The technical landscape of the web has significantly shifted over the past two years. Between the replacement of one Google metric by another, the rise of accessibility standards, and the emergence of generative AI in search results, the benchmarks used to evaluate a website are no longer quite the same as before. This article reviews the technical and editorial parameters that truly impact a website’s performance in 2024.
Interaction to Next Paint: the metric replacing First Input Delay
Since March 12, 2024, Google has replaced First Input Delay (FID) with Interaction to Next Paint (INP) in its Core Web Vitals. The difference is structural: FID only measured the latency of the very first interaction of a visitor, while INP assesses the responsiveness of each interaction throughout the session.
An INP score is considered good when it remains less than or equal to 200 ms. Beyond that, Google considers that the site penalizes user experience. Tools like PageSpeed Insights have been updated to reflect this change.
In practice, a site may have achieved a good FID score for years and find itself penalized by INP without having modified a single line of code. Heavy JavaScript scripts, poorly optimized event handlers, and costly DOM renders are the main culprits of degraded INP. To delve deeper into these technical aspects, Zone Webmaster resources detail the characteristics to monitor on a high-performing website.
Web performance gap between desktop and mobile
Recent data on the WordPress ecosystem illustrate a trend that general guides rarely mention. On desktop, the vast majority of WordPress sites now pass the “good” threshold in INP. On mobile, the situation remains significantly more varied.
This gap can be explained by several combined factors: reduced computing power of mobile devices, unstable network connections, and the weight of third-party scripts (analytics, cookie consent, widgets). A site that shows an INP of 120 ms on a laptop can easily exceed 350 ms on an entry-level smartphone.
The usual reflex is to test one’s site on their own phone, often a recent model. Field feedback diverges on this point: a test on a high-end device does not reflect the actual experience of the majority of visitors. Data from the Chrome UX Report, which aggregates measurements from real users, remains a more reliable indicator than a lab test.
Web accessibility and WCAG 2.2 standards
The WCAG 2.2, published in October 2023, have become the new reference for web accessibility. Compared to the previous version, they add criteria specifically targeting users with reduced mobility, individuals with cognitive impairments, and those navigating without a mouse.
Several countries are gradually strengthening their legal obligations around these standards. In Europe, the directive on the accessibility of products and services will come into effect in June 2025, directly affecting online commerce sites and digital services.
The most frequently overlooked points on a website often remain the same:
- Insufficient color contrasts between text and background, which tools like Contrast Checker can verify in seconds
- Lack of visible focus on interactive elements, hindering keyboard navigation
- Forms without explicit labels, making input impossible for screen readers
- Non-disableable animations, problematic for users sensitive to motion
Accessibility is no longer an optional criterion but a legal and technical parameter that also impacts organic SEO, as Google values sites that comply with good usability practices.
Generative AI in Google results: what it changes for content
Google’s AI Overviews, these AI-generated summaries displayed at the top of search results, change the game for website publishers. According to available analyses, the pages that are cited in these boxes are not always those that occupy the top organic position.
Google seems to favor content that responds in a structured and factual manner to specific queries. Structured data (schema.org), comparative tables, and short paragraphs formulated as direct answers increase the chances of appearing in these boxes.
However, the available data do not allow for a definitive conclusion about the impact of AI Overviews on click-through rates. Some studies suggest a decrease in organic traffic for simple informational queries, while transactional or highly specialized queries seem less affected.
For a website in 2024, this implies rethinking the editorial structure:
- Prioritize high-value content that AI cannot summarize in three lines
- Structure pages with clear semantic tags (H2, H3, lists, tables)
- Work on long-tail queries, which are less exposed to automated summaries
Cookie consent and GDPR compliance: an underestimated performance factor
Cookie consent banners have become ubiquitous. Their impact on the technical performance of websites is rarely measured. A poorly implemented consent banner can add several hundred milliseconds to loading time and directly degrade the INP score.
Best practices are evolving towards lighter banners, loaded asynchronously, and so-called “cookieless” approaches for analytics tracking. A site compliant with GDPR and technically optimized are not two contradictory objectives, but their reconciliation requires careful integration work.
The success of a website in 2024 does not rely on a fixed list of best practices. Google’s technical criteria are evolving (INP replaces FID), regulatory frameworks are tightening (WCAG 2.2, European directive on accessibility), and generative AI is redistributing visibility in search results. The only constant remains the need to measure, with real data, what works on one’s own site rather than relying on generic recommendations.