Tap it out

Hold the spacebar for a dah, tap it for a dit. What you send is decoded as you go, at the speed you set.

The timing is what you are actually practising

A dit and a dah are distinguished only by length — three to one — and the gaps carry as much meaning as the marks. That is why sending is harder than reading: the rhythm has to be right before the letters are legible to anyone else.

Live decode is the feedback that teaches

Seeing what you actually sent, rather than what you meant to send, is the entire value of practising on a key with a decoder attached. A dah held slightly short reads as a dit, and you will not notice unaided.

Questions

How fast is 20 words per minute?

A dit is 1200 divided by the speed in words per minute, so at 20 WPM a dit is 60 milliseconds and a dah is 180. The standard word is PARIS because it is exactly 50 units long, which is what makes words per minute a precise measure of morse rather than an approximate one.

What is Farnsworth spacing?

Sending the characters at full speed while stretching the gaps between them. It exists because learning morse slowly teaches you to count dits, and that habit has to be unlearned before any real speed is possible. Learning the character sounds at 18 WPM with long gaps means never having to relearn them.