State of Website Bottlenecks 2026: Proprietary Study

Executive brief

Key takeaways

• 68% of analyzed sites had an LCP over 2.5s on mobile.
• Marketing tags delay interactivity (INP) by an average of 150ms.

Modern web performance is frequently hindered by recurring patterns. We evaluated 5,000 B2B and B2C sites in the first half of 2026 to map where bottlenecks are most frequent.

Evidence: The analysis focused on the 75th percentile of field data (CrUX) cross-referenced with Remountly laboratory evaluations.

Limitation: Results are an aggregated average. The revenue impact of each bottleneck must be tested individually, depending on traffic and intent.

The Largest Contentful Paint (LCP) Challenge

We observed that 68% of sites fail the LCP metric on mobile devices. The main hypothesis is the unoptimized loading of images and render-blocking CSS.

Recommended Action: Inspect the hero section. Apply fetchpriority="high" to the main image. Verify if LCP improved in lab tests and monitor the field data.

Interaction to Next Paint (INP)

With the transition to INP, it is clear that long tasks block user response. Over 45% of the sample had an INP exceeding 200ms, largely due to heavy third-party script initialization.

Recommended Action: Defer non-critical scripts to browser idle times.

Conclusion

Bottlenecks persist not due to a lack of technology, but the accumulation of technical debt. Resolve core metrics and monitor stability after each deployment. Use Remountly's continuous auditing tools to pinpoint critical pages where these issues occur.

Direct answers

Frequently asked questions

What is the methodology of this study?

We analyzed anonymized data from 5,000 properties evaluated by Remountly between January and June 2026.