Alt text is one of the smallest pieces of copy on a product page and one of the most neglected. Many stores have none, or the filename, or the same keyword-packed phrase on every image. That is a missed accessibility obligation and a missed chance to describe the product accurately, both of which matter when a shopper using a screen reader is trying to decide whether to buy.
This guide shows what good product alt text looks like, with examples for each kind of image, a formula you can use, a way to produce it across a large catalogue and the mistakes to avoid. It is closely related to product title SEO and the broader work of cleaning catalogue data. Guidance on accessibility and search evolves, so we link to the primary sources at the end.
What alt text is for
- Accessibility. Screen readers read the alt text aloud so that a person who cannot see the image understands what it shows.
- Fallback. If an image fails to load, or the connection is slow, the browser may show the alt text.
- Search understanding. Search engines use alt text, with other signals, to understand what an image shows. Google’s image guidance recommends useful, information-rich alt text that fits the content.
- Image search. Descriptive text can help an image appear for relevant queries.
The order of importance is the order of that list. Write for the person first. Text that serves them tends to serve search too, and text written only for search tends to harm both.
The basic formula
Write a short, natural description of what the image shows, starting with the product type and adding the detail that matters in that image. There is no need to say “image of” or “photo of”, since the screen reader already announces that it is an image.
| Element | Example | When to include |
|---|---|---|
| Product type | Linen tablecloth | Always |
| Key attribute | in natural oatmeal | Colour, material or style that the image shows |
| What is happening | on a wooden dining table with plates and glasses | Lifestyle and in-use images |
| Detail visible | close-up of the hemmed edge | Detail shots |
| Brand or model | Northline | Where it helps identify the product |
Examples by image type
| Image type | Weak alt text | Better alt text |
|---|---|---|
| Main product on white | tablecloth | Northline natural linen tablecloth, rectangular, on a white background |
| Lifestyle | IMG_4821.jpg | Natural linen tablecloth on a wooden dining table set with white plates and glasses |
| Detail | best linen tablecloth cheap linen tablecloth buy linen tablecloth | Close-up of the hemmed edge and stitching on the linen tablecloth |
| Colour variant | tablecloth 2 | Linen tablecloth in dark green, folded |
| Size chart | chart | Size chart: small 140 x 180 cm, medium 140 x 220 cm, large 140 x 280 cm |
| Packaging | box | Linen tablecloth in a recycled cardboard gift box with ribbon |
| Model wearing | model | Woman wearing a navy waterproof hooded jacket, walking on a city street |
| Infographic with text | infographic | Diagram showing the jacket’s three layers: outer shell, waterproof membrane and inner lining |
Notice how the better versions differ: they say what the image shows, they differ between images of the same product and they are readable aloud. A screen reader user moving through a product page should hear a sequence that makes sense, not the same phrase six times.
What to do with special cases
- Decorative images. Dividers, background patterns and icons that add no information should have empty alt text (alt=""), so screen readers skip them.
- Images that contain text. Convey the text. If it is long, put it in the page as real text and keep the alt text short.
- Linked images. If an image is a link or a button, the alt text should describe the destination or action, such as “View size guide”.
- Repeated images. If the same photo appears twice, the second can be empty if it adds nothing.
- Variants that look alike. Say how they differ: colour, pattern or size.
- Sensitive content. Describe plainly and respectfully; do not guess at people’s characteristics.
How long should alt text be?
Short enough to be read comfortably, long enough to be useful. A single sentence or phrase is normal. Very long strings are tiresome in a screen reader and look like stuffing. Some accessibility guidance suggests keeping to a modest number of words and putting longer descriptions in the page text. Use your judgement: a plain product photo needs ten words; a diagram might need twenty and a text alternative nearby.
Keyword stuffing and why it fails
Putting every search term into every alt attribute is a common mistake. It makes pages unpleasant for screen reader users, it is repetitive across images and search engines have long advised against it. The better approach is to use the words that fit the image. If the product type or colour is a keyword you care about, it will appear naturally. If the term does not describe the image, leave it out.
Writing alt text at scale
A store with hundreds or thousands of images needs a process. Alt text can be generated from structured data, and in some cases from the image itself using a vision model, but both need rules and review.
| Method | How it works | Strengths | Cautions |
|---|---|---|---|
| Template from product data | Combine product type, colour, material and image position | Consistent, cheap | Generic; cannot describe what a lifestyle image shows |
| Vision model draft | A model describes each image; rules shape the output | Specific to the image | Can misidentify items; needs review and policy on style |
| Hybrid | Template for plain images, model for lifestyle and detail shots | Balanced | Needs image type classification |
| Manual for key products | A person writes the alt text for the best sellers | Highest quality | Does not scale alone |
A practical approach is to classify images by type, apply a template to plain product shots, use a model for lifestyle and detail shots, check a sample of each and write the best sellers by hand. This is part of our product data enrichment work and our product SEO titles and meta tags service, and the results are loaded with bulk product upload.
Rules to give a model
- Describe only what is visible in the image.
- Start with the product type; do not begin with “image of”.
- Mention colour, material or setting when visible.
- Keep to one short sentence.
- Do not add claims, prices or promotional words.
- Do not guess at brand, model or size if not visible; use the product data for those.
- If the image is decorative, return empty text.
- Use plain language.
Where to enter alt text
Most platforms have a field for it. In Shopify you can edit alt text for each product image in the admin, and it can be updated in bulk through a CSV import or the API. WooCommerce stores alt text in the media library. Page builders and themes sometimes add their own alt fields. Check one product page in the live site after a bulk update by viewing the source or using a browser accessibility tool to confirm the text appears.
A worked example
A store has 2,400 product images and none have alt text. A person writing 12 words of alt text takes about 40 seconds per image, which is 27 hours. A hybrid workflow classifies images, generates drafts and flags images where the model’s confidence is low; a person reviews 10 percent of drafts and fixes the flagged ones. The work takes about 6 hours of review time. At $20 an hour, that is $120 against $540 for the manual route, and the result is more consistent. The saving is modest, but the real benefit is completeness: every image gets a description, and the pipeline keeps working as new products arrive. The figures are illustrative.
Checklist
- Every meaningful product image has a specific description.
- Decorative images have empty alt text.
- Images of the same product have different text.
- Images with text convey the text or have a nearby text alternative.
- No keyword stuffing or promotional words.
- Colour and material mentioned only when visible.
- Updated when photos change.
- A sample checked with a screen reader.
Sources and further reading
Figures and rules in this guide come from the primary pages below. Platform limits and prices change, so open the page before you build on a number.
- Google Search Central: image SEO best practices, guidance on alt text and image context
- W3C Web Accessibility Initiative: alt decision tree, how to decide what alt text an image needs
- Shopify Help Center: media, adding and editing product images and alt text