Privacy Policy
Last updated: October 31, 2025
Privacy-First Design
CoreVitals.io is built with privacy as a core principle. We don't track you, we don't collect your data, and we don't use cookies or analytics. All performance testing happens in your browser.
Introduction
CoreVitals.io ("we," "our," or "us") is committed to protecting your privacy. This Privacy Policy explains how we handle information when you use our Core Web Vitals testing tool.
TL;DR: We don't collect, store, or share any personal information. Your test results are stored locally in your browser using localStorage and never leave your device.
Information We Don't Collect
Unlike most websites, CoreVitals.io does NOT collect:
- ✗Personal information (name, email, phone number, etc.)
- ✗IP addresses or device information
- ✗Cookies or tracking pixels
- ✗Analytics or usage statistics
- ✗URLs you test (they stay in your browser only)
- ✗Test results or performance data
How the Tool Works
CoreVitals.io is a client-side application that works entirely in your browser:
- You enter a URL to test
- Your browser sends a request to Google's PageSpeed Insights API (not our servers)
- Google returns the performance data directly to your browser
- We display the results to you
- Results are stored in your browser's localStorage (on your device only)
We never see or store any of this data on our servers.
Local Storage (Your Browser)
To provide historical tracking features, we store your test results in your browser's localStorage. This data:
- Stays on your device only (never sent to our servers)
- Can be cleared by clearing your browser data
- Is accessible only by you on your device
- Is not shared with any third parties
Third-Party Services
CoreVitals.io uses the following third-party services:
Google PageSpeed Insights API (Required)
We use Google's PageSpeed Insights API to fetch Core Web Vitals data. When you test a URL, our server proxies the request to Google.
Data Sent: The URL you want to test (publicly accessible website)
Purpose: Core functionality (performance testing)
Google's Privacy Policy
Anthropic Claude via Vercel AI Gateway (Optional)
When you click "Get AI-Powered Advice", we use Anthropic's Claude model via Vercel AI Gateway to provide personalized performance recommendations.
Data Sent: Your test results and questions
When: Only when you explicitly click the AI advisor button
Optional: You can use the entire tool without AI
Retention: Anthropic may retain data for 30 days (abuse monitoring)
Vercel (Hosting)
This site is hosted on Vercel. They may collect basic server logs (IP addresses, request times) for security and performance purposes. We do not have access to this data. Review Vercel's Privacy Policy .
Your Rights
Since we don't collect or store your personal data, there's nothing for us to access, modify, or delete. However, you have complete control over:
- Your browser's localStorage (clear it anytime via browser settings)
- Whether you use this tool (no account required, no obligation)
- What URLs you choose to test
Children's Privacy
CoreVitals.io is a technical tool intended for web developers and site owners. We do not knowingly collect information from anyone, including children under 13. Since we don't collect personal data, there are no special considerations for children's use.
Changes to This Policy
We may update this Privacy Policy from time to time. Any changes will be posted on this page with an updated "Last updated" date. Since we don't have your contact information, we can't notify you directly of changes.
Contact Us
If you have questions about this Privacy Policy, you can email us at privacy@corevitals.io.
Summary
CoreVitals.io respects your privacy by not collecting any data about you or your usage.
- No tracking - We don't use cookies, analytics, or tracking pixels
- No data collection - Test results stay in your browser only
- No accounts required - Use the tool anonymously, no sign-up
- Full control - Clear your localStorage anytime