In plain English
An automated laboratory tool that audits a page in a controlled test for areas including performance, accessibility, best practices and SEO.
Why it matters
This instrument can help answer a focused measurement question when it is connected to a real objective and read alongside relevant context.
Example
A small organisation records this signal for a defined page and period, then compares it with related instruments before deciding whether to investigate a change.
Common misunderstanding
Lighthouse results can vary between tests because conditions vary. A score is diagnostic evidence, not proof of every visitor’s experience or rankings.