Using Notes

Notes (also called pencil marks or candidates) are essential for solving harder puzzles. They help you track which numbers are possible in each cell.

What Are Notes?

Notes are small numbers written in a cell to remind you of possible candidates. Instead of committing to a single digit, you mark all the options.

For example, if a cell could be 3, 5, or 7, you'd enter all three as notes.

Enabling Notes Mode

Toggle notes mode using:

  • Press N on your keyboard
  • Click the Notes button

When notes mode is active, the button appears highlighted.

Entering Notes

With notes mode enabled:

  1. Select a cell
  2. Press a number (1-9)
  3. A small digit appears in the cell

Press the same number again to remove that note.

Reading Notes

Notes appear as small digits arranged in a 3×3 pattern within the cell:

1 2 3
4 5 6
7 8 9

Each number occupies its own position, making it easy to see at a glance which candidates remain.

Why Use Notes?

Track possibilities — As you eliminate candidates through logic, remove their notes.

Spot patterns — Techniques like naked pairs become visible when you note candidates.

Avoid mistakes — Notes prevent you from forgetting valid candidates.

Enable advanced techniques — Many strategies require seeing all candidates.

Auto-Notes

Some players prefer automatic notes that show all candidates based on current constraints. Check Settings if you want this feature.

When to Note

Different philosophies exist:

Full notation — Note all candidates in every cell from the start. Thorough but time-consuming.

Selective notation — Only note cells where you're actively working. Faster but requires more mental tracking.

Progressive notation — Start without notes, add them as puzzles get harder.

Find what works for you. Most experienced solvers use notes extensively on Hard+ puzzles.

Keeping Notes Updated

The key to useful notes is keeping them current:

  • When you place a number, remove it from notes in related cells
  • When you eliminate a candidate through logic, remove its note immediately

Stale notes lead to mistakes. Stay disciplined!