PrestaShop image alt text: describing hundreds of photos for Google and screen readers
PrestaShop image alt text is the image caption you enter on the product page next to each photo. The store inserts it as alternative text, which Google Images and a blind person's screen reader both read. Good alt text describes what is visible: the product name, colour and view. You can fill hundreds of empty captions in batches, starting with your best sellers.
Author: The TellMyShop team. A guide for PrestaShop store owners: the cause, the manual fix and the same work in a chat conversation.
Last updated: · 5 min read
Why does a product photo need a description if the customer can see it?
Because not everyone who visits the store sees the image. A blind person hears the alt text instead of the picture. Google's crawler does not look at images the way a person does either, and uses the text around them, including the alt.
Google says this plainly in its SEO guidelines for Google Images: descriptive alt text helps it understand what an image shows. The W3C images tutorial adds the other side: alt text should convey the same information the image gives. For a product that is usually the colour, the variant and the angle we are looking from.
Then there is the case where the image does not load. The browser shows the alt text in its place, as MDN describes.
What does good product image alt text look like?
Short, specific and different for each image of the same product. Compare three versions for one gallery.
| Image | Weak alt | Overdone alt | Good alt |
|---|---|---|---|
| cover | Nora lantern | lantern garden lanterns cheap metal lanterns shop | Nora lantern, black, 40 cm, front view |
| second | Nora lantern | Nora lantern best garden lantern | Nora lantern, black, with a candle inside |
| third | (empty) | gift lantern patio lantern lantern | Nora lantern on a patio in the evening |
The weak alt repeats the name, so three images sound the same. The overdone one is a list of phrases nobody wants to hear in a screen reader. The good one says how this image differs from the others.
When does alt text matter for sales?
Most of all in categories where customers search by image. Furniture, lamps, clothing, decorations: here many people start in Google Images and click the photo that fits. An image with a good description on the right product page has a better chance that Google understands what it shows.
The other side is accessibility. Since June 2025 the European Accessibility Act has applied in the EU. It also covers many online stores, with exceptions for the smallest businesses. Described images are one of the basic elements of an accessible page. Check whether your store falls under these rules. Alt text is worth having anyway.
Image descriptions will not replace a good product name and description. They are one of the signals that together tell Google what you sell.
How much work is it in the back office?
One click per image, and there are several times more images than products. Monday, 21:40. You open a product, click the first image, type the caption, save, click the second. In a category of 80 products with 4 images each, that is 320 descriptions. In a store with two languages, twice as many.
The back office has no bulk editing for captions. On forums you can find database queries or modules that put the product name into every empty caption, as Sitolog describes. It is quick, but it gives you the result from the first column of the table: every image with the same description.
How do you fill in image alt text step by step?
You start with a list of what is missing, not with the first product in the catalogue.
- Check the scale. How many images have no caption, and in which categories.
- Choose the order. First the products that sell, and the categories that get traffic from Google.
- Set a pattern. For example: name, colour or variant, view. The pattern keeps the descriptions consistent.
- Describe only empty captions. Descriptions someone wrote by hand are usually better than the pattern.
- Review a sample. A few products with different galleries will tell you whether the pattern works.
- Repeat for the second language, if the store has one.
How do you describe a whole category's images with one request?
You describe the pattern, and your chat (Claude or ChatGPT) reads the names, variants and image order of each product. Then it shows a preview: image by image, the current caption and the new one. One batch is up to 100 images.
You: Add descriptions to the images with no alt text in the Lanterns category. Name, colour and view if there are several images. Leave existing ones alone.
Your chat: In Lanterns, 212 images have no caption. The first batch is 100 images. Examples:
Descriptions that already exist stay unchanged.
You: Approved.
Your chat: Saved. You can undo the batch with one request from the change history. Shall I show the second batch?
Card status: waiting for your “yes”old version: Nora lantern, image 1: (empty caption)
new version: Nora lantern, black, front view
old version: Nora lantern, image 2: (empty caption)
new version: Nora lantern, black, with a candle inside
old version: Mila lantern, image 1: (empty caption)
new version: Mila lantern, white, side view
One request covers the whole category, and you approve the batches one after another, each after reading the preview. You will see the number of missing alt texts and suggested descriptions in TellMyShop Free. The captions themselves are saved only by TellMyShop Pro, right after licence activation, with no switch needed. The wording of such a request is shown in the use case describing hundreds of product images at once. Want to improve the whole pages of your best sellers while you are at it? Have a look at improving the pages of 20 best sellers. The article on how to build a product page that sells will help too.
What will alt text not fix?
It will not fix an image that is small, dark or shows a different product. Nor will it replace the product description or the file name. The chat describes images based on the product data and the order in the gallery, not the image itself. If the third image shows something unusual, for example dimensions on a drawing, fix that description by hand or mention it in your request.
Questions and answers
Where do you enter image alt text in PrestaShop?
On the product page in the back office, next to the image. You click the image in the product gallery and type the caption. PrestaShop uses it as the alternative text on the store front. The caption is separate for each language, so in a store with two languages you describe each image twice, once per language.
What happens when an image caption is empty?
It depends on the theme. Many themes then insert the product name, so all images of one product have the same description. A screen reader reads the same thing five times, and Google cannot tell how a side view differs from a back view. So an empty alt usually means a repeated name.
How long should product image alt text be?
Short, usually one sentence without a full stop. The product name, the feature that sets the image apart and the view are enough. PrestaShop allows a caption of up to 128 characters, but good descriptions are usually much shorter. Do not type a list of keywords, because a screen reader will read it out in full.
Will the chat overwrite alt texts I already wrote?
Not if you ask only for the empty ones. The chat can change only empty captions and leave the ones you have. In the preview you see each image with its current and new description. Saving happens after your approval, and you can undo the whole batch with one request from the change history.
Can I check for missing alt text for free?
Yes. In TellMyShop Free the chat goes through your products and shows how many images have no description and in which categories. You will see the suggested descriptions too. Saving new captions requires TellMyShop Pro. The chat saves them in batches of up to 100 images, each after a preview and your approval, and you can undo them.
PrestaShop is a registered trademark of PrestaShop SA. Claude is a trademark of Anthropic PBC. ChatGPT and OpenAI are trademarks of OpenAI. TellMyShop is not affiliated with these companies.