What is Core Web Vitals: INP? Definition & Examples

What is Core Web Vitals: INP?

Understanding Core Web Vitals: INP in E-commerce

Quick Definition

Interaction to Next Paint (INP) is a Core Web Vitals metric measuring page responsiveness by tracking the latency of user interactions. It captures the time between a user's first interaction (click, tap, keyboard press) and the moment the browser renders the next visual update, indicating how quickly a webpage responds to user input.

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Understanding Interaction to Next Paint (INP)

Technical Definition

INP measures the time between a user interaction and the browser's next visual update, representing the perceived responsiveness of a webpage. Unlike other metrics, INP considers the slowest interaction during page load, providing a comprehensive view of user experience.

INP Performance Thresholds

Performance Category	INP Range (ms)	User Experience Impact
Good	0-200	Responsive, smooth interactions
Needs Improvement	200-500	Noticeable lag, potential frustration
Poor	500+	Significant delays, high bounce risk

Common Causes of Poor INP

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Long JavaScript Execution: Complex scripts blocking main thread
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Large DOM Size: Excessive HTML elements slowing rendering
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Inefficient Event Listeners: Poorly optimized interaction handlers
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Heavy Third-Party Scripts: External libraries consuming processing resources

Optimization Strategies

Code Splitting

Reduce initial JavaScript payload by loading code incrementally

Debounce Interactions

Limit rapid successive event triggers

Web Workers

Offload heavy computations from main thread

Minimize DOM Complexity

Simplify page structure and reduce nested elements

E-commerce Performance Implications

For online stores, INP directly impacts conversion rates. Slow interactions can lead to cart abandonment and reduced customer trust. Tools like Growth Suite help merchants understand and optimize user engagement by providing detailed performance insights that go beyond traditional metrics.

By proactively monitoring and improving INP, e-commerce businesses can create smoother, more responsive shopping experiences that keep customers engaged and increase the likelihood of purchase.