Free alt text generators: what they can and cannot do for your store
· alt text · tools · AI · free
A 600-product catalogue with 12 images per product means 7,200 alt text strings to write before you even think about French, German, or Polish variants. Writing them by hand is simply not realistic. A free alt text generator is the obvious first stop — but before you commit to one, it is worth being clear about what these tools actually produce and where they fall short of what WCAG requires.
What free alt text generators actually do
Free AI image description tools work by running your image through a vision model. The model analyses the visual contents — shapes, colours, objects, text it can read — and produces a short natural-language description. Most free tools wrap a publicly available model (typically one from a major US provider) in a simple interface where you upload an image and receive a text output.
The input is always the pixel data. The model sees what the image shows; it does not know the product name, the brand, the price, the material composition, or the size range. It cannot see your CMS, your product catalogue, or the page context the image appears on. It describes what is visually present.
For a photograph of a running shoe, a free generator might produce: "White athletic shoe with blue laces on a grey background." That is a reasonable visual description. Whether it is a good alt text depends on what the image is meant to communicate — which brings us to the gap.
Where free tools fall short
WCAG 1.1.1 requires that the alt text conveys the equivalent purpose of the image to someone who cannot see it. On a product page, the purpose is commercial: the shopper needs to understand what they are looking at well enough to make a purchase decision.
"White athletic shoe with blue laces" fails that purpose if the product is a Nike Air Zoom Pegasus 41 in White/Royal Blue, because a screen reader user cannot match the description to the product listing. They cannot distinguish it from 40 other white trainers in the catalogue. The alt text is visually accurate but commercially useless.
Free generators also have no knowledge of colour variants. If you sell a sofa in twelve colourways, a free tool will describe whatever colour is in the photograph it sees — but it cannot tag the description to a specific variant SKU or flag that the image is being reused across variants.
There is also the language problem. The European Accessibility Act requires accessibility in all 24 official EU languages for services offered across member states. A free generator typically produces output in one language. Running 7,200 images through it once for English, then again for each of 23 other languages, assuming the tool supports them, is not a scalable workflow.
Tool comparison
| Tool | WCAG coverage | Languages | Shopify integration | Price |
|---|---|---|---|---|
| Altvisor | WCAG 2.1 AA (with review) | 24 EU languages | Yes | Free tier, paid from €19/mo |
| Free AI image captioneers (generic) | Visual description only | Typically English only | None | Free |
| Screaming Frog + manual | Audit only, no generation | N/A | None | Free up to 500 URLs |
| Adobe Sensei (within Adobe CC) | Visual description only | Limited | None | Included in CC subscription |
| WordPress AI plugins (varied) | Visual description only | English-focused | WooCommerce partial | Free to ~€5/mo |
When free tools are good enough
There are situations where a free generator is entirely appropriate.
Small catalogues — under 50 products — where you can review every output before publishing. If each piece of generated text gets a human read and a manual correction where needed, a free tool gets you 70 percent of the way there quickly.
One-off audits where you need to assess how much alt text you are missing before deciding on a budget. A free scan or a batch through a free generator gives you a number. That number helps justify a tooling decision.
Testing and prototyping. If you are building a new product page template and want to see how alt text looks in context before setting up a proper workflow, free tools are fine. They give you placeholder text that is better than nothing.
The common thread: free tools work when the output is a first draft that a human will review, not a final artefact that will go directly into production.
The case for subscription tools on larger stores
At 500 products and above, the economics shift. A human reviewing 7,200 alt texts at five minutes each is 600 hours of work. A subscription tool that generates context-aware, brand-aware alt text — output you can approve or lightly edit rather than rewrite — reduces that to a fraction.
The more meaningful difference for EU stores is language coverage. The EAA applies to businesses selling to customers across member states. If your store ships to Germany, Poland, France, and Spain, your product content — including alt text — must be accessible in each language. That means generating and maintaining equivalent alt text in German (de), Polish (pl), French (fr), and Spanish (es) as a minimum. All 24 official EU languages are required if your target market spans the full EU.
A subscription tool that handles generation across all 24 languages from a single product image upload makes that requirement manageable. Rerunning a free tool 24 times per image, reviewing each output in a language you may not speak fluently, and maintaining consistency across variant images is a different kind of problem altogether.
Consistency matters for compliance audits too. An accessibility statement under EAA Annex V requires that you document your conformance status. A patchwork of manually written, machine-generated, and forgotten alt texts is difficult to audit. A workflow where every image passes through a consistent generation and review process gives you a clean record.
Run a free WCAG scan on your storefront to see exactly where you stand — then start free to fix image alt text at scale.