Image Alt Text in WordPress: Accessibility, SEO and Practical Coverage

An image in WordPress without alt is an image only sighted users can understand. A screen reader announces "image" or the file name instead of describing the content; a search engine cannot tell what the picture is about; and on a slow connection where the image fails to load, the visitor sees an empty box instead of a hint.

Why this matters

This is the very first international accessibility guidelines Level A requirement - 1.1.1 Non-text Content. Popular screen readers (NVDA on Windows, JAWS, VoiceOver on macOS/iOS, TalkBack on Android) use alt to describe the image to a blind user: "Chart showing a 23% sales increase in Q2." Without alt the user just hears "image" and stalls.

Beyond accessibility, alt directly affects SEO. Google Images indexes images mostly by alt, file name and surrounding text. An image with descriptive alt appears in image searches; without it, it does not. alt also serves as a fallback when the image fails to load (ad blocker, slow link, CSP blocking the CDN) - the visitor at least understands what should have been there. Legally, accessibility for service-providing sites is required in most jurisdictions and missing alt is a primary audit finding.

How to detect

Run the Missing Alt Text Scanner built into RankPlus - it walks posts, postmeta and options and lists images without alt. External tools: WAVE by WebAIM, axe DevTools by Deque (Chrome/Firefox extension), Lighthouse in Chrome's Accessibility tab. All flag the same problems. Manually: view source, search for <img and confirm each tag has alt="...".

How to fix

1. Open the Media Library > pick an image > Edit > fill Alternative Text.
2. Write a short, accurate description. For a product photo - name and a salient feature ("Black office chair with adjustable lumbar support"). For an infographic - the headline finding ("Revenue grew 40% from 2023 to 2024"). For an atmosphere shot - the context ("Team in a planning meeting").
3. For purely decorative images (separator lines, icons next to text) - use alt="". An explicit empty value tells screen readers to skip. Do not just leave the attribute off entirely - that is not the same.
4. In the Gutenberg block editor - select the image and fill the right-hand "Alt text (alternative text)" panel. The value is stored on the attachment and on the block.
5. For images inside Galleries or Cover blocks - check each one individually. People often forget gallery images.
6. If you have hundreds or thousands of images, use the RankPlus AI Alt Generation to draft text in bulk. Review and edit afterwards - AI cannot know your business context.
7. Re-run the scan - aim for 95%+ coverage. 100% is rare because some images are not detected by automated walks.

Common mistakes

• Echoing the filename: alt="IMG_4587.jpg" is not a description. Worse than empty alt.
• SEO stuffing: alt="cheap repair service price low fast". Google detects spam and ranks down.
• Using alt as a tooltip: that is what title is for. alt targets screen readers and fallback.
• Over-long descriptions: "Photo of a smiling woman in a white shirt with a green background, standing by a wooden desk" - non-sighted users do not need that. "Customer service representative" is enough.
• Letting wp-admin default to "image": an unaware editor accepts the suggestion. Override every time.

Verifying the fix

Re-run the RankPlus scan. In WAVE the "Missing alternative text" error count should be zero. Open a page in NVDA or VoiceOver and move through the images - you should hear the descriptions you wrote, not "image".