Alt Text Writing Guide: Improve Accessibility & SEO

In today’s visual-first digital world, images are one of the most powerful elements of any webpage, but only if every user can understand them. That’s why an Alt Text Writing Guide is essential. Well-written alt text bridges the gap for people who rely on screen readers, ensures your website meets modern accessibility standards—including ADA and EAA compliance—and gives search engines the context they need to index your images accurately. Done right, alt text strengthens both user experience and SEO performance, helping your site rank higher, load smarter, and reach a wider audience.

1. What Is Alt Text?

Alt text, or alternative text, is a brief, descriptive label added to images on a webpage that explains their content and purpose. It ensures accessibility by allowing screen readers to convey visual information to users with visual impairments, while also helping search engines understand and index images for better SEO. Well-crafted alt text provides context, enhances user experience, and increases the chances of your images appearing in relevant search results, effectively bridging the gap between visual content, accessibility, and search visibility.

2. How to Write Effective Alt Text

• Be Descriptive and Meaningful: Focus on the purpose and content of the image rather than every tiny detail. Describe what matters most to someone who cannot see it.

• Keep It Relevant to the Page Context: Ensure your alt text reflects why the image is on the page. Include details that matter to the content topic.

• Use Keywords Naturally: Including keywords can enhance SEO, but avoid stuffing them. Keywords should appear naturally and only if they fit the image’s purpose.

• Keep It Concise: Alt text should be short and clear, ideally under 125 characters, so screen readers can read it smoothly.

• Decorative Images Appropriately: If an image is purely decorative and does not add meaning, use an empty alt attribute (alt=””). This allows screen readers to skip it.

• Use Unique Descriptions: Avoid generic phrases like “image of a puppy ” for multiple images. Tailor each description to the specific image, highlighting unique details.

• Test and Revise Regularly: Review your alt text with screen readers to ensure it conveys the intended meaning. Update alt text if the context changes or if the description can be improved.

Following these alt text best practices strengthens both accessibility and SEO. Clear, meaningful image descriptions help create an inclusive user experience while giving search engines the context they need to rank your pages higher.

For teams handling hundreds or thousands of images, writing alt text manually can be overwhelming. With Autoalt.ai’s bulk generation tool, you can apply accurate, high-quality alt text at scale—ensuring every image meets accessibility and SEO standards without the manual workload.

Scenario: A woman shopping for clothes in a mall

Bad Alt Text:

“image1.jpg”

Why it’s bad: This doesn’t describe the image — it’s just the file name.

Okay Alt Text:

“woman shopping for clothes in a mall”

Why it’s okay: It gives a general idea of the image, but it lacks important details and context. It works, but it isn’t very helpful for users.

A Good Alt Text Example

“A woman with long brown hair browses clothes on a rack in a brightly lit store, reaching up to look at a light-colored garment.”

Why it’s good: It clearly describes the image and helps someone who can’t see it imagine the scene. It includes simple details about the place, mood, and objects, making the picture easy to understand.

Scenario: A woman sits at a desk typing on a computer keyboard in an office.

Bad Alt Text:

“Woman.jpg”

Why it’s bad: It gives no helpful information. Screen readers and search engines can’t understand the image from this text.

Okay Alt Text:

“A woman sits at a desk typing on a computer.”

Why it’s okay: It gives a basic idea of what the image shows, but it’s still missing helpful details that make the description truly useful.

A Good Alt Text Example

A woman with long brown hair sits at a desk, typing on a computer keyboard in a bright, modern office space.

Why it’s great: It clearly explains the key insights, so even someone who can’t see the chart understands the trend.

Alt Text Writing Checklist

Use this practical checklist to make every image on your site accessible, descriptive, and SEO-friendly.

• Is it descriptive and clear
• Is it relevant to the page context
• Is it under ~125 characters (when possible)
• Does it describe the purpose or information
• Are decorative images marked correctly
• Is the keyword used naturally (if relevant)
• Is every image unique and meaningful

Curious how professional alt text is created? Use our interactive Alt Text Generator with your images and let AI generate accurate, best-practice descriptions automatically.