If your online store has hundreds (or thousands) of product photos, the tiny alt text attribute attached to each image is one of the most underused SEO levers you have. Done right, alt text for product images helps screen readers describe what shoppers can’t see, improves your ranking in Google Image search, and even rescues your page when an image fails to load.
In this guide, we go beyond the generic advice. You will get 7 concrete rules, before/after rewrites for apparel, electronics and homeware, a quick comparison table, and a copy-paste FAQ. Let’s dive in.
What is alt text (and why product pages need it)
Alt text (alternative text) is a short written description added to an image’s HTML tag. It serves three jobs at once:
- Accessibility: screen readers read it aloud to visually impaired users.
- SEO: Google uses it to understand image content and rank it in Image search.
- Fallback: it appears when the image fails to load or is blocked.
On an e-commerce store, every product image, swatch, lifestyle shot and zoom-in needs alt text. Decorative icons (like a divider line) should use empty alt="" so screen readers skip them.
The 7 rules for writing alt text for product images
Rule 1: Lead with what the product actually is
Start with the product type, then add distinctive attributes. A screen reader user (and Google’s crawler) should know within the first 3 words what they are looking at.
- Before: “IMG_4521.jpg”
- After: “Men’s navy blue cotton crewneck t-shirt, front view”
Rule 2: Include color, size, material, and angle
These are the exact filters shoppers use in Google Images. If your alt text contains them, you are aligned with real search queries.
Rule 3: Stay under 125 characters
Most screen readers cut off after 125 characters. Keep it scannable. If you need more detail, put it in the product description, not the alt attribute.
Rule 4: Skip “image of” or “picture of”
Screen readers already announce that it’s an image. Saying “image of a red mug” wastes characters and sounds redundant.
Rule 5: Use your target keyword once, naturally
Keyword stuffing in alt text is a known spam signal. Use the keyword once, only if it genuinely describes the picture.
- Bad: “running shoes, best running shoes, cheap running shoes, buy running shoes online”
- Good: “Black Nike Pegasus 41 men’s running shoes, side profile”
Rule 6: Differentiate each image on the same product page
A product gallery often has 5 to 8 photos. Give each one a unique alt text reflecting what the photo actually shows (front, back, detail, lifestyle, scale).
Rule 7: Match the alt text to the page’s intent
The alt text should reinforce the page topic. On a category page, lean broader (“women’s leather ankle boots”). On a product page, lean specific (“Sienna brown leather ankle boots, 5 cm block heel, size 38”).
Before / After examples by product type
Apparel
| Image | Before | After |
|---|---|---|
| Main shot | dress1.png | Emerald green silk wrap midi dress, front view on white background |
| Back shot | dress back | Back view of emerald green silk wrap dress showing tie closure |
| Lifestyle | model outdoor | Woman wearing emerald green silk midi dress at outdoor garden party |
Electronics
| Image | Before | After |
|---|---|---|
| Hero | headphones.jpg | Sony WH-1000XM5 wireless noise-cancelling headphones in matte black |
| Detail | buttons close up | Close-up of touch controls on right ear cup of Sony WH-1000XM5 |
| In box | unbox | Sony WH-1000XM5 headphones with carrying case, USB-C and audio cable |
Homeware
| Image | Before | After |
|---|---|---|
| Product | lamp.png | Brass tripod floor lamp with white linen shade, 150 cm tall |
| In context | living room lamp | Brass tripod floor lamp lit in a modern Scandinavian living room |
| Scale | dimensions | Brass tripod floor lamp dimensions diagram, height 150 cm, base 60 cm |
How to add alt text in popular platforms
- Shopify: Products > select product > click the image > “Add alt text”.
- WooCommerce: Edit product > Product image > click the image in the Media Library > fill the “Alternative text” field.
- Squarespace: Open the product editor > hover over the image > three dots > Edit metadata.
- Magento / Adobe Commerce: Catalog > Products > Images and Videos > click the image > “Alt Text”.
- Custom HTML: simply add the attribute:
<img src="shoe.jpg" alt="Black Nike Pegasus 41 men's running shoes, side profile">
Common mistakes to avoid
- Leaving the alt attribute empty on a meaningful product image.
- Copy-pasting the product title into every gallery image.
- Stuffing 10 keywords separated by commas.
- Using the file name (“DSC_0921.jpg”) as alt text.
- Describing images that are purely decorative (use
alt=""instead). - Forgetting alt text on variant swatches and zoom images.
Bonus: automating alt text at scale
If you have 5,000 SKUs, manual writing is unrealistic. A practical workflow in 2026:
- Use a template per category: {product name} + {color} + {key attribute} + {angle}.
- Generate first drafts with a vision AI model (Shopify Magic, OpenAI vision, Claude vision, etc.).
- Have a human reviewer correct the top 20% of products that drive 80% of revenue.
- Audit yearly with a tool like Screaming Frog (filter: images with missing or duplicate alt).
FAQ
Do product images really need alt text?
Yes. Alt text is required by accessibility standards (WCAG 2.2), it’s a ranking factor for Google Image search, and it acts as a fallback when images fail to load. Skipping it is a missed SEO and compliance opportunity.
How long should alt text be?
Aim for 80 to 125 characters. Most screen readers stop reading after about 125 characters, so put the essential info first.
Should I put my brand name in every alt text?
Only when the brand is visibly part of the product or relevant for search (e.g., “Nike Pegasus 41”). For unbranded category shots, skip it.
Is alt text the same as the image title attribute?
No. The title attribute creates a tooltip on hover and has minimal SEO value. The alt attribute is for accessibility and image search. Always prioritize alt.
Can I use the same alt text for multiple images of the same product?
No. Each photo shows a different angle, detail or context, so each alt text should be unique. Duplicates can be flagged as low quality by SEO auditing tools.
Does AI-generated alt text hurt SEO?
Not by itself. Google cares about accuracy and usefulness, not the author. AI drafts are fine as long as a human checks them and they match the actual image.
Final takeaway
Great alt text for product images is short, specific, unique per image, and written for humans first. Apply the 7 rules above across your catalog and you’ll see two wins compound over time: a more accessible store and a steady stream of free traffic from Google Images.