Free tool
Image alt text checker
Paste a public page URL to find images with missing alt attributes, empty alt text, generic values, duplicates, or long descriptions. Scanning is free and doesn't need an account. The checker reads the initial HTML of one page and checks up to 250 images, so images that JavaScript adds after the page loads won't show up.
Good for
- Find missing alt attributes before publishing.
- Separate empty decorative attributes from real accessibility gaps.
- Spot repeated product image alt text.
- Draft replacement alt text for a few flagged images.
What the checker looks for
- Images with no alt attribute, which many audits report as missing alt attributes.
- Images with an empty alt attribute, including cases where alt="" may be intentional.
- Generic values like image, photo, graphic, or screenshot.
- Duplicate alt text reused across multiple images on the same page.
- Long descriptions that are hard to review in a CMS field.
How I would use the results
- Fix meaningful content images first; decorative images may intentionally use empty alt text.
- Treat scanner results as a review queue, not an instruction to fill every decorative image.
- AI replacement drafts are optional and capped: 3 without an account, then 2 more with a free account, counted across AltCaption's generators.
- Review each draft against the actual page context before publishing.
- The checker doesn't render the page in a browser or confirm accessibility compliance. For pages that load images with JavaScript, run Lighthouse or axe DevTools on the rendered page.
Example audit
A product collection page with 42 images might show 8 missing alt attributes, 4 repeated product names, and 2 generic values. Start with the missing product photos, then clean up duplicates where variant details matter.
Fix missing alt attribute audit errorsRelated free alt text tools
Bulk image alt text generator
Paste a short list of hosted image URLs to preview generated alt text, then use AltCaption Pro for larger batches, TSV export, and account history.
Product image alt text generator
Generate product image alt text with product name, category, and visible details as publishing context.
Bulk edit Shopify image alt text from a product CSV
Bulk edit missing Shopify product image alt text from a CSV. Audit blank rows, generate review-ready drafts, and download a preserved import file.
Alt attribute generator
Generate concise image alt text, escape it safely, and copy a ready-to-use HTML alt attribute for CMS, static-site, or code updates.
Image alt text validator
Check image alt text for empty, generic, overly long, or keyword-stuffed wording, then generate a replacement draft from an image URL.
Social image alt text generator
Generate concise alt text drafts for Instagram, Pinterest, Bluesky, X, and other social images using platform, topic, and visible-text context.