The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 6 days. Why not try and solve them ahead of time?
Reverse Polish Notation 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 641st annaproxy 729 141 22ms 14 Dec 2022 642nd HPWiz 🇳🇿 728 39 5ms 23 Nov 2023 643rd ChiefChippy2 727 101 11ms 12 Feb 2022 643rd Frowny 727 101 33ms 16 Feb 2022 643rd fitzdotlol 🇺🇸 727 101 11ms 8 Mar 2022 643rd neel11235813 727 101 12ms 17 Mar 2024 643rd madex 🇩🇪 727 101 11ms 9 Jul 2024 643rd wh3n3v3r 🇨🇿 727 101 11ms 8 Nov 2024 649th syntax-rules 726 193 420ms 25 Dec 2022 650th SniperSmiley 🇺🇸 725 143 17ms 8 Jul 2022 650th Europe2048 725 143 23ms 22 Oct 2024 650th moustave 725 143 11ms 7 Apr 2025 653rd Yax42 🇫🇷 725 189 412ms 21 Jan 2026 654th Shanethegamer 🇺🇸 725 220 367ms 24 Sep 2025 654th sean-niemann 🇺🇸 725 220 362ms 24 Sep 2025 656th Kacarott 🇦🇺 723 114 834ms 4 Feb 2025 657th GolfingSuccess 🇬🇷 723 194 441ms 14 Feb 2022 658th Shanethegamer 🇺🇸 721 190 371ms 9 Apr 2025 659th adoxography 720 68 39ms 20 Mar 2022 660th randolchance 720 144 17ms 4 Jan 2024 660th roupiq 🇵🇱 720 144 17ms 1 Mar 2024 660th Deppyforce 720 144 17ms 9 Nov 2025 663rd GolfingSuccess 🇬🇷 720 163 2ms 5 Dec 2022 664th inventshah 719 102 15ms 13 Feb 2022 664th smclaughlin-cf 719 102 12ms 4 Mar 2025 666th MeWhenI 🇻🇦 718 166 208ms 17 Nov 2022 667th emgordon154 717 115 430ms 11 Aug 2025 668th Frowny 716 185 145ms 18 Mar 2022 669th Shanethegamer 🇺🇸 716 261 244ms 30 Apr 2022 670th LeeCamp 715 145 16ms 14 Feb 2022 670th hellwue 715 145 11ms 7 Feb 2023 670th adamnielson42 🇺🇸 715 145 23ms 8 Oct 2024 670th Mabeloid 🇳🇴 715 145 26ms 4 May 2025 670th te-chnical 715 145 16ms 9 Jul 2025 675th Alex-x90 🇺🇸 715 196 446ms 24 Oct 2025 676th emgordon154 714 137 12ms 26 Sep 2024 677th stefangimmillaro 714 192 458ms 10 Oct 2023 678th stefangimmillaro 714 256 41ms 3 Jan 2023 679th JGDoerrer 713 262 206ms 29 Jun 2022 680th daniel-pedersen 🇸🇪 712 103 11ms 6 Mar 2022 680th Heathcorp 🇦🇺 712 103 14ms 27 Apr 2022 680th snoozingnewt 🇨🇦 712 103 12ms 23 Sep 2023 680th FortuiteMan 🇫🇷 712 103 11ms 10 Oct 2024 680th SiBeepBoop 712 103 11ms 15 Apr 2025 680th alexsave 712 103 10ms 27 Dec 2025 686th prplz 🇦🇺 712 165 2ms 14 Feb 2022 686th Szum123321 🇵🇱 712 165 2ms 29 Nov 2023 686th JohandeRuiter 🇳🇱 712 165 2ms 11 Feb 2025 689th albanian-laundromat 712 349 1,412ms 6 Nov 2025 690th kg583 🇺🇸 711 145 5ms 9 Jun 2025 691st KatieLG 🇬🇧 710 69 40ms 12 Feb 2022 691st jared-hughes 710 69 41ms 10 Sep 2022 693rd SirBogman 🇺🇸 710 116 508ms 16 Jan 2024 693rd commandz0 🇺🇸 710 116 525ms 1 Sep 2025 695th karhuthebear 710 146 17ms 6 May 2022 695th Bonjour27891 🇻🇳 710 146 10ms 17 Jul 2022 697th weeble 709 138 4ms 18 Aug 2024 698th CaedenHarper 🇨🇦 709 225 366ms 3 days ago 699th Natanaelel 🇸🇪 708 45 65ms 26 Sep 2023 700th janbehrens 🇩🇪 706 104 15ms 14 Apr 2023 700th m-tkach 🇺🇦 706 104 11ms 3 Jan 2025 702nd MeWhenI 🇻🇦 706 204 2ms 11 Sep 2022 703rd CaedenHarper 🇨🇦 706 259 346ms 20 Nov 2025 704th SomeKitten 🇺🇸 705 147 26ms 29 Aug 2022 704th Bodo171 705 147 19ms 7 Dec 2022 704th vgamula 🇺🇦 705 147 18ms 6 Nov 2023 704th croc54 705 147 17ms 27 Jan 2025 708th edsrzf 🇳🇿 705 184 1,294ms 29 Apr 2025 709th AlephSquirrel 704 37 4ms 3 Aug 2023 710th duckyluuk 🇳🇱 704 117 465ms 26 Mar 2024 711th Alex-x90 🇺🇸 703 167 1ms 8 Feb 2023 712th davecame 700 148 29ms 18 Sep 2023 712th jatloe 700 148 16ms 6 Sep 2024 714th vgamula 🇺🇦 700 226 32ms 6 Nov 2023 715th Mandrzejy 🇵🇱 699 168 2ms 3 Nov 2024 716th stefangimmillaro 698 193 3,008ms 12 Nov 2024 717th stefangimmillaro 698 262 301ms 5 May 2025 717th edsrzf 🇳🇿 698 262 300ms 10 Jun 2025 719th primo-ppcg 🇹🇭 696 48 1,032ms 15 Feb 2022 720th emgordon154 694 118 1,301ms 3 Dec 2024 First Prev 641–720 of 1,191 Next Last