For transactional email
Consider SMTP2GO for website-generated messages, form notifications, account notices, and other outbound system email.
Explore SMTP2GOAvailableFree browser-local analysis
Image Optimization Checker
SiteTend Image Optimization
Find accessibility gaps, layout-shift risks, delayed loading opportunities, and non-responsive image markup before publishing.
Your input stays private.HTML is analyzed in your browser.
Paste image markup
Add complete HTML, img elements, or image-related fragments.
Review image markup
Start with accessibility and layout-stability issues.
Your analysis will appear here
Paste markup and select Analyze images.
How to improve
Match each image to its purpose and layout
Describe informative images, hide decorative images correctly, reserve layout space, provide responsive candidates, and defer offscreen work. Confirm every heuristic with real rendered dimensions and transfer measurements.
Questions
Image Optimization Checker FAQ
What does the Image Optimization Checker analyze?
It reviews alt attributes, intrinsic dimensions, lazy loading, async decoding, responsive source markup, duplicates, declared size, and image format hints.
Should every image have descriptive alt text?
No. Informative images need contextual alternative text, while intentionally decorative images should normally use an empty alt attribute.
Should the first image use lazy loading?
Not automatically. A prominent image may be the Largest Contentful Paint element and should usually be discovered eagerly. This checker evaluates later images as likely lazy-loading candidates.
Can this checker measure image file size?
No. Version 1 analyzes pasted markup only and cannot fetch files, measure compression, or determine rendered dimensions.
Apply the result
From finding to verified fix
Interpret the finding
Prioritize images that are large, above the fold, or missing dimensions. Not every modern-format or lazy-loading suggestion applies to every image.
Common causes to inspect
- Original assets served at display size
- Missing responsive candidates
- Dimensions or loading priority omitted by templates
Practical next steps
- Match delivered dimensions to display needs
- Add explicit dimensions and responsive sources
- Retest visual quality and loading performance
What this check cannot prove
Pasted markup cannot measure transferred bytes, decoded dimensions, visual quality, caching, or the final layout.
Recommended resources
Useful next steps for operating a website
For measuring business inquiries
Use WhatConverts to measure which marketing sources produce calls, forms, and leads. It measures outcomes; it does not fix technical website issues.
Explore WhatConvertsFor personal-data privacy
Consider Optery if exposed personal information or data-broker listings are a concern. It is a separate privacy resource, not an SEO or website-security scanner.
Explore OpterySiteTend may earn a commission if you purchase through these links, at no additional cost to you. These services are optional and separate from SiteTend's free checks.