The Chatbot "Performance Tax": Which Vendors Aren’t Ruining Our CWV?

[douglaskarr]

Our platform passes Core Web Vitals (CWV) out of the gate on both mobile and desktop. However, we’re seeing third-party chatbots wipe out those scores instantly. I recently audited a bot with a CSS file larger than our entire site's CSS, zero image compression, and massive CLS issues that led to a direct hit in local search traffic. Shift Digital has published research that shows that if your site fails Core Web Vitals, you’re wasting $30 of every $100 in advertising spend.

We know these tools are vital for lead capture, but the trade-off shouldn't be the technical health of a site. I’m looking for recommendations for solutions that actually respect modern standards... not the players out there with the biggest marketing budget. I don't want to use this thread to crap on anyone... just genuinely interested in who might be crushing both user experience without ruining page speed.

We'd love to recommend a provider if they meet these 5 baseline checks:

• Asynchronous Loading: Does the script load without blocking the main thread or use "Interaction-Only" initialization?
• Asset Weight: Is the total payload for CSS/JS under 100KB, or is it a bloated mess?
• Image Optimization: Are avatars and icons served via CDN in next-gen formats (WebP) and properly scaled?
• Visual Stability: Do they use reserved containers to prevent Cumulative Layout Shift (CLS) on mobile?
• Facade Support: Can we trigger the heavy chat code via a lightweight image button rather than loading the full library on page load?

Has anyone found a provider delivering high-quality leads without the "performance tax"? I’m tired of seeing great SEO work undone by one poorly coded widget.

 

[DjSec]

You’re right that dealership sites get slow because of vendor bloat and architecture. If you check Overfuel sites even those without a Chatbot you'll still see Lighthouse showing 8–12 second mobile loads, the report will tell you exactly why and it is usually oversized hero media, multiple analytics stacks, blocking compliance scripts, large inventory payloads, and big JS bundles.

A chatbot can be lazy-loaded so it doesn’t affect initial paint, and it’s rarely the root cause. The real fix is auditing scripts, compressing media, caching inventory calls, and measuring every third-party tool before adding it.

If we’re going to call out slow sites, we should probably post the Lighthouse reports so we can look at the actual bottlenecks instead of guessing.