Create alt text for website images
A practical way to use AI for this job in a small business, with a prompt you can copy.
Your website has 200 images and the alt text field is empty on all of them. You've heard it matters for accessibility and SEO, but who has time to write 200 descriptions?
The prompt
Write alt text for this image for my website page about [topic]. Describe what's actually in the image in under 125 characters. Don't start with 'image of'.
Replace everything in [square brackets] with your own details. Don't paste in anything you wouldn't want stored by the AI provider.
Steps
- Upload the image to your AI tool.
- Run the prompt.
- Check it describes what's really there.
- Paste it into the alt text field in your website editor.
A worked example
A Melbourne florist uploads 10 product photos to ChatGPT at once and asks for alt text under 125 characters for each, describing what's actually in the photo. She gets lines like 'Bouquet of white roses and eucalyptus wrapped in brown paper'. She tweaks a few to include the product name and pastes them into Shopify.
Batches of 10 take about 10 minutes, including checks. The whole site gets done over a week of short sessions.
Where it goes wrong
AI sometimes guesses wrong about what's in a photo, like calling a eucalyptus sprig 'olive leaves' or a kelpie a 'border collie'. Read every line before you paste it in. Also watch for keyword stuffing: alt text that says 'best florist Melbourne cheap flowers' helps nobody and reads badly to screen reader users.
Time saved
Writing alt text by hand is about 2 to 5 minutes an image. With AI in batches, it drops to under a minute each. These are my estimates for a typical small business, not measured results.
What it costs (AUD)
Image uploads have tighter limits on free plans. For a big site, one month of a paid plan might be worth it.
The free plans of ChatGPT, Claude and Gemini handle this fine. If you end up using AI every day, the paid plans are roughly: ChatGPT Plus approx. A$30 a month, Claude Pro approx. A$29 a month billed monthly (US$20, or about A$24 a month if you pay yearly), and Google AI Pro approx. A$33 a month through the App Store. Prices approx., October 2026. Some are billed in US dollars, so your bank may add a foreign transaction fee. Check the vendor's pricing page before you buy.
Australian notes
Accessibility matters here: Australia's Disability Discrimination Act applies to websites, and the Web Content Accessibility Guidelines (WCAG) are the usual benchmark. Alt text is one of the easiest wins. Avoid naming people in photos unless you have their permission.
Privacy: the Privacy Act and the Australian Privacy Principles (APPs) cover most businesses turning over more than $3 million, plus some smaller ones such as health providers. Even if you're under the threshold, treat customer details with care: strip names, phone numbers and addresses before you paste anything into an AI tool.
My verdict
Quick win for accessibility and search. Check it, because AI sometimes guesses wrong.
Common questions
What makes good alt text?
Describe what's in the image and why it's there, in plain language. Don't start with 'Image of'.
Should decorative images have alt text?
No. Purely decorative images should have empty alt text so screen readers skip them.
Does alt text help SEO?
It helps search engines understand images, and it's the right thing to do for people using screen readers.
Do this today
Open your homepage, find the three most important images, and give them proper alt text using the prompt.
More marketing use cases
- Write a month of social media post ideas
- Turn one blog post into five social posts
- Draft a monthly email newsletter
Next: Summarise long email threads · All marketing · Want a bot to do this automatically? See bot setup guides.