Image SEO King

I start with an audit. I crawl the site using Screaming Frog or Sitebulb and export all images. I look for three things: filenames (are they descriptive or IMG_001.jpg), alt text (present and useful or stuffed), and file size (anything over 300KB flagged). For my last e-commerce client with 15,000 product images, 68% had default filenames like "chair.jpg" and 40% had no alt text. I prioritise the product pages and blog posts that get the most organic traffic. For each priority image, I rename the file to a concise description of what is in the photo, using hyphens: "red-leather-office-chair.jpg". Then I write [alt text](/alt-text/) that describes the image and its function on the page: "Red leather office chair in a bright office with a potted plant." I keep it under 125 characters. Next I compress and convert. I use Squoosh to process batches. A 1.2MB JPEG becomes a 180KB WebP at 80% quality with no visible difference. I also create srcset versions for 480px, 768px, and 1200px widths so mobile users don't load the desktop-sized file. The result: the product page's total image weight dropped from 4.2MB to 680KB. Page load time went from 3.8 seconds to 1.1 seconds. I then submit an [image sitemap](/image-seo/) via Yoast to help Google discover the new files. Finally, I check structured data: for product images, I add product markup with image references. That's the decision rule: if the image is on a product or recipe page, add structured data. I've seen a measurable bump in Google Images visibility from sitemaps and schema combined. If you need high-resolution for zoom, use the picture element with sources for different contexts, but always compress the base file.

The most common mistake is stuffing alt text with keywords. I've seen alt text like "best SEO tips image SEO king alt text". That is a waste. John Mueller has said it does not help and harms accessibility. Describe the image: "Person typing on a laptop with SEO notes on a whiteboard." Another watch-out: uploading a 4000px image and relying on CSS to shrink it. The browser still downloads the full file. Always resize to the maximum display size before uploading. For responsive images, use srcset with widths. Also, do not put images on irrelevant pages. A photo of a cat on a page about dog training confuses the context. Google uses surrounding text, so if the page is about dog training, the image should match. Edge case: what about purely decorative images? Use CSS background instead of <img> tags, or set alt="" so screen readers skip them. Another watch-out: lazy loading everything. Lazy loading can hurt LCP if the hero image is lazily loaded. Set loading="eager" on the first visible image. Also, do not forget width and height attributes. Without them, the browser cannot reserve space, causing layout shift. Core Web Vitals penalise that. Finally, a decision rule on compression: if the file size is over 100KB for a typical [blog image](/blog-seo/), compress it further. For photographs, 80% WebP is fine. For screenshots with text, use PNG or lossless WebP to avoid blurriness.

I used to think image SEO was only about alt text. I ignored filenames, file sizes, and image sitemaps. For a travel blog I managed, I spent hours writing alt text but the images were 2MB each and had names like DSC_3456.jpg. The site was slow, and Google Images traffic was almost non-existent. After I renamed files, compressed them to WebP, and added an image sitemap, traffic from Google Images increased by 30% in two months. I also wasted time writing keyword-dense alt text. I used to craft alt text like "best SEO tips image SEO king". It was unnatural and didn't help. Now I keep it descriptive: "A laptop with SEO dashboard on screen". I also used to upload high-resolution PNG images thinking quality was paramount. But a 200KB WebP at 80% quality looks identical on screen and loads three times faster. I also neglected image sitemaps for a large e-commerce client. After adding one, Google indexed over 2,000 additional product images within weeks. Another admission: I used to forget width and height attributes, causing layout shift. It took a Core Web Vitals penalty to fix that. Now I always include them. Finally, I assumed all browsers supported WebP, but Safari on older versions didn't. I now use <picture> with a JPEG fallback. Writing good [seo copywriting](/seo-copywriting/) for alt text and page copy around images matters more than I initially thought.