Understanding INP
The Interaction to Next Paint (INP) metric is crucial for evaluating a website’s responsiveness, focusing on how quickly a site shows visual feedback after user inputs like clicks and keystrokes. It measures the delay before visual changes, highlighting the importance of immediate feedback for a good user experience. INP values the promptness of a page’s reaction, underlining that even complex actions should have swift initial responses to keep users informed. The metric’s goal is to reduce the time between a user’s action and the visual update, ensuring the site feels responsive.
Effective responsiveness in web design ensures that a webpage quickly reacts to user actions, providing immediate visual confirmation of their interactions. This rapid feedback could indicate the successful addition of an item to a shopping cart, the activation of a mobile menu, or the processing of login details by a server, offering users a seamless and engaging online experience.
Certain user actions require more processing time, emphasizing the need for immediate visual cues to signal activity. INP focuses on the delay before the browser updates visually, aiming not to track the full process but rather the initial responsiveness. Its goal is to reduce the wait time for visual feedback after user interactions, enhancing the perceived responsiveness of the site.
How it’s being measured
INP measures the delay of visual feedback from user interactions, which could involve various events like clicks or taps, driven by JavaScript, CSS, or browser controls. It calculates the longest duration among these event handlers, starting from the user action to the display of the next frame, indicating responsiveness.
What is the good the bad and the ugly
A good INP score, indicating responsive web pages, is 200 milliseconds or less, as measured across mobile and desktop devices at the 75th percentile of page loads. Scores between 200 and 500 milliseconds suggest a need for improvement, while anything over 500 milliseconds reflects poor responsiveness.
What is an interaction
An interaction in the context of INP is mainly driven by user actions such as clicking with a mouse, tapping on a touchscreen device, or pressing a key. While JavaScript often powers these interactions, non-JavaScript controls like checkboxes and CSS-driven elements also contribute. INP specifically measures these types of interactions, excluding actions like hovering or general scrolling, but includes keyboard-initiated scrolling due to its potential to trigger measurable events. Interactions can occur within the main document or iframes, affecting how INP is measured across different page elements.
Is an old metric FID the same or similar to INP
INP and FID both measure responsiveness but differ in scope. FID captures delay from the first interaction only, focusing on initial load responsiveness. INP expands on this by assessing delays in all interactions throughout a page’s life, including the time to handle events and the browser’s next frame paint. This makes INP a broader measure of a site’s overall responsiveness, not just the first impression.
Optimize your site for better INP
To address poor INP, start by analyzing data to confirm if your site’s INP needs improvement. Once identified, use lab tools to diagnose and pinpoint the reasons behind slow interactions, guiding you towards effective solutions.
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Wrap up
Improving INP involves understanding your site’s current performance, diagnosing issues through lab analysis, and implementing targeted solutions. Start by collecting INP data to identify areas needing improvement, then analyze specific interactions causing delays. This comprehensive approach ensures a smoother user experience across your site.
