇨🇦 844 92 398ms 8 Oct 2025 915th DialFrost 🇸🇬 843 66 87ms 7 Apr 2025 915th KasperKivimaeki 🇫🇮 843 66 7ms 22 Dec 2025 917th krcs 🇵🇱 842 53 284ms 9 May 2022 917th ryanlanegit 842 53 311ms 19 Jun 2022 917th sisyphus-ppcg 🇦🇺 842 53 456ms 15 Aug 2022 920th MeWhenI 🇻🇦 842 71 110ms 13 Dec 2022 921st SirBogman 🇺🇸 842 89 38ms 4 May 2022 922nd error256 841 81 68ms 13 Sep 2024 923rd CLOStrophobic 🇮🇹 841 89 42ms 14 Feb 2025 924th kmathis22 841 100 31ms 13 Nov 2025 925th emplv 🇱🇻 841 124 25ms 31 Oct 2022 926th raszpi 🇭🇺 840 77 111ms 1 Sep 2023 927th MeWhenI 🇻🇦 840 164 1,639ms 7 Nov 2025 928th frankgraziano 839 66 4ms 20 Apr 2025 929th eshilo-draper 839 75 89ms 6 Sep 2022 929th kmathis22 839 75 91ms 5 Sep 2025 931st sean-niemann 🇺🇸 839 76 141ms 8 Oct 2024 932nd beardotpdf 839 99 422ms 12 Dec 2025 933rd Codsilla 🇨🇦 838 51 263ms 1 Jul 2022 934th DialFrost 🇸🇬 838 56 1,180ms 1 Sep 2025 934th GolfingSuccess 🇬🇷 838 56 905ms 17 Feb 2026 936th steffan-polygolf 838 81 10ms 23 Feb 2023 936th FranklinJiaChen 838 81 9ms 23 Feb 2026 938th Andriamanitra 🇫🇮 838 83 12ms 17 Apr 2023 938th Natanaelel 🇸🇪 838 83 12ms 8 Jul 2023 940th Steffan153 🇫🇮 838 97 31ms 18 Jan 2023 941st CatsAreFluffy 838 101 61ms 18 Feb 2023 941st annaproxy 838 101 55ms 9 May 2023 941st wojtekmal 838 101 57ms 15 Nov 2023 941st HumanoidCPU 838 101 57ms 6 May 2024 941st eMGeeneer 838 101 435ms 27 Jun 2024 941st bac0id 838 101 69ms 29 Jun 2024 941st michaelmoynihan 838 101 435ms 3 Sep 2025 941st snoozingnewt 🇨🇦 838 101 467ms 6 Oct 2025 949th DialFrost 🇸🇬 837 83 17ms 1 Jan 2026 950th dokutan 837 88 39ms 9 Jun 2024 951st scpchicken 🇵🇼 836 55 11ms 4 May 2022 951st SirBogman 🇺🇸 836 55 8ms 5 May 2022 951st Shanethegamer 🇺🇸 836 55 6ms 19 May 2023 951st DialFrost 🇸🇬 836 55 11ms 14 Feb 2025 955th GolfingSuccess 🇬🇷 836 109 17ms 9 days ago 956th SirBogman 🇺🇸 835 36 9ms 5 May 2022 956th Natanaelel 🇸🇪 835 36 87ms 15 Jun 2022 956th Steffan153 🇫🇮 835 36 91ms 18 Jan 2023 956th codereport 🇨🇦 835 36 9ms 1 Jun 2024 956th GolfinK 835 36 8ms 21 Nov 2024 First Prev 881–960 of 3,621 Next Last