Free AI alt text generator

What is alt text?

Alt text is the written description of an image that lives in your page's HTML, in the alt attribute. Screen readers speak it aloud to blind and partially sighted visitors. Google uses it to understand what a picture shows for image search. An image without it is silent to both.

For content images, alt text is required by WCAG 2.2 Success Criterion 1.1.1.

What makes alt text good

• It says what the image shows, concretely. "Olive-green waterproof hiking boots laced on a grey rock" beats "boots".
• It fits the page around it. The same photograph needs different text on a product page and in a news story.
• It is the right length: one sentence. Many practitioners aim for under 125 characters, and our score treats anything over 250 as too long to follow by ear.
• It skips the preamble. Screen readers already announce an image, so "image of" and "picture of" waste the listener's time.
• It is empty on purely decorative images. An empty alt attribute correctly tells screen readers to stay silent.

Before and after

alt="IMG_4032.jpg" · a filename tells the listener nothing

alt="image" · junk: the screen reader says "image, image" twice

alt="A waiter carries two seafood platters across a candlelit dining room" · concrete, in context, one sentence

How this generator works

Your image goes to NarraSight's server and a vision model describes only what is visible. NarraSight does not keep your image. It is sent to our AI model provider to be described, under terms that bar training on it. The generator sees the image alone, so it writes the best context-free description it can. The full NarraSight product goes further: it reads each image in the context of the page it sits on and your brand vocabulary, holds anything uncertain for a person to review, and writes the approved text into WordPress, Shopify or your own platform, with an audit trail.

Common questions

What is alt text?

Alt text is the written description of an image that lives in your page's HTML. Screen readers speak it aloud to blind and partially sighted visitors. Google uses it to understand what a picture shows for image search. An image without it is silent to both. It is required for content images by WCAG 2.2 Success Criterion 1.1.1.

How long should alt text be?

One concrete sentence is usually right. Many practitioners aim for under 125 characters, and our score treats anything over 250 as too long to follow by ear. If an image needs more than that, put the detail in the surrounding copy or a long description and keep the alt text focused.

Does every image need alt text?

Every content image does. Purely decorative images should instead carry an empty alt attribute, which correctly tells screen readers to stay silent. What fails is the middle ground: content images with no alt attribute, or with junk such as a filename or the word image.

Does alt text help SEO?

Google's image guidance calls alt text the most important attribute for giving it information about an image, and uses it to understand what the picture shows for image search. The gains come from accurate, in-context descriptions, not from keyword stuffing, which the same guidance warns against.

Is this generator free, and is my image stored?

Yes, it is free, with a fair-use limit of a few images per minute. Your image is sent to NarraSight's server and described. NarraSight does not keep it. It is sent to our AI model provider to be described, under terms that bar training on it.

What is the difference between this and the full NarraSight product?

This page describes one image at a time from the image alone. The full product reads each image in the context of the page around it and your brand vocabulary, holds anything uncertain for human review, writes approved text into WordPress, Shopify or your own platform, and keeps an audit trail.