Most e-commerce stores leave alt text blank, paste in the filename, or write something generic like "product image." On a catalogue of 500 SKUs with 5 photos each, that's 2,500 missed signals to Google — and 2,500 missed entry points from Google Image Search. Alt text is one of the cheapest SEO fixes available to any online store. Here's exactly how to write it properly.
What Alt Text Is and Why It Matters
Alt text (the alt attribute on an <img> tag) is a short text description of what an image contains. It was designed for two purposes that both matter to e-commerce stores.
The first is accessibility. Screen readers used by visually impaired shoppers read alt text aloud when they encounter an image. A blind customer navigating your product page should be able to understand what they're looking at from your alt text alone. This is also a legal requirement in many jurisdictions under accessibility legislation.
The second is SEO. Search engines cannot see images the way humans do. They rely on alt text, file names, surrounding copy, and structured data to understand what an image depicts. Google uses this information to index images for Google Image Search and to validate product listings for Google Shopping. An image with no alt text is effectively invisible to search engines — it contributes no keyword signal and cannot rank in image results.
How Alt Text Affects E-Commerce SEO
Google Image Search is a buying channel that most e-commerce sellers ignore. A shopper searching for "dark brown leather chelsea boot men" on Google Images is a high-intent buyer at the moment of discovery. If your product image ranks there with accurate alt text, that click goes directly to your product page.
The traffic from Google Image Search is often more qualified than organic text search because the shopper has already seen the product visually before clicking. Bounce rates tend to be lower and time-on-page tends to be higher compared to generic search landing visits.
Beyond Image Search, alt text contributes to the overall keyword relevance of your product pages. Google evaluates every piece of content on a page — including image attributes — when determining what the page is about. A product page with well-written alt text on every image reinforces the topical signals already present in your title, copy, and structured data.
For Google Shopping, product images submitted via your feed are evaluated alongside the structured data in your listings. While Shopping primarily relies on your feed attributes, the on-page alt text of the corresponding landing page image provides a cross-reference signal that supports listing quality.
The Formula for Good Product Alt Text
Professional alt text for e-commerce product images follows a consistent structure. Use this formula as your template:
[Brand] [Product Name] [Key Attribute] [Colour / Material / Size if relevant] [Angle or View if relevant]
Working through this formula for a product photo of a brown leather boot:
- Good: "BLACKFOX DIGITAL edited men's leather chelsea boot dark brown side view"
- Too short: "shoe" — tells Google almost nothing
- Useless: "IMG_4521.jpg" — a raw camera filename with zero descriptive value
- Keyword stuffed: "buy cheap shoes leather shoes men shoes boots online" — a spam signal, not a description
Keep alt text between 5 and 15 words. Long descriptions become unwieldy for screen readers and dilute the keyword focus. Short descriptions leave out details that make the image findable. The formula above naturally lands in that range.
Include the brand name when it adds context — particularly if you're a brand selling your own products. Include colour and material because shoppers search with those terms. Include the angle or view on non-primary images so each alt text is distinct across the product gallery.
What to Avoid
Several common patterns actively harm SEO or provide no benefit:
- Keyword stuffing: Writing "buy cheap leather shoes men's leather shoes leather boots online" is not alt text — it's spam. Google penalises this pattern and screen readers read it aloud verbatim, which is a poor experience for visually impaired shoppers.
- Generic descriptions: "product image," "photo," "image 1" contribute no keyword signal and no accessibility value. They're worse than useless because they take up the attribute without earning anything from it.
- Leaving it blank: An empty alt attribute (alt="") is correct only for purely decorative images — icons, spacers, dividers. For product photos, a blank alt tag means Google gets no signal and screen readers skip the image entirely.
- Using the filename: Many platforms auto-populate alt text from the uploaded filename. If your filename is DSC_0042.jpg, that becomes your alt text — which tells Google nothing. Always override auto-populated alt text for product images.
Alt Text by Image Type
Most product listings use multiple images. Each image type serves a different purpose and should have alt text that matches what the image actually shows.
Main Product Image
This is the primary image shown in search results and at the top of the product page. It should carry the most complete alt text — brand, full product name, key attributes, colour, and material. This is the image most likely to rank in Google Image Search for your target keywords.
Angle Shots
Front, back, side, and three-quarter views each show different details. Include the angle explicitly: "men's leather chelsea boot dark brown back view" versus "men's leather chelsea boot dark brown front view." This keeps each alt text unique and ensures angle-specific searches can surface the right image.
Lifestyle Shots
Lifestyle images show the product in use or in a scene. Describe both the scene and the product: "woman wearing dark brown leather chelsea boots on cobblestone street autumn." These images can rank for aspirational search queries that pure product shots cannot reach.
Detail and Close-Up Shots
Close-ups of stitching, texture, hardware, or labels should describe the specific detail being shown: "leather chelsea boot double-stitch welt detail dark brown." This helps shoppers using screen readers understand what each close-up adds to their understanding of the product.
Platform-Specific Notes
How you set alt text depends on which platform your store runs on. Each major platform handles it differently.
Shopify
Shopify has a dedicated alt text field for every product image. Access it from the product editor by clicking the image and selecting "Edit alt text." It's straightforward — fill it in for every image on every product. Shopify does not auto-populate this field, so blank means blank.
WooCommerce
WooCommerce stores alt text at the media library level. When you upload an image, fill in the "Alternative Text" field in the attachment details panel. This value carries through to all uses of that image across your store. If the image was already uploaded without alt text, edit it directly in the Media Library.
Amazon
Amazon's architecture is different from a standard HTML storefront. Traditional alt text in the HTML sense is not seller-controlled on Amazon. Instead, alt text equivalents are set through A+ Content for brand-registered sellers and through backend keyword fields in the listing. Focus on product titles, bullet points, and search terms rather than HTML alt attributes when optimising for Amazon's search.
Etsy
Etsy sellers should fill in the image description field available on each listing image. This is Etsy's equivalent of alt text and is used for both accessibility and their internal search algorithm. Treat it identically to HTML alt text — descriptive, specific, no keyword stuffing.
File Naming Also Matters
Alt text and file names work together. Google reads both when indexing an image. A well-named file reinforces a well-written alt text; a poorly named file partially undermines it.
Before uploading any product image, rename the file descriptively:
- Good: mens-brown-leather-chelsea-boot-side.jpg
- Bad: DSC_0042.jpg or image (3).jpg
Use hyphens to separate words (not underscores — Google treats underscores as joiners, not separators). Keep it descriptive but not stuffed. The same formula that works for alt text works for file names: brand optional, product name, key attributes, angle.
Rename images before uploading. Renaming after upload and re-uploading creates duplicate URL issues and requires updating any existing links or structured data that pointed to the original file.
Quick Audit: Find Your Missing Alt Text
If your store has been live for any time without a systematic alt text process, you almost certainly have gaps. Here's how to find them quickly.
The fastest method is a site crawl with Screaming Frog SEO Spider (free up to 500 URLs). After crawling your site, go to the Images tab and filter by "Missing Alt Text." This gives you a list of every image URL on your site that has a blank alt attribute. Export the list and work through it product by product.
If you don't have Screaming Frog, you can inspect individual pages manually in any browser: right-click, "View Page Source," and search for alt="" to find blank instances. This is impractical at scale but useful for spot-checking your highest-traffic product pages first.
Fixing blank alt text across your existing catalogue is one of the fastest SEO wins available to any e-commerce store. It requires no new content, no link building, and no technical changes to your site architecture — just filling in a text field on images that are already live.
Scaling Alt Text Across a Large Catalogue
Writing alt text for 500 or more SKUs individually is a significant undertaking, but it becomes manageable with a batching strategy. The key is to avoid writing each alt text from scratch. Instead, group your products by category and write one template per category, then fill in the variables for each individual item.
For example, a footwear template might be: [Brand] [Gender] [Style] [Material] [Colour] [View]. Applying that template to 50 boots takes a fraction of the time writing 50 individual descriptions from scratch would require. The resulting alt texts are consistent, correctly structured, and distinct from one another because the variable values change.
A spreadsheet workflow makes this scalable: column A holds the image URL, column B holds the draft alt text built from the template, and column C marks whether it has been reviewed and approved. This gives you a complete audit trail and a file you can hand off to a team member or use to bulk-import via your platform's API or CSV import tool.
For the audit step, Screaming Frog exports a full image inventory with current alt text values. Import that export into your spreadsheet as your starting point, then fill column B for every blank or thin alt text row. Once column C is fully approved, use your platform's bulk edit tool or API to push the new values live in a single operation rather than editing images one at a time.
When to Use Structured Data Alongside Alt Text
Alt text and schema markup serve complementary purposes — they are not either-or choices. Alt text describes what a human sees in the image; structured data describes what the product is to a machine. Both signals reach Google through different channels and reinforce each other.
The schema.org/Product type includes an image property that points Google to the product image in a machine-readable format. This tells crawlers not just that an image exists, but that it is the authoritative visual representation of a specific product. Pairing this with a well-written alt text on the same image creates two independent signals that corroborate each other.
The ImageObject schema type goes further. It lets you specify a name, description, and contentUrl for the image itself — effectively a structured-data layer that reinforces everything your alt text already communicates on the page.
For Google Shopping, structured data rich results surface alongside organic listings in the Shopping tab. The on-page alt text of the landing page image is a supporting signal for those rich results. A listing with both strong Product schema and accurate alt text on every image is better positioned than one relying on either alone.
The practical rule: do not duplicate. Alt text describes the visual — what colour, angle, material, and detail the image shows. Schema markup describes the product — its name, brand, price, availability, and identifiers. Write each for its intended audience: alt text for humans and screen readers, schema for crawlers.
How BLACKFOX DIGITAL Handles Alt Text
When you commission product photo editing from BLACKFOX DIGITAL, you're investing in images that are ready to perform — not just visually, but technically. On request, we include suggested alt text for every delivered image as part of the delivery notes, written to the formula described above based on the product details you provide at briefing.
This means you receive edited images and the SEO copy to go with them in a single delivery, without the extra step of writing alt text for every image yourself after the fact.
If you'd like to see the quality of our editing before committing to a full order, our free trial lets you submit product photos and receive professionally edited samples with no obligation.
