Understanding Challenges of INP for Core Web Vitals (CWV) and How To Improve Your Score

Core Web Vitals (CWV) have long caused headaches for Publishers. In March 2024, Google are set to replace FID (First Input Delay) with Interaction to Next Paint (INP), as one of the three Core Web Vital metrics.

For those that don’t know, CWV are a set of specific factors that Google considers important in a webpage’s overall user experience. The performance of a website is not just about how quickly it loads, but also about how it interacts with users.

This is what Core Web Vitals measures, and where Interaction to Next Paint (INP) comes into play. INP is a vital metric for any Publisher wanting to understand a website’s responsiveness and interactivity.

For Publishers, optimising INP is going to be essential moving forward (as if you needed something else to worry about!), as it directly impacts your users experience, website bounce rates, and pageviews and therefore — ad revenue.

This article aims to delve into the complexities of INP, its correlation with user engagement, and how Content Ignite’s technology can help you enhance your site’s performance.

The Importance of INP in Web Performance

INP delays are categorised into three phases: Input Delay, Processing Time, and Presentation Delay. These delays can lead to poor responsiveness, particularly noticeable when users click on page elements, like opening a section of the page that is hidden (like an accordion). INP measures the largest delay experienced during interactions like tapping, clicking, and typing.

INP’s Impact on User Engagement

A critical concern for publishers should be the correlation between INP and key metrics like bounce rates and pageviews. Users can often leave your website if it’s unresponsive, leading to increased bounce rates and a reduction in pageviews — making you less ad revenue.

Identifying and fixing INP issues is certainly challenging and requires skilled development resource to find and fix issues, especially when third-party scripts like Google Publisher Tag (GPT) and Consent Management Platforms (CMPs) impact INP.

If you are monetising your website with programmatic ads, and you have Google Ad Manager as your adserver of choice (even through a 3rd-party like Content Ignite), you need a CMP like Sourcepoint (Paid) or Ketch (free option available depending on your size) in-place. Understandably though, these CMPs and any ad script is going to have an effect on INP.

Also, if you load your ad slots simultaneously onto your website, you will get penalised by the INP metrics — so exploring your existing GPT setup is hugely important.

Strategies and Tools for Optimising INP

Utilising Google tools and information sources like Web.dev and Page Speed Insights is a good place to start…

Web.dev offers case studies and insights on the relationship between bounce rates, pageviews, and INP. There are impressive case studies such as the Trendyol case study where reducing INP by 50% improved CTRs by 1% and RedBus increasing sales by 7% — stats not to be scoffed at.

For a higher-level understanding, Page Speed Insights will highlight INP at the top of it’s report and it’s a valuable tool to understand your INP score — and a little tip, also use the button toggle for comparison between your source URL and origins to see any major differences — which should increase the speed to solving any existing problems.

We’d also suggest the Core Web Vitals Extension to aid your research whilst browsing through your website to give you more understanding around INP metrics.

Tools like Lighthouse and WebPageTest won’t particularly help you with INP, you need Real-Time User Monitoring (RUM).

For a lower-level understanding, using Performance tab in Chrome Developer Tools, especially combined with activating CPU throttling, offer insights into desktop and mobile performance whilst testing in a desktop environment. Adding the web-vitals.js script to your pages can also set up to send data to Google Analytics 4 for deeper analysis around which specific pages are being affected by INP and which elements of your web page are causing those issues.

How Content Ignite help you with INP with regards to on-page Advertising

1. Ad Loading Optimisation: Content Ignite addresses the issue of loading too many ads simultaneously by implementing lazy loading, ensuring ads load as they come into view. Each of our ad units has a simple toggle to turn on Load In-View (with refresh in-view optional)
2. Single Request Architecture (SRA): To reduce batch sizes and improve loading times, Content Ignite uses SRA, streamlining the ad loading process.
3. Script Performance Analysis: The upcoming Long Animation Frame Timing API in Chrome will help Content Ignite analyse scripts impacting INP. By using the Long Task and Long Animation APIs, Content Ignite will be able to assess third-party scripts, evaluating their value and impact on site performance.
4. Cross-department Collaboration: Content Ignite can consult and advise on how to promote collaboration across departments within your organisation to evaluate the necessity and performance impact of third-party scripts, ensuring only essential scripts are used.