Intermediate
How to monitor performance with speed insights on Vercel
Quick Answer
Vercel Speed Insights provides real-time performance monitoring for your deployed applications using Core Web Vitals metrics. Enable it through your Vercel dashboard, install the analytics package, and monitor key performance indicators like LCP, FID, and CLS.
Prerequisites
- A Vercel account
- A deployed project on Vercel
- Basic understanding of web performance metrics
- Project with at least some traffic
1
Access your Vercel project dashboard
Log into your Vercel account and navigate to the project you want to monitor. Click on your project name from the dashboard to access the project overview page.
Tip
Make sure your project has been deployed and is receiving traffic for meaningful insights
2
Enable Speed Insights
In your project dashboard, click on the Analytics tab in the navigation menu. Look for the Speed Insights section and click Enable Speed Insights. This will activate real-time performance monitoring for your application.
Tip
Speed Insights may take up to 24 hours to start showing data after enabling
3
Install the Vercel Analytics package
In your project directory, install the Vercel Analytics package:
For Next.js projects, also install the specific Next.js package:
npm install @vercel/analyticsFor Next.js projects, also install the specific Next.js package:
npm install @vercel/speed-insightsTip
The package is lightweight and won't impact your bundle size significantly
4
Configure Speed Insights in your application
Add the Speed Insights component to your application. For Next.js, add it to your
_app.js or _app.tsx file:import { SpeedInsights } from '@vercel/speed-insights/next';
export default function MyApp({ Component, pageProps }) {
return (
<>
>
);
}Tip
For React apps, import from '@vercel/speed-insights/react' instead
5
Deploy your updated application
Commit and push your changes to trigger a new deployment on Vercel. You can also manually deploy using:
Wait for the deployment to complete successfully.
vercel --prodWait for the deployment to complete successfully.
6
Access Speed Insights dashboard
Return to your Vercel project dashboard and click on the Analytics tab. Select Speed Insights to view your performance data. You'll see Core Web Vitals including Largest Contentful Paint (LCP), First Input Delay (FID), and Cumulative Layout Shift (CLS).
Tip
Data will populate as real users visit your site - synthetic testing data isn't included
7
Analyze performance metrics
Review the performance timeline and identify pages with poor performance scores. Click on individual pages to see detailed breakdowns. Use the Filter options to segment data by device type, connection speed, or geographic location for deeper insights.
Tip
Focus on pages with high traffic first, as they have the most impact on user experience
8
Set up performance alerts
In the Speed Insights dashboard, click on Settings and configure alerts for performance regressions. Set thresholds for Core Web Vitals and choose notification methods. Enable Deployment Protection to prevent deployments that significantly degrade performance.
Tip
Start with conservative thresholds and adjust based on your baseline performance
Troubleshooting
Speed Insights not showing any data after 24 hours
Verify that the
@vercel/speed-insights package is properly installed and the SpeedInsights component is correctly imported in your app. Check that your site is receiving real user traffic, as Speed Insights only collects data from actual visitors.Performance metrics seem inaccurate or inconsistent
Ensure you're using the latest version of the Speed Insights package with
npm update @vercel/speed-insights. Remember that metrics reflect real user experiences, which can vary based on device performance, network conditions, and geographic location.Speed Insights feature not available in project settings
Speed Insights requires a Vercel Pro plan or higher. Upgrade your account plan or contact Vercel support if you believe you should have access. Some legacy projects may need to be migrated to newer Vercel infrastructure.
High Cumulative Layout Shift (CLS) scores reported
Check for images without explicit
width and height attributes, dynamically injected content, or web fonts causing layout shifts. Use the Page Details view in Speed Insights to identify specific elements causing layout shifts and optimize them accordingly.Ready to get started with Vercel?
Put this tutorial into practice. Visit Vercel and follow the steps above.
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