Alt text for AI-generated images should be clear, useful, and honest. It should describe what the image shows and why it matters in context. It should not stuff keywords or describe the generation tool.
Good alt text helps accessibility and supports image SEO because it gives search systems a natural description of the image.
A Simple Formula
Use this formula:
[Image type] of [main subject] showing [relevant context or action].
Examples:
Illustration of a content editor planning image slots for a blog article.
Diagram showing a four-step workflow from article analysis to image generation.
Alt Text Examples by Image Type
| Image type | Weak alt text | Better alt text |
|---|---|---|
| Hero image | AI blog image | Illustration of a writer turning a blog draft into a visual content plan |
| Process image | workflow | Diagram showing article analysis, image slot planning, prompt review, and image generation |
| Comparison image | comparison graphic | Side-by-side illustration comparing a featured image with an in-article explainer |
| Technical image | architecture | Abstract diagram of article input moving through a planning engine into image slots |
| Checklist image | SEO checklist | Illustration of a publisher reviewing filename, alt text, caption, and image placement |
What to Avoid
Avoid alt text that is:
- Keyword stuffed
- Too vague
- Too long
- Focused on irrelevant visual details
- Misleading about what the image shows
Weak:
Best AI blog image generator image SEO tool for article illustrations.
Better:
Illustration of a blog post with planned image slots beside key sections.
Example Illustration Plan
| Article section | Image purpose | Suggested prompt | Suggested size |
|---|---|---|---|
| Alt text formula | Explain rule | Clean visual showing an image preview connected to a concise alt text field, modern accessibility-focused blog illustration | 4:3 |
| Mistakes section | Contrast examples | Side-by-side visual of vague alt text versus useful alt text represented as simple UI cards, no readable text | 4:3 |
| Publishing checklist | Show process | Content editor reviewing generated image, caption, filename, and alt text before publishing, polished SaaS style | 16:9 |
Write Alt Text After Reviewing the Image
Do not write final alt text from the prompt alone. Generated images can differ from the prompt. Review the final image first, then describe what is actually visible.
This is especially important for AI-generated images because details can shift. If your prompt asked for a content editor but the final image shows a team dashboard, the alt text should describe the dashboard, not the original prompt.
Connect Alt Text to Nearby Content
The same image might need slightly different alt text depending on placement. If the image supports a section about prompt planning, describe the planning. If it supports a section about SEO, describe the publishing context.
For broader publishing guidance, read Image SEO for AI-Generated Blog Images.
AI Article Illustrator can help by keeping each image tied to a specific article section, which makes alt text easier to write.
How Long Should Alt Text Be?
There is no magic character count. A useful range for blog illustrations is often one concise sentence. If you need two sentences to describe a complex diagram, the image may be too complex or may need a caption.
Good:
Illustration of a marketing team reviewing planned image slots before generating blog visuals.
Too long:
An extremely detailed illustration of several people sitting at a table with laptops and papers and screens and a calendar and a content plan and many image thumbnails representing different parts of a blog workflow.
Alt Text vs Caption
Alt text describes the image for accessibility. A caption explains why the image matters in the article.
Alt text:
Diagram showing a four-step workflow from article draft to generated images.
Caption:
Planning image slots before generation helps each visual support a specific section.
Use both when the image is important and benefits from interpretation.
FAQ
Should alt text mention that the image is AI-generated?
Usually no. Alt text should describe the image. If your editorial policy requires AI disclosure, put it in a caption, note, or image credit instead.
Should I include keywords in alt text?
Only if they naturally describe the image. Keyword stuffing makes alt text worse for users and does not make the image more helpful.
Can I reuse the prompt as alt text?
No. A prompt gives creation instructions. Alt text describes the final image. They are related, but not the same.
Alt Text Review Checklist
Before publishing, check:
- Does the alt text describe the final image?
- Is it useful without seeing the image?
- Does it avoid keyword stuffing?
- Does it match the nearby section?
- Is it shorter than a caption?
- Does the caption carry interpretation if needed?
If the alt text sounds like a prompt, rewrite it. If it sounds like a keyword list, rewrite it. If it describes something that is not visible in the final image, rewrite it.
Example Workflow
- Generate the image from the approved prompt.
- Review the final visual.
- Write one descriptive sentence.
- Add a caption only if the article needs interpretation.
- Keep filename, alt text, and caption aligned with the section.
This is easier when the image began as a planned slot. The section already tells you what the image is supposed to support.