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?
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 481st retrohun 742 81 11ms 15 Dec 2023 482nd DialFrost 🇸🇬 742 110 89ms 21 Jun 2025 483rd DialFrost 🇸🇬 741 99 11ms 24 Dec 2024 483rd JOrE20 741 99 11ms 7 Jan 2026 485th luuumine 🇫🇷 741 252 200ms 28 Nov 2025 486th primo-ppcg 🇹🇭 740 54 39ms 14 Feb 2022 486th janlelis 740 54 68ms 21 Sep 2024 486th ovs-code 🇩🇪 740 54 38ms 27 Dec 2024 486th sean-niemann 🇺🇸 740 54 39ms 3 Aug 2025 486th Natanaelel 🇸🇪 740 54 41ms 10 Feb 2026 491st scpchicken 🇵🇼 739 57 1,297ms 13 Feb 2022 491st SirBogman 🇺🇸 739 57 1,890ms 23 Jan 2024 493rd tailorspy 738 190 69ms 1 Jun 2024 494th dokutan 737 90 425ms 14 Feb 2026 495th neel11235813 737 102 10ms 16 Jan 2023 496th AlephSquirrel 737 140 5ms 25 Jan 2025 497th hemphen 737 186 374ms 20 Oct 2022 498th Shanethegamer 🇺🇸 737 248 298ms 20 Apr 2022 499th zacjl 735 47 2ms 22 Jan 2025 499th GrayJoKing 🇦🇺 735 47 3ms 5 Jun 2025 501st chasewalden 734 100 11ms 24 Apr 2023 501st MeWhenI 🇻🇦 734 100 11ms 3 Aug 2024 501st Salutations45 734 100 14ms 12 Nov 2024 504th MeWhenI 🇻🇦 734 249 291ms 7 Jul 2023 505th DialFrost 🇸🇬 733 82 44ms 23 Apr 2025 506th clockworknazo 732 84 22ms 13 Oct 2022 506th ovs-code 🇩🇪 732 84 20ms 7 Feb 2023 506th edsrzf 🇳🇿 732 84 19ms 9 Nov 2025 509th inventshah 732 182 3ms 14 Sep 2022 510th edsrzf 🇳🇿 731 87 1,022ms 18 Feb 2026 511th edsrzf 🇳🇿 731 112 1,341ms 4 Feb 2026 512th DialFrost 🇸🇬 731 218 387ms 24 Sep 2025 513th DialFrost 🇸🇬 730 103 11ms 19 Dec 2022 514th nullie 730 256 203ms 11 Mar 2025 515th annaproxy 729 141 22ms 14 Dec 2022 516th HPWiz 🇳🇿 728 39 5ms 23 Nov 2023 517th Shanethegamer 🇺🇸 728 183 4ms 11 Sep 2022 518th ChiefChippy2 727 101 11ms 12 Feb 2022 518th Frowny 727 101 33ms 16 Feb 2022 518th fitzdotlol 🇺🇸 727 101 11ms 8 Mar 2022 518th neel11235813 727 101 12ms 17 Mar 2024 518th madex 🇩🇪 727 101 11ms 9 Jul 2024 518th wh3n3v3r 🇨🇿 727 101 11ms 8 Nov 2024 524th Natanaelel 🇸🇪 726 58 1,437ms 13 Feb 2022 525th syntax-rules 726 193 420ms 25 Dec 2022 526th Yax42 🇫🇷 725 189 412ms 21 Jan 2026 527th Shanethegamer 🇺🇸 725 220 367ms 24 Sep 2025 527th sean-niemann 🇺🇸 725 220 362ms 24 Sep 2025 529th GolfingSuccess 🇬🇷 724 184 2ms 11 Sep 2022 530th antimon2 🇯🇵 723 93 742ms 13 Feb 2022 531st GolfingSuccess 🇬🇷 723 194 441ms 14 Feb 2022 532nd ovs-code 🇩🇪 722 113 129ms 2 Jul 2025 533rd Shanethegamer 🇺🇸 721 190 371ms 9 Apr 2025 534th inventshah 719 102 15ms 13 Feb 2022 534th smclaughlin-cf 719 102 12ms 4 Mar 2025 536th Frowny 716 185 145ms 18 Mar 2022 537th Shanethegamer 🇺🇸 716 261 243ms 30 Apr 2022 538th GolfingSuccess 🇬🇷 715 163 2ms 5 Dec 2022 539th Alex-x90 🇺🇸 715 196 446ms 24 Oct 2025 540th JayXon 🇺🇸 714 56 40ms 23 Feb 2025 540th pardouin 🇫🇷 714 56 69ms 12 Sep 2025 542nd emgordon154 714 137 12ms 26 Sep 2024 543rd stefangimmillaro 714 192 458ms 10 Oct 2023 544th stefangimmillaro 714 256 41ms 3 Jan 2023 545th JGDoerrer 713 262 190ms 29 Jun 2022 546th daniel-pedersen 🇸🇪 712 103 11ms 6 Mar 2022 546th Heathcorp 🇦🇺 712 103 14ms 27 Apr 2022 546th FortuiteMan 🇫🇷 712 103 11ms 10 Oct 2024 546th SiBeepBoop 712 103 11ms 15 Apr 2025 546th alexsave 712 103 10ms 27 Dec 2025 551st Shanethegamer 🇺🇸 712 138 2ms 12 Feb 2022 552nd albanian-laundromat 712 349 1,420ms 6 Nov 2025 553rd kg583 🇺🇸 711 145 5ms 9 Jun 2025 554th JohandeRuiter 🇳🇱 710 164 2ms 11 Feb 2025 555th weeble 709 138 4ms 18 Aug 2024 556th CaedenHarper 🇨🇦 709 225 366ms 5 days ago 557th Natanaelel 🇸🇪 708 45 65ms 26 Sep 2023 558th janbehrens 🇩🇪 706 104 15ms 14 Apr 2023 558th m-tkach 🇺🇦 706 104 11ms 3 Jan 2025 558th dokutan 706 104 11ms 15 Jun 2025 First Prev 481–560 of 1,185 Next Last