Great photos sell products online. They're also, almost always, the heaviest thing on every page. Get them right and your store looks beautiful, loads quickly and even picks up visitors from Google Images. Get them wrong and you've got a slow store that people leave before it finishes loading.
The good news: image problems are some of the easiest to fix. Here's what we check.
1. Use the right file type
JPG is best for photos. PNG is for graphics that need transparency or crisp text; using it for photos can make files many times bigger. SVG is ideal for logos and icons. And modern formats like WebP and AVIF produce even smaller files. If you're on Shopify, you don't need to convert anything yourself: Shopify's image CDN automatically serves WebP or AVIF to browsers that support them. Just upload a good-quality JPG.
2. Upload at a sensible size
A photo straight off a camera can be 6,000 pixels wide and 10 MB. No website needs that. As a rough guide, product images work well at around 2,000 pixels on the longest side (enough for zoom), full-width banners at about 2,400 pixels wide, and blog images at about 1,600 pixels wide. Modern themes then create smaller versions automatically for phones and tablets.
3. Compress before you upload
Run images through a compression tool first. Product photos should ideally be well under 500 KB, and often much smaller. Homepage banners are where we find the biggest problems. A 3 to 6 MB banner is common, and shrinking it is one of the quickest speed wins there is.
4. Keep shapes consistent
Pick one aspect ratio for product images, square or 4:5 for example, and stick to it. Your grids look neater, and the page doesn't jump around as images load, which helps your CLS score.
5. Lazy-load, but not everything
Images further down the page should load only when someone scrolls to them. That's lazy loading, and it saves a lot of data. The exception is the first big image, usually your hero banner or main product photo. That one should load immediately, or the page will feel slow even if everything else is quick.
6. Write alt text like you're describing it to a friend
Alt text describes an image for people using screen readers and for search engines. Good alt text is specific and natural. "Earrings" is too vague. "Earrings jhumka silver buy online best jhumka india" is stuffed and reads badly. "Oxidised silver jhumka earrings with pearl drops" is just right.
Purely decorative images, like background patterns and dividers, can have empty alt text.
7. Rename files before uploading
IMG_4021.jpg tells nobody anything. oxidised-silver-jhumka-pearl.jpg gives Google a small extra clue and keeps your media library tidy. It takes seconds.
8. Go easy on sliders
Homepage sliders load several large images at once, and most visitors never get past the first slide. One strong hero image plus a clean collection grid usually loads faster and works just as well.
9. Be thoughtful with video
Product videos can really help conversions. Keep them short, compress them, host them properly and avoid autoplaying large videos at the top of the page.
10. Check again every month
Every sale and campaign adds new banners. Once a month, check your homepage and top pages for oversized images. When a page suddenly gets slow, it's very often one forgotten 5 MB graphic.
Your quick checklist
- Photos as JPG; graphics as PNG or SVG
- Resized to sensible dimensions
- Compressed before upload
- One consistent aspect ratio
- Hero image loads immediately; everything else lazy-loads
- Descriptive alt text and file names
Two quick answers
Doesn't Shopify compress images automatically? It serves optimised formats and sizes, which helps a lot. But it can't fix an image that's badly cropped or enormous to begin with, so compressing first still makes a difference.
Does alt text actually help SEO? Yes, particularly in Google Images, and it's essential for accessibility.
If images are dragging your site down, our One-Time Speed Optimization includes compression and lazy-loading setup. Send us your link and we'll take a look.