lower is better

https://github.com/frarees/typometer

Typometer

Typometer is a tool to measure and analyze the visual latency of text editors.

Editor latency is the delay between an input event and a corresponding screen update — in particular, the delay between keystroke and character appearance. While there are many kinds of delays (caret movement, line editing, etc.), typing latency is a major predictor of editor usability.

Check the article typing with pleasure to learn more about editor latency and its effects on typing performance.