Performance3 min read
AVIF, WebP or JPEG: choosing image formats and compression settings
Images are usually the largest thing on a page. Format and compression choices routinely cut that weight in half with no visible difference.
Image SEO means giving search engines the context they cannot extract from pixels: a descriptive filename, accurate alt text, relevant surrounding content, correct dimensions and format, and structured data where applicable. Image search can be a meaningful traffic source for product, recipe and visual content.
Machine vision has improved substantially, but the textual signals remain what determines which query an image is considered relevant to. They also remain the only thing a screen reader user receives.
<!-- Poor: keyword stuffing -->
<img src="img1.jpg" alt="web development company website design agency india best">
<!-- Poor: no information -->
<img src="img1.jpg" alt="image">
<!-- Good: describes the image and its purpose -->
<img src="saas-dashboard-redesign-before-after.webp"
alt="SaaS dashboard before and after redesign, reducing the onboarding flow from five steps to two">
<!-- Decorative: intentionally empty so screen readers skip it -->
<img src="divider.svg" alt="">| Sector | Image search value |
|---|---|
| Ecommerce and fashion | High — visual discovery drives purchases |
| Recipes and food | High |
| Travel and property | High |
| Design and portfolio | Moderate to high |
| B2B SaaS | Low, except for diagrams and comparisons |
| Professional services | Low |
For sectors where it matters, add an image sitemap, use structured data with image properties, and make sure each image sits on a page with relevant content. For B2B, the return on deliberate image search optimisation is usually low — spend the effort on original diagrams instead, which earn links and citations.
Original diagrams and charts are the highest-value images most technical sites can produce. They earn links from people who reference them, they get cited by AI systems that describe them, and they demonstrate the expertise that generic stock photography actively undermines.
It affects image search relevance and contributes modestly to page context. Its primary purpose is accessibility, and writing it well serves both.
Every image needs an alt attribute. Meaningful images get a description; purely decorative ones get alt="" so assistive technology skips them.
Only if images are a significant traffic source or are loaded in ways crawlers might miss. For most sites, images referenced in the HTML are discovered normally.
Not directly, but widely-reused stock images add no unique value and no differentiation. Original images and diagrams are far more likely to earn links and citations.
ROVQIX Growth
SEO & growth team, ROVQIX
The ROVQIX growth team handles technical SEO, Core Web Vitals and AI-search visibility for the sites we build. Recommendations here are the ones we apply to client projects and to rovqix.in itself.
ROVQIXdesigns and builds production web platforms — Next.js front ends, Node.js APIs and the infrastructure behind them. Tell us what you're building and we'll scope it with you.
Images are usually the largest thing on a page. Format and compression choices routinely cut that weight in half with no visible difference.
next/image solves format, sizing and lazy loading for you — and then hands you two props, sizes and priority, that decide whether your LCP is 1.2s or 4s.
A div can be styled to look like anything. It cannot be understood as anything, which is the whole problem.
No spam. Just the occasional case study and craft breakdown.