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?
Reverse Polish Notation 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 153rd xsot 🇸🇬 846 48 8ms 6 Jul 2025 153rd Solathian 846 48 6ms 3 days ago 163rd TFeld00 🇩🇰 844 89 100ms 22 Apr 2022 164th Steffan153 🇫🇮 844 96 356ms 11 Jul 2024 164th edsrzf 🇳🇿 844 96 8ms 16 Aug 2025 166th JayXon 🇺🇸 843 69 131ms 17 Aug 2024 167th akshatj27 🇦🇶 843 87 11ms 12 Feb 2022 167th itsh01 843 87 12ms 15 Feb 2022 167th subzey 843 87 14ms 18 Feb 2022 167th emgordon154 843 87 14ms 7 Aug 2024 167th ovs-code 🇩🇪 843 87 12ms 16 Nov 2024 167th lukegustafson 🇺🇸 843 87 11ms 24 days ago 173rd IanUtley 843 122 16ms 28 Jan 2024 174th nwellnhof 🇩🇪 842 50 1,237ms 15 Feb 2022 175th xsot 🇸🇬 842 73 20ms 6 Jul 2025 176th GrayJoKing 🇦🇺 842 152 1,417ms 24 Jul 2025 177th pardouin 🇫🇷 842 160 2,702ms 14 Nov 2024 178th emplv 🇱🇻 842 217 301ms 19 Feb 2022 179th Lydxn 🇨🇦 841 31 4ms 28 Jul 2023 179th GrayJoKing 🇦🇺 841 31 4ms 3 Aug 2023 181st namelessiw 841 163 436ms 1 Aug 2025 182nd m-tkach 🇺🇦 841 188 32ms 9 Feb 2026 183rd b-illy 🇬🇧 840 79 423ms 7 Sep 2024 183rd sean-niemann 🇺🇸 840 79 485ms 6 Jun 2025 183rd fuzzylojik-golf 🇺🇸 840 79 662ms 8 Sep 2025 183rd kg583 🇺🇸 840 79 699ms 31 Dec 2025 187th MarcMush 🇫🇷 840 80 675ms 13 Jan 2024 188th nwellnhof 🇩🇪 840 167 430ms 16 Feb 2022 188th MostParsingVex 840 167 62ms 3 Jan 2025 190th edsrzf 🇳🇿 839 123 6ms 11 Aug 2025 191st bitsandbeyond 🇳🇱 838 69 386ms 9 Oct 2025 192nd xsot 🇸🇬 838 75 2ms 23 Feb 2026 193rd JayXon 🇺🇸 838 139 2ms 21 Feb 2022 194th CLOStrophobic 🇮🇹 838 158 153ms 26 May 2025 195th edsrzf 🇳🇿 838 223 239ms 10 Jun 2025 196th JayXon 🇺🇸 837 161 467ms 14 Jul 2023 197th HPWiz 🇳🇿 835 40 1,032ms 10 Jan 2026 198th dvargas46 🇺🇸 835 72 53ms 21 Dec 2022 199th jakobkordez 🇸🇮 835 90 38ms 1 Nov 2022 200th stefangimmillaro 835 98 1,285ms 10 Dec 2024 201st MeWhenI 🇻🇦 835 164 461ms 19 Jun 2025 202nd Argeento 🇵🇱 834 88 12ms 13 Feb 2022 202nd coreynash 834 88 11ms 15 Feb 2024 202nd thisishowmymindworks 🇳🇴 834 88 11ms 24 Jun 2024 205th Bubbler-4 833 69 34ms 21 Feb 2022 205th ovs-code 🇩🇪 833 69 34ms 1 Mar 2025 207th btnlq 833 160 6ms 24 Sep 2022 208th Shanethegamer 🇺🇸 832 190 33ms 10 Feb 2026 208th Steffan153 🇫🇮 832 190 32ms 23 days ago 210th Steffan153 🇫🇮 831 70 140ms 6 Aug 2024 210th sean-niemann 🇺🇸 831 70 128ms 11 Aug 2024 212th Steffan153 🇫🇮 831 74 21ms 7 Feb 2023 212th GrayJoKing 🇦🇺 831 74 20ms 12 Feb 2023 214th emgordon154 831 162 2,728ms 30 Jan 2025 215th snoozingnewt 🇨🇦 830 80 383ms 5 Dec 2025 216th acotis 830 225 241ms 10 Feb 2026 217th Natanaelel 🇸🇪 829 49 7ms 10 Feb 2026 218th GrayJoKing 🇦🇺 829 118 8ms 21 Aug 2024 219th btnlq 827 76 2ms 7 Nov 2022 220th Steffan153 🇫🇮 827 99 1,283ms 4 May 2023 221st Z-snails 827 160 141ms 28 Feb 2023 221st Jeremy-Stafford 827 160 146ms 28 Feb 2023 223rd Steffan153 🇫🇮 826 77 1,779ms 17 Feb 2026 224th ndren 826 91 34ms 11 Nov 2023 224th dokutan 826 91 15ms 14 Sep 2024 224th 5quiwyrm 826 91 16ms 12 Nov 2024 227th sisyphus-ppcg 🇦🇺 826 101 5ms 14 Feb 2022 228th jkelly467 826 163 2,973ms 1 Dec 2025 229th primo-ppcg 🇹🇭 825 125 6ms 31 Jan 2023 230th snyderek 🇺🇸 825 170 62ms 1 Dec 2024 231st saito-ta 🇯🇵 824 73 256ms 25 Jan 2023 232nd ScottHamper 824 89 14ms 18 Feb 2022 232nd Shanethegamer 🇺🇸 824 89 12ms 4 May 2023 232nd kirjavascript 824 89 11ms 14 Feb 2025 235th sean-niemann 🇺🇸 824 99 127ms 14 Sep 2023 235th edsrzf 🇳🇿 824 99 7ms 17 Jan 2025 237th sean-niemann 🇺🇸 822 127 3ms 8 Jan 2025 237th Steffan153 🇫🇮 822 127 2ms 13 Feb 2026 239th Steffan153 🇫🇮 822 135 108ms 4 May 2023 240th strout 822 161 149ms 15 Dec 2023 First Prev 161–240 of 1,185 Next Last