What Is Image SEO? Alt Text, File Size and Image Search

In plain English

Two separate goals sit under this. One is not letting images slow the page down. The other is making images discoverable in their own right.

The first is worth doing on every site. The second matters most where the image is the product: recipes, interiors, fashion, travel, anything visual.

What to know

Weight

Compress properly and use modern formats. Images are the most common cause of slow pages.

Dimensions

Serve the size actually displayed, and set width and height so layout does not shift.

Alt text

Describe the image for someone who cannot see it. That is also what makes it indexable.

Context

Filenames, captions and surrounding copy tell search engines what the image shows.

Why it matters

Image weight is usually the single largest performance problem on a content site, so this is often the fastest Core Web Vitals win available. For visual businesses, image search is also a real traffic channel that most competitors ignore entirely.

Common mistakes

×Uploading full-resolution photographs straight from a camera or phone.

×Stuffing keywords into alt text instead of describing the image.

×Leaving alt text empty on images that carry meaning.

×Lazy-loading the main hero image, which delays the largest paint.

FAQs

Does alt text help rankings?

It helps accessibility and image search, and it gives context. It is not a place to put keywords.

Which format should I use?

WebP or AVIF for photographs, SVG for logos and diagrams.

WRITTEN BY TARIQ SALLAM

Marketing Consultant. Entrepreneur. Content Creator.

I'm a marketing consultant, entrepreneur and content creator. I help businesses grow through practical marketing, websites, SEO, content and AI.

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