Image Gallery Accessibility Checker

Image galleries are a core component of e-commerce, photography, real estate, portfolio, and media websites. For screen reader users, an image gallery without alt text is a sequence of meaningless "image" announcements. For keyboard users, a gallery without proper navigation is a maze of unlabeled thumbnails.

Missing alt text is the most common WCAG violation on the web, found on over 55% of home pages according to the WebAIM Million analysis. For galleries with dozens or hundreds of images, the impact is multiplied. With the European Accessibility Act covering e-commerce and the ADA Title II deadline of April 24, 2026 approaching, image-heavy websites face particular scrutiny.

Image galleries combine thumbnails, lightboxes, navigation controls, and often lazy loading — each with accessibility requirements. CompliScan detects these patterns:

• Missing or generic alt text — images with empty alt="" (treated as decorative), alt="image", or alt="IMG_4523.jpg" provide no useful information to screen reader users.
• Lightbox overlays without focus management — clicking a thumbnail opens a lightbox, but focus doesn't move to the lightbox content, and keyboard users can tab to elements behind the overlay.
• Gallery navigation without keyboard support — previous/next arrows that respond only to mouse clicks, with no keyboard alternatives for cycling through images.
• Lazy-loaded images without alt text — JavaScript lazy loading that replaces placeholder elements with images sometimes drops alt text during the swap, or uses a generic placeholder alt until the real image loads.

Run a free CompliScan scan on pages containing image galleries. The scanner evaluates alt text presence, lightbox structure, and navigation element accessibility.

For alt text, every content image needs a descriptive alternative: "Sunset over Tallinn Old Town, view from Toompea Hill" not "sunset.jpg." For purely decorative images, use alt="" with role="presentation". For lightboxes, implement focus trapping: when the lightbox opens, move focus to the lightbox container, trap Tab within the lightbox (close button, navigation, image), and return focus to the triggering thumbnail when closed. Use role="dialog" and aria-modal="true".

For navigation, ensure previous/next buttons work with Enter/Space and arrow keys. Add aria-label="Previous image" and aria-label="Next image" to icon-only buttons. CompliScan's Shield plan ($49/mo) monitors galleries with weekly scans, catching issues when new images are added without alt text.

WCAG 2.1 AA addresses images through several criteria: 1.1.1 Non-text Content (alt text for all content images), 1.4.5 Images of Text (avoid text in images), 1.3.1 Info and Relationships (image lists and grouping), and 4.1.2 Name, Role, Value (interactive image controls need accessible names).

For lightbox overlays, 2.4.3 Focus Order and 2.4.7 Focus Visible apply. The ADA Title II April 2026 deadline and European Accessibility Act make these requirements legally binding.

Automated tools like CompliScan catch approximately 30-40% of WCAG issues related to images, including missing alt attributes, empty alt on non-decorative images, and lightbox ARIA problems. Alt text quality (whether descriptions are accurate and useful) requires manual review.