Performance
Overall Performance Score
A weighted composite of all timing metrics. Reflects how fast a page loads and becomes usable. Directly impacts bounce rates and Google Search rankings.
90+ Good50–89 Fair0–49 Poor
Accessibility
Accessibility Score
Checks whether the page is usable by people with disabilities — screen readers, keyboard navigation, color contrast, ARIA labels. A legal compliance consideration under ADA and Section 508.
90+ Good50–89 Fair0–49 Poor
Best Practices
Best Practices Score
Checks for modern web standards: HTTPS usage, no deprecated APIs, correct image aspect ratios, browser console errors, and security headers.
90+ Good50–89 Fair0–49 Poor
SEO
Search Engine Optimization
Audits on-page SEO signals: meta tags, crawlability, font legibility, structured data, and link descriptions. Higher scores correlate with better organic search visibility.
90+ Good50–89 Fair0–49 Poor
FCP
First Contentful Paint
Time until the browser renders the first piece of content. The first visual feedback a user gets that the page is loading. Lower is better.
≤1.8s Good1.8–3s Fair>3s Poor
LCP
Largest Contentful Paint
Time until the largest visible element fully renders. A Core Web Vital used directly in Google Search ranking. One of the highest-impact metrics to optimize.
≤2.5s Good2.5–4s Fair>4s Poor
TBT
Total Blocking Time
Total time the main thread is blocked by JavaScript, preventing user interaction. High TBT makes clicks and taps feel unresponsive. Measured in milliseconds.
≤200ms Good200–600ms Fair>600ms Poor
CLS
Cumulative Layout Shift
Measures visual stability — how much page content shifts unexpectedly while loading. A Core Web Vital. Lower is better.
≤0.1 Good0.1–0.25 Fair>0.25 Poor
Speed Index
Speed Index
Measures how quickly visible content is populated during page load. Progressive rendering scores better than all-at-once rendering. Measured in seconds.
≤3.4s Good3.4–5.8s Fair>5.8s Poor