Hi, I hope someone can help me.
My website homepage and collections seem to load ok but the product pages take ages to load, to the extent that an error page sometimes comes up and Google ads aren’t showing my products becaused they say the page doesn’t exist.
My website uses the Vantage theme and I am fairly sure that the speed wasn’t an issue when I first created the site. Unfortunately at that time I didn’t resalise that large png images weren’t a good thing so I got someone to help me optimise them but they didnt reduce that much and they have since been re-sized and some changed to jpegs so all the images sizes are now fine but the product pages are still slow to load. Can anyone help me as this is costing me business. Many thanks.
Hi @Burden_Arb ,
First I suggest using webp format images they are lightweight and google also recommends them.
Second are you sure it’s the image causing the low speed, try disabling the apps and try again.
Third maybe you have enabled few section which require heavy js usage or maybe in development process you may have added any script which may cause low speed or maybe the gallery or variant picker js is not optimize well
Also make sure to check multiple products… what if you are only facing the issue with one certain products
Please share your store link so I can find the real culprit for you 
Hi, @Burden_Arb
If the rest of the site feels snappy but product pages are dragging, it’s usually because product templates are doing way more work than other pages. Product pages often include more dynamic logic, such as related products, metafields, variant logic, review widgets, and third-party app integrations, all of which increase server work and front-end rendering time.
A few key areas to check:
Review apps loading on product pages
Product pages usually have the most apps attached to them (reviews, trust badges, upsells, variant options, tracking scripts, etc.). Even if image sizes are now optimized, one heavy image can cause long load times or even intermittent errors.
Product media
Product pages tend to load slower because they include large images, product images, and videos. Use properly sized JPEG/WebP images and avoid lazy-loading the main product image. Lazy-load all content below the fold and remove unnecessary media or scripts.You can optimize manually one by one and you can use Shopify app automatic image or video optimizer like Mp - Image Optimizer pro - MP ‑ Image Optimizer Pro - Resize Compress Optimize Photos | Auto Bulk edit | Webp... | Shopify App Store
JavaScript execution
Even with optimized images, JavaScript can still block rendering. Variant logic, review widgets, sticky add-to-cart features, and analytics scripts often all load at once on product pages.