Core Web Vitals
Core Web Vitals is Google's set of real-user measures for page loading, response to input, and visual stability. The current measures are LCP, INP, and CLS.
Another example
A team reviews 28 days of mobile data at the 75th percentile for each route. It reports LCP, INP, CLS, and sample coverage separately. One local Lighthouse run is a lab test, not real-user Core Web Vitals data.
Main parts
- 01LCP
- 02INP
- 03CLS
Use it when
Use this name for the official metric set and its written real-user thresholds.
Do not use it when
Do not treat these measures as a full test of accessibility, business success, or every kind of performance.
Name used in code
LCP + INP + CLS at p75 Before you ship
Check the runtime and version, integration limits, dependencies and licenses, and platform support. Verify security, failure, speed, monitoring, deploy, support owner, upgrade path, and rollback.
Outcome: Use or review Core Web Vitals as a technical building block that the team can maintain. User context: A team reviews 28 days of mobile data at the 75th percentile for each route. It reports LCP, INP, CLS, and sample coverage separately. One local Lighthouse run is a lab test, not real-user Core Web Vitals data. Technology or engineering concept: Core Web Vitals. Why it fits: Use this name for the official metric set and its written real-user thresholds. Do not use it when: Do not treat these measures as a full test of accessibility, business success, or every kind of performance. Engineering fit: Define where it runs and which version to use. Set its job, interfaces, data flow, dependencies, supported systems, security, and speed limits. Explain how it fits the current stack. Lifecycle safeguards: Check dependency health and licenses. Add monitoring and a fallback. Name the upgrade owner. Do not add a second tool for the same job without a measured benefit. Acceptance criteria: A small integration proves the needed behavior. Test compatibility, security, failure, and performance. Document deploy, upgrade, support, and rollback steps. Evidence and limits (evidence boundary): It is official for that source. Other platforms or teams may use the term in another way. Unknowns to confirm: Current stack, runtime and version rules, target systems, dependency owner, performance budget, support period, and migration limits.
Check this request
Review the current use of Core Web Vitals. Definition: Core Web Vitals is Google's set of real-user measures for page loading, response to input, and visual stability. The current measures are LCP, INP, and CLS. Release checks: Check the runtime and version, integration limits, dependencies and licenses, and platform support. Verify security, failure, speed, monitoring, deploy, support owner, upgrade path, and rollback. Before changing code, report the evidence you found, gaps, severity, and the smallest safe fix.