How to write alt text with AI Image Describer

Image descriptions do a lot of heavy lifting. They help visually impaired visitors understand what is on the screen, they give search engines context about your page, and they boost conversions by clarifying the action that a user should take. In this guide we walk through an imagetotext.io–style process using AI Image Describer—the GPT-4o Vision workflow built for SaaS marketers, ecommerce stores, and creative agencies.

Why alt text matters

• Accessibility: screen readers rely on alt attributes to narrate page layouts. Leaving them blank creates a poor experience for thousands of users.
• SEO: keywords sprinkled naturally in alt text help Google Images, Pinterest, and discovery feeds understand what the asset represents.
• Compliance: regulations such as WCAG 2.1, ADA, and Section 508 expect authors to describe imagery. Automating the process lowers legal risk.

Generate copy in four steps

1. Upload – drag or select your product photo, UI screenshot, or infographic. We support JPG, PNG, GIF, JFIF, and PDF.
2. Check the preview – confirm the thumbnail and file name before generating copy.
3. Click “Generate description.” The browser converts the file to base64, we send it to GPT‑4o Vision, and you get three fields: a long description, alt text, and caption. Each copy block follows best practices and stays under 120 characters where appropriate.
4. Copy or tweak. Use the Copy buttons to paste into your CMS or edit before saving. Signed-in users can revisit recent runs in the dashboard usage log; CSV export is on the roadmap.

Best practices

| Scenario | Recommendation | | --- | --- | | Product shot | Mention the item, angle, color, and purpose | | UI screenshot | Describe the layout, key widgets, and CTA labels | | Lifestyle image | Highlight the subject, mood, and action | | Promo graphic | Explain the offer, deadline, and supporting icons |

Keep actual alt attributes between 90–120 characters and push longer context into the long-description field. Avoid keyword stuffing—mention the target keyword once naturally.

Example output

• Image: sustainable running shoes on a wooden floor with morning sunlight.
• Alt text: “Pair of sustainable running shoes next to a reusable bottle under morning light.”
• Long description: details the recycled mesh fabric, the warm sunlight, and the positioning near the window.
• Caption: “Lace up eco-friendly runners built for daily commutes.”

When to regenerate

• You updated a colorway, UI layout, or hero banner.
• You translated the page into another language.
• You want to A/B test alt text for SEO or accessibility audits.

With AI Image Describer, alt text creation is no longer the tedious chore it used to be. Drop any visual into the converter, receive production-ready language, and keep your entire site WCAG compliant—without leaving the browser.