Free Alt Text Generator
Paste an image URL and get AI-generated, SEO-optimized alt text in seconds. Up to 3 free generations per day — no account needed.
3 of 3 free generations remaining today
What Is Alt Text and Why Does It Matter?
Alt text — short for alternative text — is a written description added to the alt attribute of an HTML <img> tag. It serves three critical purposes: it makes images accessible to visually impaired users who rely on screen readers, it gives search engines context about your visual content, and it provides a text fallback when images fail to load.
Without alt text, screen readers announce images as "image" or read the filename — often something unhelpful like "IMG_4582.jpg." For the 2.2 billion people worldwide with vision impairments, missing alt text means missing content.
From an SEO perspective, Google has confirmed that alt text is one of the strongest signals for image search ranking. Pages with descriptive alt text on images tend to rank better for related queries because the alt text reinforces the page's topical relevance. Between 20-36% of all Google searches happen on Google Images — a channel you lose entirely without proper alt text.
Why Use an AI Alt Text Generator?
Better SEO Rankings
Descriptive alt text helps search engines index your images and boosts your page's topical relevance for target keywords.
WCAG Compliance
Meet WCAG 2.1 Level AA requirements and reduce legal risk from ADA accessibility lawsuits, which have risen 300% since 2018.
Save Hours of Work
Writing alt text manually takes 30-60 seconds per image. AI generates quality descriptions in under 2 seconds each.
How to Write Good Alt Text: Best Practices
Whether you write alt text manually or use AI, following best practices ensures your descriptions serve both users and search engines effectively.
- Be specific and descriptive — describe what the image shows, not what you want it to mean
- Keep it concise — aim for 80-125 characters. Screen readers can handle longer text, but brevity improves the listening experience
- Include relevant keywords naturally — don't stuff keywords, but do mention them when they accurately describe the image
- Don't start with "image of" or "picture of" — screen readers already announce that it's an image
- Describe the function, not just appearance — if an image is a button or link, describe what it does
- Use empty alt="" for decorative images — backgrounds, spacers, and ornamental graphics should have null alt text
- Consider context — the same image may need different alt text on a product page vs. a blog post
How This Free Tool Works
Paste Image URL
Enter the public URL of any image you want to generate alt text for.
AI Analyzes the Image
Our GPT-4.1-nano model examines the visual content, objects, text, and context.
Get Your Alt Text
Copy your SEO-optimized, accessible alt text and add it to your HTML.
Need More Than 3 Images? Scale With AltFrame
This free tool is perfect for quick, one-off alt text generation. But if you manage a website with hundreds or thousands of images, you need a scalable solution. AltFrame offers:
- Bulk processing — upload CSV files with image URLs and get alt text for all of them
- REST API — integrate alt text generation directly into your CMS, CI/CD pipeline, or custom workflow
- Multiple output fields — get alt text, SEO titles, captions, and Open Graph descriptions in one call
- E-commerce mode — include product names, SKUs, and attributes for catalog-optimized descriptions
- Multi-language support — generate alt text in 20+ languages
Frequently Asked Questions
What is alt text?
Alt text (alternative text) is an HTML attribute added to image tags that describes the content and function of an image. It is read by screen readers, displayed when images fail to load, and used by search engines to understand image content.
Why is alt text important for SEO?
Search engines cannot see images directly. Alt text helps Google and other search engines understand what an image depicts, improving your chances of ranking in image search results and boosting the topical relevance of your pages.
How does the free alt text generator work?
Paste an image URL and our AI analyzes the visual content using GPT-4.1-nano to generate a concise, descriptive alt text. The result is optimized for both accessibility and search engines.
Is there a limit on free usage?
Yes — you can generate alt text for up to 3 images per day without signing up. For unlimited access, bulk processing, and additional fields like titles and captions, create a free AltFrame account.
Does AI-generated alt text meet WCAG requirements?
Our AI generates descriptive, concise alt text following WCAG 2.1 guidelines. For compliance-critical sites, we recommend a quick human review of generated text, which AltFrame makes easy with its editing workflow.
Can I use this for e-commerce product images?
Absolutely. AltFrame supports an e-commerce mode that includes product names, SKUs, and attributes in the generated alt text — ideal for product catalogs with hundreds of images.