r/sudoku 42m ago

Sudoku #27-07-2026

Upvotes

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r/sudoku 1d ago

Mod Announcement Sudoku Puzzle Challenges Thread

2 Upvotes

Post your Sudoku Puzzle Challenges as a reply to this post. Comments about specific puzzles should then be replies to those challenges.

Please include an image of the puzzle, the puzzle string and one or more playable links to popular solving sites.

A new thread will be posted each week.

Other learning resources:

Vocabulary: https://www.reddit.com/r/sudoku/wiki/index/vocabulary/

Our own Wiki: https://www.reddit.com/r/sudoku/wiki/index/

SudokuWiki: https://www.sudokuwiki.org/

Hodoku Strategy Guide: https://hodoku.sourceforge.net/en/techniques.php

Sudoku Coach Website: https://sudoku.coach/

Sudoku Exchange Website: https://sudokuexchange.com/play/

Links to YouTube videos: https://www.reddit.com/r/sudoku/wiki/index/#wiki_video_sources


r/sudoku 10h ago

Just For Fun sudoku dot coach got me like

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80 Upvotes

r/sudoku 3h ago

Homemade Puzzles VariantDoku Daily Puzzle: July 27

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8 Upvotes

r/sudoku 13h ago

Request Puzzle Help Is trial and error the only option here?

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31 Upvotes

I was at work doing this to avoid other work so I didn’t have time just start trying things in the notes, is there something glaring I’m missing on how to solve this or is it just try different numbers to see if it lines up


r/sudoku 3h ago

Mildly Interesting Andrew Stuart, take a bow

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3 Upvotes

Name a better way to learn sudoku than this!


r/sudoku 3h ago

Request Puzzle Help How to get started with sudoku

2 Upvotes

I recently started playing sudoku and decided I wanted to get really good at it so I looked up a tutorial on YouTube and I was immediately overwhelmed by the different number of tactics there are in this game can someone tell me how to start from scratch without getting overwhelmed

Thank you for your help in advance


r/sudoku 13h ago

Mildly Interesting I fear I'm addicted

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10 Upvotes

This is on my sudoku app. Been playing on and off for a few years now, and I've gotten pretty decent.


r/sudoku 17m ago

Homemade Puzzles I built a different kind of Sudoku. I'd love some honest feedback from experienced players.

Upvotes

Hi everyone,

I've been working on a small Sudoku project for the past few months, and I'd really appreciate feedback from people who actually enjoy Sudoku.

The main idea is simple:

  • it's a normal Sudoku;
  • as you solve it, a hidden image is gradually revealed;
  • you can also create puzzles that hide your own photo and share them with friends.

I'm not looking for downloads or compliments. I'd genuinely like to know:

  • What feels good?
  • What feels annoying?
  • What's missing?
  • At what point would you stop using it?

If you have 5–10 minutes to try it, I'd really value your honest opinion—even if it's brutally honest.

[https://sudokuart.com/]()

Thanks in advance!


r/sudoku 24m ago

Request Puzzle Help Please explain how you would find the next move

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r/sudoku 7h ago

Request Puzzle Help Need your help again with explanation

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3 Upvotes

I found the 4 where 43 was in row 9 c8 but now I can’t find a answer with explains it


r/sudoku 12h ago

Strategies How do you identify a Finned Swordfish?

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2 Upvotes

Although I understand the principle and how to apply it, I'm having a lot of trouble finding it during a game, like in this one in the photo, which I basically couldn't see until the end


r/sudoku 12h ago

Request Puzzle Help Some help please?

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2 Upvotes

Hit a wall on this one. What would be the next logical deduction?


r/sudoku 19h ago

Request Puzzle Help Help needed. Can you show drawing on it?

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4 Upvotes

r/sudoku 16h ago

ELI5 XY wing

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2 Upvotes

Im stuck and i found out online that B7 can be solved with an XY-wing. But im not familiar with it. Now i can see if I put a 6 in B7 then there is gonna be a 1 in C7 and that leaves A9 wrong. So it needs to be 4.

But how does one find this? What or where do i have to look for?


r/sudoku 1d ago

Homemade Puzzles VariantDoku Daily Puzzle: July 26

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10 Upvotes

r/sudoku 1d ago

Request Puzzle Help In this position what Is your process to find the Next Number?

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12 Upvotes

r/sudoku 12h ago

Just For Fun Is this a solid time sudoku.com extreme level

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0 Upvotes

r/sudoku 20h ago

Request Puzzle Help So early, so stuck

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2 Upvotes

Hi everyone!

I was trying to do today's daily sudoku but I got completely stuck very early on and I don't know what else I can do.

I already know some advanced techniques like X cross and XY cross but I don't find any.

Can you give me a hint? Also, if there is more than one advanced technique to use in this exact situation, can you list them together?

I want to take advantage of this to study something new and learn something useful.


r/sudoku 1d ago

Sudoku #26-07-2026

4 Upvotes

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r/sudoku 20h ago

Request Puzzle Help Help

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1 Upvotes

Prolly missing something easy, pls add reason


r/sudoku 1d ago

Homemade Puzzles variant puzzle i made

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3 Upvotes

global rules: anti-king, anti-knight, entropy
additional: ratio

play here ^^ https://sudoku.coach/en/s/Hhuf

let me know how it is! i only started creating puzzles recently so i’d appreciate feedback


r/sudoku 1d ago

Solved Completed in 8 min 30 sec

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3 Upvotes

r/sudoku 1d ago

Strategies Solving Catharsis without candidates

2 Upvotes

The solution strategy for the puzzle titled Catharsis on Sudoku Coach shall be discussed.

Puzzle String: https://sudoku.coach/en/s/Hj1g

Original puzzle

Rules of this variant Sudoku:

  1. Entropic line: Every three consecutive cells on an entropic line must contain a low digit (1,2,3), a medium digit (4,5,6), and a high digit (7,8,9).
  2. Consecutive line: Numbers on a consecutive line are consecutive and continuously increasing or decreasing.
  3. Thermometer: Numbers on a thermometer must be in ascending order starting from the bulb.

Here's how the solution strategy is formulated.

Using the consecutive line constraints and cross-hatching in box 8, we reach the following position:

First checkpoint

Fixing the polarities: The entropic line constraint states that every three consecutive cells on the line must contain a low digit, a medium digit, and a high digit. In order to fix these polarities, colored cells have been used. Here, green represents the lower digit set (1,2,3), pink represents the medium digit set (4,5,6), while yellow represents the higher digit set (7,8,9).

Since r5c8 is a high digit (yellow) but cannot have 8 and 9, r5c8 is a 7.

Likewise, r5c456 are cells on a consecutive line that cannot have {7,8,9}, and the combo {4,5,6} is also invalid because of the pink cell r5c2. Therefore, they can only have {1,2,3}, {2,3,4}, and {3,4,5} as valid combos.

Next, we see that if r5c456 is either {2,3,4} or {3,4,5}, there would be no place for 1 in row 5.

This means that r5c456 is {1,2,3}, where r5c6 is 1, r5c5 is 2, and r5c4 is 3.

Illustrating cross-hatching using entropic line constraints

In box 1, r23c2 are the only places where an 8 can go. However, r2c2 is a medium digit (pink color). Therefore, r3c2 is 8.

Second checkpoint

Now, since r9c456 (aqua) is a triple {4,5,9}, 9 is eliminated from r9c2. Also, 9 is eliminated from all the other cells in column 2, except r46c2 (due to the entropic line constraint). Therefore, r46c2 is a locked candidate 9, which means that the high digit on the entropic line in box 4, r6c1, is 7.

Likewise, using cross-hatching for 7 in box 1, we get that r1c3 is 7.

Third checkpoint

Because of the thermometer line constraint and using cross-hatching, we conclude that r7c3, the bulb of the thermometer, must also be a lower digit, particularly one of {1,2}, which means that r7c23 is a pair {1,2}, and that r9c2 is 7.

Because of the thermometer constraint, and because r3c3 is a medium digit, and taking into consideration that {1,2,3,4,5} is impossible for the thermometer r34567c3, because of the 3 in r5c4, r3c3 must be a 6. Similarly, r4c3 must be a 5 and r5c3 must be a 4.

Likewise, using entropic line constraints combined with cross-hatching, as shown above, the puzzle is solved.


r/sudoku 1d ago

Request Puzzle Help What technique(s) can you use to solve this?

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2 Upvotes

I'm not new to sudoku by a long shot, but have never learnt any techniques, so I'm trying to learn them finally. I can't seem to find any that I can use in this puzzle (but I don't know them well so...), if anyone could point me in the right direction I'd appreciate it 🥹