Thunder vs Booster Page Speed Optimizer

Detailed Breakdown

Third-Party Script Handling

This is where Thunder and Booster differ the most. The average Shopify store runs 15-25 third-party app scripts — review widgets, email popups, analytics trackers, chat widgets — and these are responsible for the majority of speed issues.

Thunder scans every installed app, measures each script's impact on page load time, and gives you a report showing exactly which apps are the worst offenders. It then optimizes how those scripts load — deferring non-essential ones, reducing their blocking time, and prioritizing critical functionality. This is Thunder's core differentiator and directly addresses the most common cause of slow Shopify stores.

Booster applies general-purpose optimizations — lazy loading, preloading, caching — but doesn't specifically analyze or target third-party app scripts. If your speed problem is caused by a particularly heavy app (like some review or loyalty apps), Booster won't identify or fix it.

Core Web Vitals Monitoring

Thunder includes built-in Core Web Vitals monitoring (LCP, INP, CLS) directly in your Shopify dashboard. You can track your scores over time and see how optimizations affect real user metrics. As of late 2025, LCP and INP are "Baseline" metrics supported across all major browsers — making CWV monitoring more important than ever.

Booster doesn't offer Core Web Vitals monitoring. You'd need to check speed testing tools or Google Search Console separately, which most merchants don't do regularly.

Caching & Network Optimization

Booster offers browser caching controls and DNS prefetching — techniques that speed up repeat visits and reduce DNS lookup times. These are genuinely useful optimizations that Thunder doesn't currently include as dedicated features.

That said, Shopify's CDN already handles most caching effectively, so the practical impact of additional browser caching varies by store. For stores with heavy repeat traffic, Booster's caching features can provide a noticeable improvement.

Value Proposition

Booster is hard to beat on price — it's completely free. For stores with simple speed issues and few installed apps, it provides solid value at zero cost. Thunder's paid plans offer significantly more diagnostic power and deeper optimizations, but the free plan includes enough to show you whether app bloat is your main issue.

If you're unsure where to start, try Thunder's free plan to diagnose what's slowing your store, then decide if the paid features are worth it. You can always switch to Booster if your speed issues are simple enough to solve with basic lazy loading and caching.