Image Alt Text & Image SEO Checker
Scan any webpage for missing alt attributes, empty alt text & oversized images. Get format and optimization tips to boost image SEO, free.
How to Use Image Alt Text & Image SEO Checker
Choose URL Input to scan a live webpage, or Paste Raw HTML to check a draft before publishing.
Click 'Check Image Alt Tags' to run the scan. Images are often the most neglected part of an SEO audit. Missing or empty alt text can sit unnoticed for years, even though alt text is a direct WCAG accessibility requirement and a key Google Images ranking factor.
Review the flagged list — missing alt attributes, empty alt text, oversized files, and format recommendations.
Fix each image's alt attribute and convert oversized graphics to modern formats (WebP/AVIF) before publishing.
Why It Matters
- ✓Alt text is a WCAG accessibility requirement, not an optional SEO extra — missing alt text is a compliance issue as much as a ranking one.
- ✓Google Images is a meaningful traffic source for product, recipe, and visual-heavy content, and it relies almost entirely on alt text and file context.
- ✓Oversized, unoptimized images are one of the most common causes of poor LCP scores in Core Web Vitals audits.
- ✓Modern formats (WebP, AVIF) can cut file size significantly over legacy JPG/PNG with no visible quality loss.
Key Features
- •Full-page image scan with preview cards
- •Missing and empty alt detection
- •Decorative vs. informative image classification
- •File size and modern format (WebP/AVIF) recommendations
- •Works on live URLs or raw HTML with no sign-up
Frequently Asked Questions
Everything you need to know about Image Alt Text & Image SEO Checker
Should every image on a page have alt text?
Purely decorative images (spacers, background flourishes) can intentionally use an empty alt="" attribute, which tells screen readers to skip them. Every informative image, though, needs descriptive alt text.
What makes alt text 'good' versus just present?
Good alt text describes what's actually in the image in plain language, specific enough to be useful to someone who can't see it — 'orange tabby cat sleeping on a windowsill' rather than just 'cat' or a stuffed keyword phrase.
Does alt text help rankings for the page itself, or just for Google Images?
Both, to different degrees. It's a strong direct signal for Image Search rankings, and a smaller but real contextual signal for the page's overall topical relevance in regular search.
How much does image file size actually affect page speed?
Significantly. Unoptimized images are consistently one of the top causes of poor Largest Contentful Paint scores, especially on mobile connections, since large files delay when the main visible content finishes loading.
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