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Feedback and Questions

I've received a lot of interesting comments and questions from Sudoku fans over the last few years and this page is where I try to answer them. I'm also directing Str8ts feedback here. Please feel free to drop me a note on the side of the page. Or you can email me directly at andrew@str8ts.com.

Post a Comment or Question here...

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Any Sudoku you want to publish here for easy loading into the solver - Either 81 numbers or the packed string version.

	public - comment/question will be added to feedback column
	private - email comment/question directly to Andrew Stuart, don't display here

Comment, question or feedback:

Please enter the
letters you see:

If you are writing to alert me of a problem (thank-you!) please include a url to the page in question.
Can get fixes in quicker if I know immediately where to go.

Many thanks to all the people who have helped improve the solvers and strategies with their feedback!

Wednesday 10-Sep-2025

... by: Handle, Water

Dead Mr. Straits,

unfortunately I'm too dumb to understand some of these great explanations of diabolical, extreme etc. strategies.

Would it be possible to make puzzles where you learn these strategies interactively and with a focussed way, e. g. you're presented with situations where the specific strategy applies and have to solve them yourself, step by step?

Thank you so much!
Bridge Troll

Andrew Stuart writes:

I'm sure you're not. And yes the more complex strategies are of interest to programmers really although some people have told me they pen and paper them. But you can find “exemplars” at the bottom of most documentation pages which are trivial apart from the strategy for that page. Also, pick moderately difficult puzzles and then try the three hint modes (next to “take step”). Use Take Step until an interesting point is reached. Three hint modes: you can be presented with the pattern – find the elimination, or the elimination – find the pattern; or just the strategy name – find the pattern AND the elimination.

Monday 8-Sep-2025

... by: H, Sweden

Why does the solver auto remove numbers repeated in the two diagonals?

Andrew Stuart writes:

What solver? Should only be on Sudoku X. Drop me an email address so I can reply directly.

Monday 25-Aug-2025

... by: David, Hong Kong

I like the new format but after building the cages I cannot figure out how to enter the clues. It was easy in the old version,

Andrew Stuart writes:

Click on the blue button "Step 2". I had to split the two tasks as the operations were too complicated for so many different devices.

Wednesday 20-Aug-2025

... by: DavidC, USA

Hello Andrew, the various examples that you provide often have two links: "Load Example", and "From the Start". It seems that "Load Example" is identical to "From the Start" and thus the state of the example (solved cells vs. clue cells, and candidates) isn't reproducible. I think the links were different in the recent past where "Load Example" would have a longer string starting with "S9B".

Andrew Stuart writes:

I do have a job to go through the examples and replace the old string with the new one so the example loads directly. Been “as and when” so far. They should be distinct however.

Thursday 14-Aug-2025

... by: Tony Payne, United Kingdom

Hi neighbour
Is it an intended "feature" of this website that I was asked to confirm my cookie choices twice? ;o)
First on https://www.sudokuwiki.org/
Second on https://www.str8ts.com/Daily_str8ts
Didn't happen when I went back into the site

Andrew Stuart writes:

I think it's necessary now. I don’t have cross-domain cookies and the browsers don't like it when I try, so that’s where we are I'm afraid. Different sites, click again

Monday 11-Aug-2025

... by: Mark, WV

Re: 6x6 KenDoku Solver- Sample 38

Grader gives "Empty cell: E6"
Due to that the Solve Path ends up broken.
Going step by step, when it comes to E6, it takes out all numbers in D6 resulting in a "0" for the cell solution.

Andrew Stuart writes:

Thanks for the report Mark
Simplest is to delete that sample puzzle which I've now done
Refresh

Saturday 9-Aug-2025

... by: Bob, Russia

The solver page (/sudoku.aspx) is behaving in a very strange way being open on Samsung Internet browser (Galaxy S22+). Many buttons don't work at all (such as Email to a friend, Solve path etc.). Disclaimer in a box under the playfield claims to update to version 2.35 <> 2.37, while this mobile browser has neither keyboard (for Ctrl+F5) nor an option to clear specific site cashes. Please add a UI button for site update action.

Andrew Stuart writes:

Hi Bob. Yes that script should not have been there. I sometimes upload it to test but the real solver is sudoku.htm. I've deleted sudoku.aspx

Wednesday 6-Aug-2025

... by: Charp, Canada

Hi there. The st8ts main page hasn't been loading properly for me for a few days on my laptop in firefox.
https://www.str8ts.com/
Is the issue happening on your end or mine? Missing my daily asymmetrical st8ts!
Thanks

Andrew Stuart writes:

Seems okay to me. Is it persisting in not showing? Add an email address so I can reply directly.

Monday 21-Jul-2025

... by: Antonia Natale, Denver CO

Andrew: A friend of mine just showed me your Sudoku app and I really loved it. However, I have an iPad. Do you have a workaround for your app to run on Apple devices or plans to create an Apple compatible version?

Thanks!

Andrew Stuart writes:

I'm afraid I don't own a Mac and therefore can't run XCode and therefore can't create Apple Apps. The 5 Daily Puzzle app is going to get delisted soon for the same reason. Something I'd like to change , we'll have to see.

Saturday 19-Jul-2025

... by: JVic, Canada

Hello, https://www.sudokuwiki.org/Daily_Killer_Sudoku.aspx does not remember filled in entries after a refresh like it used to. Thanks.

Also, https://www.str8ts.com/Main_Page and https://www.str8ts.com/daily_str8ts should show the same puzzles, the Asymmetrical puzzle is sometimes missing from the second page.

Andrew Stuart writes:

Just checked and the entries are being saved and reloaded for me. Check your cookie caching? Daily Str8ts page hasn't had the second asymmetric puzzle for a long time. Just on the main page

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Thank-you everyone for all your questions and contributions.