For transactional email
Consider SMTP2GO for website-generated messages, form notifications, account notices, and other outbound system email.
Explore SMTP2GOAvailableFree browser-local analysis
Core Web Vitals Analyzer
SiteTend Core Web Vitals
Evaluate LCP, INP, and CLS values, identify the largest user-experience risks, and prioritize mobile and desktop improvements.
Your input stays private.Metric values are analyzed in your browser.
Enter field or lab metrics
Use values from the same page, device category, and measurement source.
Review performance risks
Address poor metrics first, then verify results on mobile and desktop.
Your analysis will appear here
Enter LCP, INP, and CLS values and select Analyze vitals.
How to evaluate
Use representative mobile and desktop data
Core Web Vitals compliance requires good LCP, INP, and CLS at the 75th percentile. Keep mobile and desktop results separate, and use this manual check to understand priorities rather than to replace field measurement.
Questions
Core Web Vitals Analyzer FAQ
What thresholds does this analyzer use?
Good values are LCP at or below 2.5 seconds, INP at or below 200 milliseconds, and CLS at or below 0.1. Poor values are above 4 seconds, 500 milliseconds, and 0.25 respectively.
When does a page pass Core Web Vitals?
All three metrics must meet their good thresholds. Official field assessment uses the 75th percentile of page loads, separated by mobile and desktop.
Where should metric values come from?
Use consistent values from a trusted field source such as the Chrome User Experience Report or a controlled laboratory test, and do not mix devices or sources.
Does SiteTend fetch or store performance data?
No. Version 1 evaluates only the values you enter, entirely in your browser.
Apply the result
From finding to verified fix
Interpret the finding
Work from the failing metric and device segment. Passing lab data does not override weaker real-user field data.
Common causes to inspect
- Slow largest-content rendering
- Long main-thread tasks during interaction
- Images, ads, or fonts shifting after layout
Practical next steps
- Keep mobile and desktop evidence separate
- Fix the largest failing contributor
- Remeasure under the same conditions and monitor field data
What this check cannot prove
Entered values are not collected from the page and cannot identify the responsible request, component, or user segment.
Recommended resources
Useful next steps for operating a website
For measuring business inquiries
Use WhatConverts to measure which marketing sources produce calls, forms, and leads. It measures outcomes; it does not fix technical website issues.
Explore WhatConvertsFor personal-data privacy
Consider Optery if exposed personal information or data-broker listings are a concern. It is a separate privacy resource, not an SEO or website-security scanner.
Explore OpterySiteTend may earn a commission if you purchase through these links, at no additional cost to you. These services are optional and separate from SiteTend's free checks.