Alt text for Shopify stores: the complete guide

Nobody sits down to describe three thousand images.

It is the job that gets deleted from every to-do list, every quarter, in every store — and because nobody is counting, you cannot even say how bad it is. This guide fixes the second half of that. By the end of it you will know what alt text is for, what a good one looks like, where every one of them lives in Shopify, and how to find out — in about ten minutes, with no app installed — how much of your catalogue is actually described.

Who reads your alt text

Three audiences, and they want different things from the same sentence.

Google. Image search only surfaces images it can read. An image with no description is not ranked badly; it is not in the race. Alt text is also how Google understands what a page is about when the page is mostly photographs, which on a product page it usually is.

AI shopping agents. This is the newer one and it is moving fastest. An agent browsing your catalogue on a customer's behalf reads it as text. A silent image does not exist to it — and if the image was carrying the reason to buy, neither does the product.

Screen-reader users. A person who cannot see your photograph hears your alt text, or hears "image", or hears the filename. This is the audience the law cares about, and the one that tells you what a good description sounds like: if it would be useless read aloud, it is useless.

The three wants are less different than they look. Write the sentence that helps the person who cannot see the image, and you have written the one the other two want.

What Shopify itself says

Worth knowing before anything else, because it settles several arguments.

• 512 characters is the hard limit on the product alt text field.
• 125 characters or fewer is Shopify's recommended length.
• Skip "image of." Screen readers already announce that it is an image, so the words are pure overhead, twice.
• Keywords only where they describe. Work them in "only where they describe the image, such as product type, colour, material, model name, or use case." Stuffing is treated as a spam signal.
• Decorative images get an empty alt attribute — alt="", not a missing one — so screen readers skip them instead of announcing a background swirl.

Source: How To Write Image Alt Text for SEO and the Shopify Help Center.

For the standard behind the law, alt text is WCAG Success Criterion 1.1.1, Non-text Content, at Level A — the lowest conformance level, which is to say the least excusable one to fail.

What good looks like

Same product, three descriptions.

alt="IMG_2041-final-v3.jpg"

Missing, effectively. This is a filename that leaked into a field.

alt="buy mens organic tee best price free shipping"

Junk. It describes nothing, it reads as spam to Google, and out loud it is gibberish. Note that both of these count as covered in every alt text tool on the Shopify App Store, including the audit inside our own app until it grades them.

alt="Moss Green Organic Cotton Tee - Small - T-Shirts"

Weak, and this is the interesting one, because it is what a template produces and it looks fine. It is the product title. A shopper reading the page already has it from the heading; a screen-reader user hears it once per photograph; and it is identical across all six images of the product, so five of the six carry no information at all.

alt="Moss-green organic cotton tee folded flat, showing the ribbed collar and
embroidered leaf at the hem"

Good. It describes this photograph — the one the merchant chose to shoot because the title was not enough.

The five rules

1. Describe what is in the frame, not what the product is called.
2. One image, one sentence. If two images of a product share alt text, at least one of them is undescribed.
3. Roughly 125 characters. Long enough to be specific, short enough to be heard.
4. Never open with "image of", "picture of", or "photo of."
5. Empty alt="" for decoration. Dividers, swirls, spacer images. Silence is the correct description of something with nothing to say.

A sixth, for context: the same photograph can need different alt text in different places. On the product page it is the garment; in a blog post about dyeing it might be the colour.

Where alt text lives in Shopify

More places than most merchants expect, and the ones people miss are the ones that hold the biggest images.

• Product media. Admin → Products → the product → click a media item → alt text field → Save. This is the one everybody knows.
• Variant images. Attached to the media item, so they inherit from the product's media, but a variant-specific shot is its own image and deserves its own sentence.
• Collection images. Set on the collection, easy to forget entirely.
• Blog article images, including the featured image.
• Theme images. Banners, sliders, section imagery, campaign art. Admin → Online Store → Themes → Customize → click the section → Edit below the image. These are the largest, most prominent images on the store, and they are also the ones most likely to be entirely undescribed, because they are not in the product admin where people go looking.
• Theme-settings images. Some themes hold images in settings rather than sections. These cannot be reached by the Shopify API at all, which is worth knowing before you evaluate any tool that claims to cover "everything."

The ten-minute self-audit

No app. Do this before you evaluate any tool, including ours, because the number it gives you is the number every vendor's pitch has to beat.

1. Open your store, right-click any product image, choose Inspect.
2. Find the <img> tag and read its alt attribute.
3. Do this for twenty images: five bestsellers' primary photos, five detail or on-model shots, five theme or banner images, five blog images.
4. Sort each into four buckets:
   • Missing — empty or absent on a non-decorative image
   • Junk — a filename, or keywords strung together
   • Weak — the product title, or a template, or true of six images at once
   • Good — describes this specific photograph
5. Count the last bucket.

Most stores discover something they were not expecting: coverage is high and description is low. Fields are full. The words in them are the product title.

That gap is the entire point of this guide. Coverage is a count of non-empty fields. It is not a measure of whether anything was described, and every tool that reports a coverage percentage — ours included, until it grades — is reporting a number that can be 100% on a catalogue nobody can read.

Does this actually make you compliant?

No tool can promise that, and any that does is one to walk away from.

What is true: the European Accessibility Act has had ecommerce in scope since June 2025, web accessibility lawsuits in the US run into the thousands each year under the ADA, and unreadable images are the most visible, most easily automated-away gap on a typical storefront. Closing it with an audit trail is a materially better position than not. It is not a certificate, and this guide is not legal advice.

When to automate, and when not to

Do it by hand if you have fewer than a few hundred images, or your catalogue is stable. Twenty images is an afternoon. Two hundred is a week of afternoons, and you will write better alt text than any tool because you know why you shot the photograph.

Automate if the number is in the thousands, or new products land weekly, or you have tried twice already and the to-do line just moved to next quarter. At three thousand images the failure is not effort, it is that nothing grades what is already junk, nothing verifies each write, nothing catches the product you upload next Tuesday, and nobody is watching when it silently stops.

Whatever you choose, judge it on the same four buckets you just used by hand. Ask any vendor: does it grade what is already there, or only count it? Most count.

Find out where your store stands

Run the twenty-image audit above. It is free, it takes ten minutes, and it is yours whether or not you ever install anything.

If the number comes back worse than you expected and the catalogue is too big to fix by hand, Image Voice does the same four-bucket grade across your whole store — free, forever, no card, nothing written until you approve it. Run the free scan and see your number. If your alt text turns out to be fine, we will tell you that too.