What is alt text and why does it matter for SEO?

Alt text describes an image for search engine crawlers (who cannot see images) and screen readers. Good alt text helps images rank in Google Image Search and improves accessibility.

Should I compress images before uploading to my website?

Always — uncompressed images are a major cause of slow page speeds, which hurts both user experience and Google rankings. Target under 200KB for hero images and under 50KB for thumbnails.

What format should website images be in?

WebP is the best format for website images in 2026 — 25-35% smaller than JPEG with similar quality, supported by all modern browsers. Use JPEG as a fallback for older browsers.

Image SEO: How to Optimise Images for Google Search

Why Image SEO Matters

Google Images is the world's second largest search engine after Google itself. For e-commerce, food, travel, fashion, and visual industries, image search drives significant traffic. Even for non-visual websites, poorly optimised images hurt Core Web Vitals and page SEO.

Alt Text: The Most Important Image SEO Factor

Alt text (alternative text) describes an image for:

Screen readers used by visually impaired users
Google's crawlers that cannot see images
Display when images fail to load

Good alt text: Describes the image specifically and includes relevant keywords naturally.

Bad alt text: "image1", "photo", or keyword stuffing ("buy cheap running shoes best running shoes discount running shoes").

Examples:

Product image: alt="Red Banarasi silk saree with gold zari border"

Blog image: alt="Mumbai skyline at sunset from Marine Drive"

Tool screenshot: alt="PDF compression tool interface showing before and after file sizes"

File Names

Name image files descriptively before uploading. Google reads file names.

Bad: IMG_20260115_094523.jpg

Good: mumbai-skyline-marine-drive-sunset.jpg

Use hyphens to separate words. Use lowercase. Keep it descriptive and concise.

Image Compression for Page Speed

Unoptimised images are the #1 cause of slow page loads. Google's Core Web Vitals (LCP — Largest Contentful Paint) is heavily influenced by image loading.

Compress before uploading: Use Lazyblink Compress Image to reduce file size before adding to your website. Target under 200KB for hero images, under 50KB for thumbnails.

Use WebP format: 25-35% smaller than JPEG at equal quality. Supported by all modern browsers. WordPress automatically serves WebP to compatible browsers.

Lazy loading: Add loading="lazy" to image tags below the fold. Defers image loading until the user scrolls near them.

Structured Data for Images

For product images: Add Product schema markup including image URLs.

For recipe images: Recipe schema with high-quality images increases appearance in Google Recipe results.

For news articles: Article schema with representative images helps appear in Google News with image.

Image Sitemap

Include images in your XML sitemap or create a separate image sitemap. This helps Google discover and index images that might not be found through crawling alone.

In WordPress, Yoast SEO automatically includes images in the sitemap.