Posts concerning Sudoku in general

New Printable Options for Daily Puzzles!

New today!  Our Puzzle pages now have a new pair of icons available – these take you directly to a full-sized version of the puzzle ready for printing to play offline!

The  Print icon will give you the puzzle with a blank grid, and the Pencil icon will give you the page with all of the sensible pencilmarks already filled in.

If you want absolutely all of the pencilmarks (sensible or not!) for the empty cells, so you can enjoy crossing them all out yourself, then change the “pencil=1” part of the web address to “pencil=2” which will do the trick!

Free sudoku for your local publications!

Are you in the need of a free Sudoku puzzle to add some extra interest to your newsletter or leaflet ?

It’s amazing how having a puzzle available means that it gets a bit of extra interest, and gives your regular readers an extra little reason to look forward to your next delivery!

We’ve just updated our Sudoku Bulletin Edition page with new links to puzzles – these are changed every month and are available in lovely big print sizes (high DPI) so that you can embed them into your document and they will scale and print without any loss of quality. There are also the full solutions to print too – either on another page in the same newsletter or in the next issue.


Play the latest Sudoku Of The Day puzzles directly in your browser!

By popular request (people have been asking us for it since we started the site!), I’ve been working on a playable Sudoku that works right in your browser!

It’s really a beta, in that it doesn’t look quite as polished as I would like it to become, and I haven’t decided on the final features that will be added, but all of the basic playable features – entering values, pencil marks, (and an undo!) are all in there now.

You can play any of the Sudoku Of The Day Daily Puzzles,  select the puzzle you’d like to play and tap on it, and then choose the option that says “Play this puzzle in your browser now!”

It runs directly in your browser and does not require any additional software to install! (No flash, no plugins, no extra programs!)

Please try it out and comment with your thoughts – did you play it? Did you complete the puzzle? Did it work right? Was it obvious how to use, or confusing?  Feel free to comment here or on the Play Sudoku Beta page itself !

The more useful feedback we get, the better the changes we can make to make it more playable and useful for everyone!

Speedier Site – faster downloads!

We’ve been working behind the scenes to improve how the pictures work here!

Some of the pages on the site (for instance the technique pages) have multiple Sudoku images showing, as they explain how to apply a technique. Some pages (for instance one of the Step-By-Step guides for one of the daily puzzles) can have over a hundred images, showing in detail how to solve one of our daily sudoku puzzles.

Those images are fairly small – perhaps 10-15kb each, but when you have a hundred, that’s over a megabyte of data our server has to send out, and your computer has to receive and store, and that’s all a slow process, especially if you’re on shared WiFi!

So we’ve been trying out Canvas and Javascript to send the puzzle and layout information in a condensed form in the pages, which asks your browser to paint the picture itself, rather than downloading it.  Our experiments here are that it saves anywhere from 100kb to 1Mb per page, and even on a fast connection that’s anything up to 10 seconds of saving!  It helps our server keep cool and mellow in the summer, and it means you don’t chew through quite so much data from your allowance!

Another bonus is that because it uses the nice fonts and technology in your computer, it will render the puzzles more sharply and clearly than before – so it should be good for readability.

We’ve tried to make it fall-back gracefully if you’re using a much older browser, so it’ll go back to the old image method if it needs to. We’ve tried on a number of mobile devices too and it seems to help them a bit, but we can see we still have layout/css problems all over the place to fix!

We’ve tested that printing still works, so hopefully everyone should be able to keep doing things the way they prefer.

Please let us know if you come across any problems!


For the techies:

We use a wordpress shortcode in our page to query our database for the appropriate puzzle information. This returns a puzzle ‘string’ (a sequence of usually 81 characters, to make up the 9×9 cells, sometimes more if there are pencilmarks to include or things like background shades and arrows).  The PHP that processes the shortcode writes this out as a small piece of javascript in the page. As your browser renders the page, it runs the javascript, and expands it out into either a canvas, or if the browser can’t handle a canvas, includes the good old img src for the puzzle from our server the old way.

If it’s running a canvas, it then runs a function to draw in the grid, numbers, pencilmarks, shading, and everything else, directly onto that canvas. All in far less time than it takes to request the equivalent picture from our server!  As a result the server is processing a single page, as the browser creates all of the images directly, rather than a page resulting in 50-100 different requests. The reduced load on the server means that everyone gets pages more quickly when lots of people are accessing at once!

More than 99% of the visitors to our site are using a modern browser so should get all of the benefits!




Updates for easier navigation and better printing

David and I have been working on improving some of the functionality of the site – it’s now possible to navigate more easily to the daily puzzle archive pages, and select the puzzle you want to play;  You can then print just that puzzle, without having the solution right in front of you!

From there you can take a look at the solution too (a side-by-side view in case you do want to print both), or to go straight to the step-by-step guide to solving the puzzle.

We’ve added in by request the rating value for each puzzle, and also the calculated techniques that will get you to the solution – of course you’re free to use whatever techniques work for you!

Finally we’re working on making many more of the pages (particularly the daily page, and individual puzzles) much more printer friendly by removing sections that you don’t need on paper. Hug that tree!

In the future we’re hoping to have a feature on the site where you can play right in the browser too – and still have access to all the solver assistance, pencilmarks, and help from the mobile app – but that’s likely some time away!

If you have any more suggestions for the site – or if you’ve found a page that is broken, please get in touch – we do our best to make the site work as well as possible for everyone, as well as being welcoming for new users!