Image SEO Checklist

What is Image SEO Checklist?

Image SEO Checklist provides an audit framework for optimizing images for search engine visibility, covering alt text quality, filename descriptiveness, file format selection, compression, responsive sizing, lazy loading, structured data markup, and Open Graph image tags. It evaluates each optimization factor and produces a scored report with specific recommendations. The tool also checks that images meet Core Web Vitals thresholds for Largest Contentful Paint (LCP) and Cumulative Layout Shift (CLS).

SEO specialists optimizing image search traffic, performance engineers improving Core Web Vitals scores, and content managers building image upload guidelines. The tool runs entirely in your browser — your data never leaves your device.

How to Use Image SEO Checklist

1. Enter the URL of a page to audit or upload your image assets for review
2. Review each checklist item — alt text, filename, format, size, dimensions, lazy loading
3. See the score for each category and overall image SEO health rating
4. Follow the specific recommendations for each failing item to improve your score

Common Use Cases

• Auditing website images for search engine optimization before a site launch
• Creating image optimization workflows for content teams uploading to a CMS
• Improving page speed scores by identifying unoptimized images that affect Core Web Vitals
• Training content creators on image SEO best practices with a structured checklist

Pro Tips

• WebP format is 25-35% smaller than JPEG at equivalent quality — use it as the primary format with JPEG fallback via the <picture> element for the ~4% of users on older browsers
• The LCP element is often a hero image — if your LCP image is lazy-loaded, it waits until JavaScript runs to start downloading; add fetchpriority='high' and remove loading='lazy' from above-the-fold images
• Always include explicit width and height attributes on img tags — they allow the browser to reserve space before download, preventing CLS (layout shift) when the image loads

Why Use This Tool?

• Privacy-first: All processing happens locally in your browser. No data is transmitted to any server.
• No installation required: Works in any modern browser on desktop or mobile.
• Completely free: No account, no credit card, no usage caps.
• Fast and reliable: Powered by modern Web APIs for near-instant results.

Related Concepts

Learn more about related topics: Core Web Vitals, Image compression, WebP format, Lazy loading.

Frequently Asked Questions