Accessibility

This Sudoku board is built to be played with a keyboard and a screen reader, not just with a mouse and working eyes. This page says exactly what that means, and where it still falls short.

The board is real HTML, not a picture

Each of the 81 squares is a genuine <button> with its own label, so a screen reader can read the grid square by square. Moving across row three announces “Row 3, column 1, clue 4”, “Row 3, column 2, empty”, and so on — position first, then contents, so you always know where you are before you are told what is there.

This matters more than it sounds. Most free Sudoku sites draw their grid onto a <canvas>, which is a single image as far as assistive technology is concerned: there are no squares to move between and nothing to read. A board drawn that way cannot be played without sight at all, however good the rest of the site is.

Playing with the keyboard alone

• Arrow keys move between squares.
• 1 to 9 places a digit. Typing the same digit again clears it.
• Backspace or Delete empties the square.
• N switches pencil-note mode on and off.
• Tab reaches every square, the number pad, and each control. A skip to content link is the first thing in the tab order on every page.

Nothing on the board requires a mouse, a drag, a long press, or a gesture, and no action is on a time limit. The clock measures your solve; it never ends the game.

What gets announced

A wrong digit turns red, which is no use if you cannot see it — so the board also says so: “That digit is wrong. 1 of 3 mistakes used.” Finishing announces the result and the final score. Hints are announced in full, naming the technique and explaining the step, rather than silently filling a square.

Colour and contrast

Colour is never the only signal. A given clue differs from a digit you placed by weight and colour together; a wrong digit is announced as well as tinted; the selected square is marked by a filled background rather than a hue alone.

Every text and background pair on the board and the page chrome was measured against WCAG AA (4.5:1 for body text). The lowest reading is 4.98:1 in the light theme and 5.93:1 in the dark one; headings reach 9.35:1 and 14.01:1 respectively. Both themes pass. The theme follows your system setting unless you override it with the toggle in the header.

Structure

Every page has one <h1>, headings in order, and real landmarks — <main>, <nav> and <footer> — so a screen reader can jump straight to the content. Every image carries alternative text. The page language is declared, and the French pages declare French.

Where it still falls short

Said plainly, because a statement that only lists successes is not much help:

• The nine technique guides are English only. A French reader following a hint reaches an English page.
• The worked diagrams on those guides are decorative markup with a text explanation beside them. The explanation carries the reasoning, but the diagram itself is not separately described.
• The printable PDFs are laid out for paper. They are not a good reading experience in a screen reader — the board on this site is the accessible route.
• There is no separate high-contrast theme beyond the light and dark ones.

Tell us what we got wrong

If something here is inaccurate, or the board fights your screen reader, that is a bug and we want to hear about it. Get in touch and say what you were using — it is the fastest way to get it fixed.