Performance Metrics · AuditJet Glossary
Speed Index
A metric that measures how quickly the visible content of a page is visually populated during load — lower is faster.
Speed Index is calculated from a video capture of the page loading and represents the average time at which visible parts of the page are displayed. It weights how fast each portion of the viewport becomes visually complete. Speed Index is a Lighthouse metric but is less directly tied to user experience than Core Web Vitals.
Related terms
The time from page navigation start until the largest image or text block visible in the viewport has finished rendering.
The time from page navigation start until any text, image, non-white canvas, or SVG is first rendered on the page.
An open-source automated auditing tool from Google that measures web page performance, accessibility, SEO, and best practices.
Frequently asked questions
What is Speed Index?
A metric that measures how quickly the visible content of a page is visually populated during load — lower is faster.
How does AuditJet measure Speed Index?
AuditJet runs automated Google Lighthouse audits that surface Speed Index scores alongside actionable fix guidance. You can track Speed Index trends across all your pages and receive alerts when the metric regresses.
Monitor Speed continuously
AuditJet tracks Core Web Vitals on a schedule with revenue impact alerts — powered by Google Lighthouse and Google PageSpeed Insights.
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