Images typically account for 50–80% of a page’s total weight. Unoptimized images are the single biggest cause of poor Largest Contentful Paint (LCP) scores, which directly impacts both SEO and user experience.
Our general recommendation: Every site with images needs some form of optimization. The key differences between plugins are where the processing happens (your server vs. cloud), what formats they support (WebP and AVIF are essential in 2026), and how the pricing works (per-image credits vs. flat rate vs. visitor-based tiers). Pick one that matches your volume and privacy requirements.
What about Smush?
Smush is the most installed image optimizer (1M+ sites), and it has a clean interface that’s easy to use. The limitation is that the free version only offers lossless compression, which achieves roughly 5 to 15% file size reduction. That’s a real improvement, but significantly less than the 40 to 60% that lossy compression delivers. To unlock lossy mode, WebP conversion, and CDN features, you need the Pro version, which comes bundled with a full WPMU DEV membership. For sites focused purely on image optimization, dedicated tools offer more compression for less cost.