The Gray Code Decoder and Gray Code Encoder holes will go live in approximately 5 days. Why not try and solve them ahead of time?
τ 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 Yewzir 🇧🇪 582 246 305ms 3 Jan 2024 722nd snoozingnewt 🇨🇦 578 79 971ms 21 Nov 2025 723rd unfinishedprogram 578 103 11ms 21 Feb 2024 724th flawr 577 113 752ms 2 Jan 2019 725th dokutan 577 248 284ms 4 Jan 2024 726th KatieLG 🇬🇧 576 98 148ms 11 Dec 2022 726th cingulataluke 576 98 16ms 26 Aug 2023 728th dan-simon 575 67 267ms 29 Dec 2017 729th kmathis22 574 204 504ms 7 Dec 2025 730th Yewzir 🇧🇪 573 94 371ms 15 Jan 2024 731st boxjelly 573 175 3ms 7 Feb 2021 732nd MeWhenI 🇻🇦 573 230 448ms 15 Nov 2022 733rd 4hg 🇺🇸 572 47 60ms 22 Jul 2022 734th fisxoj 571 86 19ms 28 Apr 2018 735th janbehrens 🇩🇪 571 88 270ms 3 Dec 2023 736th MeWhenI 🇻🇦 570 61 12ms 15 Feb 2025 737th yokasuretsu 570 71 40ms 15 Apr 2018 737th Irratix 🇳🇱 570 71 49ms 27 Jun 2022 739th tomh1012 567 105 11ms 13 Oct 2020 739th Yax42 🇫🇷 567 105 12ms 5 Sep 2025 739th Lv0Sys 🇵🇱 567 105 17ms 20 Feb 2026 742nd dokutan 567 236 88ms 23 Jul 2025 743rd aksyristos 566 67 177ms 23 Jul 2023 744th MeWhenI 🇻🇦 566 149 53ms 12 Nov 2022 745th bac0id 565 100 17ms 26 Sep 2023 746th Shanethegamer 🇺🇸 565 110 1,245ms 2 Jun 2022 747th MeWhenI 🇻🇦 563 167 478ms 13 Oct 2023 748th leon-w 559 101 55ms 4 Jan 2019 749th CatsAreFluffy 557 107 17ms 19 Dec 2022 749th goodwyna21 557 107 15ms 27 Jan 2025 751st Yewzir 🇧🇪 555 261 5ms 19 Dec 2024 752nd Soyo-Wind 553 177 415ms 6 Nov 2025 753rd Shanethegamer 🇺🇸 551 70 176ms 2 Jun 2022 754th ShiraJoseph 🇺🇸 551 108 11ms 6 Feb 2023 755th KatieLG 🇬🇧 550 98 509ms 28 Oct 2024 756th dokutan 549 240 250ms 1 Jul 2025 757th MeWhenI 🇻🇦 548 144 788ms 21 Dec 2022 758th elgan65536 🇺🇸 545 254 120ms 7 Feb 2026 759th MeWhenI 🇻🇦 544 231 141ms 6 Aug 2023 760th albanian-laundromat 541 206 2ms 25 Jun 2025 761st dokutan 536 208 2ms 27 Mar 2024 762nd ndren 535 71 216ms 7 Dec 2025 763rd cure-honey 🇯🇵 535 259 145ms 7 Jul 2021 764th m-tkach 🇺🇦 534 209 2ms 26 Oct 2022 765th cros107 🇦🇺 533 106 1,614ms 5 Sep 2025 766th dcgjb 529 95 373ms 13 May 2024 767th jmerle 🇳🇱 528 107 16ms 6 Jul 2023 768th arrudagates 527 113 11ms 24 Jun 2021 769th MeWhenI 🇻🇦 525 264 161ms 12 Dec 2022 770th yokasuretsu 521 74 144ms 30 Jun 2018 771st marcin7Cd 521 128 24ms 21 Mar 2021 772nd NickTheEASDude 🇺🇸 518 109 836ms 20 Aug 2024 773rd Yewzir 🇧🇪 516 216 2ms 18 Jan 2024 774th jiaminglimjm 🇲🇾 514 110 15ms 27 Nov 2019 775th 2bular 513 113 1,692ms 17 Apr 2024 776th Ephellon 513 116 12ms 2 Dec 2022 777th neihousaigaai 509 111 2,572ms 7 May 2021 778th nwellnhof 🇩🇪 508 667 20ms 19 Nov 2022 779th dokutan 507 215 145ms 28 Mar 2024 780th MeWhenI 🇻🇦 507 220 51ms 26 Aug 2023 781st GalladeGuy 🇺🇸 506 198 5ms 25 May 2020 782nd Yewzir 🇧🇪 505 234 60ms 23 Dec 2023 783rd wh3n3v3r 🇨🇿 504 112 21ms 20 Nov 2024 784th inventshah 503 673 18ms 18 Nov 2022 785th dokutan 501 234 368ms 24 Sep 2025 786th inverseLorentz 🇦🇺 500 113 2,264ms 22 Feb 2024 786th cuboids 500 113 130ms 17 Jul 2024 788th dokutan 500 220 1ms 3 Apr 2024 789th commandz0 🇺🇸 499 108 529ms 1 Sep 2025 790th Herbert00709 🇵🇱 499 140 2,763ms 24 Oct 2024 791st cbrt-x 499 235 458ms 14 Oct 2021 792nd Natanaelel 🇸🇪 498 54 46ms 25 Jul 2022 793rd aksyristos 497 236 480ms 17 Feb 2023 794th JunkIce 496 114 14ms 24 Nov 2024 795th galloj 🇨🇿 494 685 89ms 1 Mar 2023 796th fgrosshans 🇫🇷 491 115 13ms 8 May 2023 797th KatieLG 🇬🇧 490 200 461ms 27 Oct 2022 798th dokutan 490 241 463ms 20 Aug 2024 799th janbehrens 🇩🇪 488 240 454ms 25 Apr 2023 800th frobinsonj 484 123 36ms 6 Dec 2019 First Prev 721–800 of 2,351 Next Last