Web Vitals
Track Core Web Vitals metrics that impact SEO and user experience
Web Vitals
Web Vitals tracks Google's Core Web Vitals — the metrics that directly affect your search rankings and user experience. PubPerf monitors these metrics from real users and provides color-coded assessments so you can quickly identify pages that need attention.
Metrics & Thresholds
Each metric is color-coded based on Google's recommended thresholds:
LCP (Largest Contentful Paint)
Measures loading performance — when the main content of the page finishes rendering.
| Rating | Threshold |
|---|---|
| Good | ≤ 2.5 seconds |
| Needs Improvement | ≤ 4.0 seconds |
| Poor | > 4.0 seconds |
INP (Interaction to Next Paint)
Measures responsiveness — how quickly the page responds to user interactions.
| Rating | Threshold |
|---|---|
| Good | ≤ 200 ms |
| Needs Improvement | ≤ 500 ms |
| Poor | > 500 ms |
CLS (Cumulative Layout Shift)
Measures visual stability — how much the page layout shifts unexpectedly during loading.
| Rating | Threshold |
|---|---|
| Good | ≤ 0.1 |
| Needs Improvement | ≤ 0.25 |
| Poor | > 0.25 |
FCP (First Contentful Paint)
Measures perceived load speed — when the first piece of content is rendered.
| Rating | Threshold |
|---|---|
| Good | ≤ 1.8 seconds |
| Needs Improvement | ≤ 3.0 seconds |
| Poor | > 3.0 seconds |
FID (First Input Delay)
Measures interactivity — delay between a user's first interaction and the browser's response.
| Rating | Threshold |
|---|---|
| Good | ≤ 100 ms |
| Needs Improvement | ≤ 300 ms |
| Poor | > 300 ms |
Dashboard Views
List View
The list view shows all your domains with their Web Vitals metrics aggregated over 24 hours. Each metric is color-coded (green, orange, red) so you can spot issues at a glance.
Detail View
Click on any domain for in-depth analysis:
- Device filtering — View All, Mobile, or Desktop data separately.
- Time range selection — Analyze over different time windows.
For each metric, the detail view provides:
- Line chart — Metric values over time to identify trends.
- Bar chart — Distribution of values to understand the spread.
- Group bar chart — Breakdown by different dimensions.
Top Element Drill-downs
Identify exactly which page elements cause poor scores:
- Top LCP Elements — Which elements take longest to render.
- Top INP Elements — Which interactions are slowest.
- Top CLS Elements — Which elements cause the most layout shift.
Why Web Vitals Matter
Google uses Core Web Vitals as a ranking signal. Pages with poor Web Vitals may rank lower in search results, directly impacting your organic traffic and revenue. Monitoring these metrics helps you maintain good search visibility and deliver a fast, stable user experience.