The PrestaShop ALT tag (an image's alt attribute) is the text that Google and screen readers read in place of the visual. On a PrestaShop store, it's one of the few SEO fields left empty by default: the back office doesn't require it, the CSV import doesn't fill it, and the theme invents nothing. As a result, hundreds of products ship with alt="" or alt="IMG_4523.jpg" — invisible to Google Images and inaccessible to the visually impaired. This page explains where to fix the ALT tag in PrestaShop, how to write a good one, and how to process your entire catalog without spending your nights on it.
Why the ALT tag really matters on PrestaShop
Three concrete reasons, in order of business impact:
- Google Images traffic. In e-commerce (a dress, a shoe, a light fixture, a piece of jewelry), a significant share of searches starts in the Images tab. Without an ALT tag, Google doesn't know what your photo shows and won't rank it. A descriptive ALT lifts the thumbnail, which in turn drives clicks to the product page.
- Accessibility and compliance. WCAG (and its French implementation, RGAA) requires a text equivalent for every image that carries information. A screen reader literally announces the content of the
altattribute:alt="IMG_4523.jpg"is read out as "I-M-G underscore 4523 dot J-P-G". It's also a quality signal that Google associates with well-maintained sites. - Semantics and AEO. Answer engines (Google SGE, AI assistants) rely on ALT text to understand what a product actually looks like when the page itself is thin on text. A tag like "navy quilted jacket with a removable hood" anchors the product far better than a vague marketing paragraph.
Where to edit the ALT tag in the PrestaShop back office
A product image's alt attribute is set image by image, by hand:
Catalog > Products > (open a product) > Images tab. Click a thumbnail: a side panel opens with the "Caption" field (labeled "Légende" in French). This field is what feeds the alt attribute in the HTML rendered on the storefront. Fill it in for each image and save.
Important version notes:
- PrestaShop 1.7 and 8: the field is called "Image caption" in the side panel of the Images tab. It's multilingual — remember to fill in each flag, otherwise the FR version is empty in EN.
- PrestaShop 9: same logic, redesigned back office; the field stays in the product's Images tab.
- Category and CMS images: these have their own ALT field under Catalog > Categories > (a category) > Image, often overlooked even though those pages capture top-of-funnel category traffic.
Front-end check: open the product page, right-click the image > "Inspect", and read the alt="..." attribute in the HTML. That's the only reliable proof that your caption actually made it into the ALT tag.
ALT tags generated by the theme (the template trap)
Many PrestaShop themes inject a default value when the caption is empty, via the Smarty variable {$image.legend} in the product.tpl / product-cover.tpl templates. Some themes replace the blank with the raw product name, repeated across all 8 photos: alt="Aurore Dress", alt="Aurore Dress", alt="Aurore Dress"… Google then sees 8 semantically identical images. It's better than nothing, but it's duplicate content that caps your chances on Google Images. The fix isn't to touch the template — it's to fill in distinct captions per image.
The formula for a good ALT tag
An effective ALT tag describes what the eye sees, in natural language, without stuffing. Copy-paste template:
[Product type] [dominant visual attribute] [color] [material] [distinctive detail]
Target length: 80 to 125 characters. Below 40, it's too thin; above 125, screen readers truncate it and Google ignores the end.
Real before / after examples:
- ❌
IMG_4523.jpg - ❌
alt=""(empty) - ⚠️
dress(accurate but starved) - ✅
Sky-blue long linen summer dress with an adjustable belt and a V-neck
Another case:
- ❌
shoe-ref-8891-v2-final.png - ✅
White leather high-top sneaker with a lugged sole and matching flat laces
For a multi-photo product, differentiate each angle:
- Photo 1 (packshot):
Beige canvas tote bag with double handles, front view - Photo 2 (detail):
Magnetic closure and zipped inner pocket of the beige canvas tote - Photo 3 (worn):
Beige canvas tote bag carried on the shoulder, casual outfit
Common mistakes (with the exact example)
- Keyword stuffing.
alt="dress dress cheap dress summer dress linen dress women dress sale"is keyword stuffing — penalized and unreadable to a screen reader. A single natural occurrence of the term is enough. - Copying the file name.
alt="DSC_0042"provides no information whatsoever. - Copying the TITLE tag. The ALT describes the image, not the page. "Buy a cheap linen dress – Store" has no business in an
alt. - Describing a decorative image. A separator icon or a gradient background should have
alt=""(deliberately empty) so the screen reader skips it. You only add an ALT to images that carry meaning. - Forgetting the languages. A caption filled in FR but empty in EN/ES/IT leaves the English version with no ALT. The field is multilingual: every flag counts.
- Blocking
/img/in robots.txt. If you disallow the images folder from crawling, no ALT will help: Google will never see the visuals. Check Advanced Parameters > SEO & URLs and your generatedrobots.txt.
Automating the ALT tag across the whole catalog
Filling in the caption of 8 images across 400 references by hand is 3,200 fields. Two realistic approaches:
The bulk ALT field via variable. Under Advanced Parameters > SEO & URLs, PrestaShop doesn't natively offer a global ALT, but most themes accept the {$product.name} variable in the image template. This puts the product name on every photo — a uniform stopgap, not a per-visual optimization.
Visual AI generation (Fexa AI). Rather than writing each tag, Fexa AI analyzes the visual and the product attributes (color, material, shape) to produce a descriptive, distinct ALT tag, per image and per language. In the Optimization Panel, check "Image Alts" then "Generate": the AI writes a rich tag for each image. The ALTs are generated at the same time as the rest of the sheet (title, description, meta), for just 1 credit per optimized language (see the credit system).
Review and approve your ALTs (including in batch)
You stay in control of every tag. In batch optimization, the preview shows the generated ALT tags image by image, alongside the rest of the sheet.
- Review each ALT before publishing — the AI describes what it sees, but you know the exact reference.
- Uncheck a specific tag (or the whole ALT group) to exclude it from the apply step, useful if some images are already well described.
- Only checked tags are written to your shop.
It's the same per-field control as for titles, descriptions and FAQ.
PrestaShop ALT tag FAQ
Where is the ALT tag in PrestaShop?
Under Catalog > Products > Images tab: click a thumbnail and fill in the "Caption" field. This caption becomes the alt attribute on the storefront.
How long should an ALT tag be? Aim for 80 to 125 characters: enough to describe the image and place the keyword once, without being truncated by screen readers or ignored by Google.
Should every image have an ALT?
No. Images that carry information (product photos, category visuals) should have a descriptive ALT. Purely decorative images should have an empty alt="" so screen readers ignore them.
Is the ALT tag a Google ranking factor? Yes for Google Images, which relies heavily on it. In classic web search it's a secondary but real signal, and an accessibility criterion that Google values.
How do I fix hundreds of images at once? Manually, you have to go image by image in the Images tab. To process the whole catalog, a module like Fexa AI generates a distinct ALT tag per image and per language by analyzing the visual, then you approve in batch before publishing.
Take action. Run your free PrestaShop SEO audit — no install, no credit card — to spot your images without an ALT tag, or install the Fexa AI module to generate your alt text across the whole catalog.
Next step: FAQ & structured data: Rich Snippets and voice search