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How to Optimize Images for SEO

Images are a critical part of SEO. Google considers page speed as a ranking factor, and images are often the heaviest elements on a page. Here's how to optimize them.

Why Image Optimization Matters for SEO

Google's Core Web Vitals include Largest Contentful Paint (LCP), which often involves a hero image. Slow-loading images directly hurt your rankings. Optimized images also appear in Google Image Search, driving additional organic traffic.

1. Compress Your Images

This is the single most impactful optimization. Use tools like Compresso to reduce file sizes by 50-80% without visible quality loss. Aim for images under 200KB for most web use cases.

2. Use Descriptive File Names

Instead of IMG_4532.jpg, use chocolate-cake-recipe.jpg. Search engines use file names as ranking signals for image search.

3. Write Meaningful Alt Text

Alt text helps search engines understand image content. Be descriptive but concise: "A slice of chocolate cake on a white plate" is better than "cake" or "image1".

4. Choose the Right Dimensions

Don't serve a 3000px image in a 600px container. Resize images to their display dimensions. Use srcset for responsive serving.

5. Use Modern Formats

Convert to WebP for 25-35% smaller files compared to JPEG. Use the <picture> element to serve WebP with JPG fallbacks.

6. Implement Lazy Loading

Add loading="lazy" to below-the-fold images. This improves LCP by prioritizing above-the-fold content.

7. Add Structured Data

Use schema markup for product images, recipes, and articles. This helps Google understand context and can earn rich snippets.

8. Create an Image Sitemap

Include images in your XML sitemap or create a dedicated image sitemap. This helps Google discover and index your images faster.

9. Use a CDN

Serve images from a CDN to reduce latency. Many CDNs offer automatic format conversion and resize-on-the-fly features.

10. Monitor Performance

Use Google PageSpeed Insights and Lighthouse to identify unoptimized images. Set up monitoring to catch regressions.


Start optimizing your images today with Compresso — free, fast, and completely private.