Stroke
Shape capture
The app records the path of your handwritten strokes rather than just looking at a static image.
Handwriting recognition
How Handwriting Recognition Works
SudoSketch lets you write numbers directly into the Sudoku grid, then converts your handwriting into digital Sudoku entries.
Writing into the grid
When handwriting mode is enabled, SudoSketch captures your stroke path inside the selected Sudoku cell. That input can come from Apple Pencil, a stylus or your finger depending on the device.
The app then compares the shape of your strokes against digit patterns and your own saved calibration samples. The aim is to recognise how you naturally write numbers, not force everyone into the same perfect schoolbook digits.
You can still correct recognition mistakes manually. That matters because handwriting is messy, humans are inconsistent, and the number 5 has been personally victimising recognition systems since the dawn of computing.
Recognition ingredients
Profile
Calibration
Your confirmed samples help the app understand your version of each digit.
Control
Manual override
If recognition gets a digit wrong, you can correct it and keep solving.
Why this matters for Sudoku
Sudoku is naturally a writing puzzle. Many players think on the grid, especially when using notes and candidates. Handwriting input keeps that paper-like rhythm while retaining digital tools such as undo, highlighting and mistake checking.
This is one of SudoSketch’s clearest advantages. Most online Sudoku sites treat input as button pressing. SudoSketch treats writing as part of the solving experience.
How Handwriting Recognition Works FAQ
Can I use Apple Pencil?
Yes. SudoSketch supports Apple Pencil handwriting input on compatible iPad browsers.
Can I use my finger?
Yes. Finger and stylus input are supported where the browser provides suitable pointer input.
Can I train the recognition?
Yes. Calibration lets you create handwriting samples so SudoSketch can better recognise your digits.