The simplest check: go back to Integrations → Image Settings in your back office. The status toggle at the top shows whether Image Boost is on or off.
For the speed proof, run a free PageSpeed Insights scan at pagespeed.web.dev on your live site. With Image Boost on, you'll see smaller total image payload (often 70-97% less), faster Largest Contentful Paint, and higher Core Web Vitals scores.
To check a single image directly, inspect its response headers in your browser's DevTools:
- Open your site in Chrome, Firefox, or Edge.
- Press F12 to open DevTools. Click the Network tab.
- Reload the page. The Network tab fills with every file the page loaded.
- Click any image row in the list (filter by Img to narrow it down).
- Look at the Headers panel on the right.
When Image Boost is active, you'll see Cloudflare cache headers like cf-cache-status: HIT and cf-resized: internal=ok/h=... — the cf-resized header confirms the image was transformed at the edge.
When Image Boost is inactive, you'll see the header x-image-boost: bypass. That's the Worker telling you it served the original file untransformed.
The image URL itself routes through https://images.sitestakes.com/img/... either way — the URL doesn't change when you activate or deactivate, which keeps your SEO stable. Only the response behind that URL changes.