Text first
Everything on this site is text in tables: a voice’s note, the note it leads to, the semitones between them, and the total. Every table carries a caption saying what its rows are, nothing is carried by colour alone, and nothing is drawn as a picture a screen reader cannot read.
Keyboard
Every control can be reached and operated from the keyboard, in reading order, with a visible focus ring. The calculator’s two chord inputs are ordinary text fields, and the result they produce is announced when it changes. The skip link at the top of each page goes straight to the content.
Motion and sound
Nothing on this site plays a sound, and nothing animates unless you asked it to. A new result replaces the old one in place rather than sliding in.
Contrast
Every built-in theme is checked in continuous integration for text contrast against its own backgrounds, and the theme builder reports the contrast of any palette you make before you apply it.
Telling us
If something here does not work with the way you read the web, that is a defect, and we would like to fix it.