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 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 721st efgen 611 120 12ms 28 Dec 2023 722nd jared-hughes 611 123 17ms 8 Sep 2022 722nd quimey 611 123 15ms 4 Jul 2023 722nd htareque 611 123 11ms 17 Oct 2023 725th wackbyte 611 306 266ms 7 Dec 2023 726th msbranicky 609 300 273ms 31 Aug 2023 727th scpchicken 🇵🇼 606 66 39ms 13 Feb 2022 728th andrewjc2000 606 124 19ms 14 Jan 2026 729th Shanethegamer 🇺🇸 604 232 2,852ms 16 Feb 2022 730th bizy-coder 603 110 428ms 16 Jan 2024 730th MeWhenI 🇻🇦 603 110 662ms 24 May 2024 730th CaedenHarper 🇨🇦 603 110 496ms 27 Dec 2024 733rd RockOfStone 603 163 2ms 14 Mar 2024 734th emgordon154 603 310 299ms 6 Mar 2025 735th bac0id 602 233 67ms 27 Jun 2024 736th RYNO8 601 125 16ms 16 Aug 2022 737th MeWhenI 🇻🇦 600 174 5ms 15 Oct 2023 738th emgordon154 600 414 1,448ms 4 Oct 2025 739th RobertHoeh 599 225 2,800ms 18 Dec 2025 740th janbehrens 🇩🇪 599 266 418ms 26 Feb 2022 740th cbrt-x 599 266 425ms 6 May 2022 742nd edsrzf 🇳🇿 597 67 38ms 14 Feb 2026 742nd denkyuu1 597 67 36ms 19 days ago 744th dzshn 596 126 15ms 15 Aug 2022 744th stefangimmillaro 596 126 14ms 10 Nov 2023 744th fgrosshans 🇫🇷 596 126 13ms 17 Jul 2024 744th NickTheEASDude 🇺🇸 596 126 21ms 21 Aug 2024 744th Pyroan 596 126 15ms 13 Mar 2025 744th 051 🇸🇬 596 126 47ms 8 Jan 2026 750th MaxElf999 592 127 16ms 10 Nov 2022 750th DrakeSeteraO 592 127 24ms 28 Oct 2025 752nd emgordon154 592 137 23ms 29 Jul 2025 753rd Shanethegamer 🇺🇸 591 134 93ms 4 Jun 2025 754th adoxography 588 68 39ms 20 Mar 2022 755th pschmid0 🇺🇸 588 142 5ms 17 Oct 2022 756th mwja 587 125 12ms 22 Aug 2024 757th fourth-bit 587 128 15ms 18 Nov 2022 757th Command-Master 587 128 96ms 29 Sep 2023 757th mathisfun271 587 128 36ms 13 Feb 2024 757th solisolu 587 128 20ms 30 Dec 2025 761st 0xjac 🇨🇭 586 312 298ms 8 Jun 2025 762nd Shanethegamer 🇺🇸 584 99 323ms 20 Apr 2022 763rd jared-hughes 584 103 44ms 18 Jul 2022 764th stefangimmillaro 584 190 118ms 22 Oct 2022 765th KatieLG 🇬🇧 584 231 194ms 21 Nov 2025 766th andre-lameirinhas 🇵🇹 583 129 16ms 29 Jul 2022 766th Mikey-Beep 🇬🇧 583 129 17ms 6 Oct 2022 766th cros107 🇦🇺 583 129 16ms 25 May 2024 766th cubed-guy 583 129 15ms 9 Jun 2024 766th wuduculfre 583 129 11ms 22 Jul 2025 766th retrohun 583 129 24ms 31 Dec 2025 772nd Kacarott 🇦🇺 582 114 834ms 4 Feb 2025 773rd eiburns 582 126 11ms 28 Feb 2022 773rd tomh1012 582 126 13ms 4 Mar 2022 773rd Vaekor 582 126 13ms 28 Jul 2023 773rd iczelia 🇩🇪 582 126 10ms 11 Oct 2025 777th Phil-RGOMEGA 581 169 2ms 30 Aug 2023 778th jared-hughes 579 69 41ms 10 Sep 2022 779th CedricGebistorf 578 130 17ms 16 Mar 2022 780th Mabeloid 🇳🇴 578 170 3ms 29 Sep 2024 781st Aurel300 🇨🇭 577 324 216ms 3 Jun 2024 782nd dokutan 576 101 129ms 20 Sep 2024 783rd MeWhenI 🇻🇦 576 234 467ms 19 Aug 2022 784th aliakseikalosha 576 238 417ms 16 Jul 2025 785th amollberg 🇸🇪 574 131 17ms 15 Feb 2022 785th BREMAUCY 🇫🇷 574 131 17ms 26 Jul 2023 785th vishwathg 574 131 16ms 25 Jul 2025 785th InigoK 🇺🇸 574 131 11ms 30 Aug 2025 785th Aquateraneal 🇺🇸 574 131 15ms 19 days ago 790th acollett89 573 128 11ms 4 Aug 2025 791st SirBogman 🇺🇸 572 116 508ms 16 Jan 2024 791st commandz0 🇺🇸 572 116 525ms 1 Sep 2025 793rd emgordon154 570 143 9ms 23 Dec 2024 794th mikehanus 569 132 16ms 21 Nov 2023 794th logvp 569 132 17ms 28 Dec 2023 796th arjanadriaanse 🇳🇱 568 50 5ms 23 Feb 2022 797th Indivicivet 565 133 17ms 9 May 2022 797th QuincyNash 🇺🇸 565 133 15ms 2 Dec 2022 797th joll05 🇸🇪 565 133 16ms 1 Oct 2025 800th aposteriorist 🇨🇦 562 240 473ms 28 Feb 2022 First Prev 721–800 of 1,185 Next Last