Alt text and captions for listing photos.

Alt text, captions and MLS photo remarks

Three different bits of text can travel with a listing photo, and they do different jobs:

• Alt text is the alt attribute in a web page's HTML. Most visitors never see it. Screen readers read it aloud, browsers show it when an image fails to load, and search engines use it to understand the image.
• A caption is visible text under or over the photo, for everyone. It can add information the photo can't show, like "New roof, 2024".
• MLS photo remarks or descriptions are whatever fields your MLS provides for each photo. Whether they exist, how long they can be and where they syndicate depends on the MLS, so check yours.

This guide is mostly about alt text on your own website, property pages and blog posts, where you control the HTML or the website builder's image settings. The same writing habits help with captions and MLS remarks.

What the accessibility guidance says

The World Wide Web Consortium's accessibility team (W3C WAI) publishes an alt decision tree that sorts images into a few cases. For an informative image, such as a photograph that carries meaning, it says to "use a brief description of the image in a way that conveys that meaning in the alt attribute." For an image that's purely decorative, it says to "use an empty alt attribute," so screen readers skip it. For an image inside a link or button, the alt text should "communicate the destination of the link or action taken." For a complex image like a chart, it says to "include the information contained in the image elsewhere on the page."

In the United States, the Department of Justice's 2022 guidance on web accessibility and the ADA explains that the ADA's requirements apply to the goods and services businesses open to the public offer on the web. On images, it says text alternatives "convey the purpose of an image, including pictures, illustrations, charts, etc." and that "the text should be short and descriptive." The same guidance notes that the Department "does not have a regulation setting out detailed standards" and that businesses "have flexibility in how they comply," while pointing to existing technical standards as helpful guidance. What that means for a particular brokerage or agent website is a legal question; this guide only covers how to write the text well.

What Google says

Google's image SEO best practices call alt text "the most important attribute when it comes to providing more metadata for an image," and say Google uses it "along with computer vision algorithms and the contents of the page" to understand what an image shows. The same page warns: "Avoid filling alt attributes with keywords," because it "results in a negative user experience and may cause your site to be seen as spam." Its own example progresses from no alt text, to a string of keywords (bad), to "puppy" (better), to "Dalmatian puppy playing fetch" (best): specific and natural, not stuffed.

For agents, that rules out the common habit of putting "Woodbridge VA real estate agent homes for sale" on every photo. One plain description per photo serves both the visitor and the search engine.

A simple formula for listing photos

For most listing photos, alt text can follow one pattern: the space, then one or two features a buyer would want to know about and can see in the photo. Keep it to a sentence or less. You don't need to start with "photo of" or "image of"; screen readers already announce that it's an image.

Describe what's visible, in the words a buyer would use. Leave out opinions ("stunning", "gorgeous") and claims the photo can't support ("quiet street", "perfect starter home"). Those belong, if anywhere, in the description, where they still need to be accurate.

Fair Housing applies to alt text too

Alt text and captions are part of your advertising, even if most visitors never see the alt attribute. The same rules apply as in a listing description: describe the property and its features, not who lives there or who "should" buy it. "Bedroom with a window seat and built-in shelves" is fine. "Perfect for a growing family" or a caption about the type of people in the neighborhood is not. If a photo shows people, which listing photos generally shouldn't, don't describe them. Our guide to Fair Housing-safe listing descriptions has the longer list of phrases to avoid and what to say instead.

Edited photos need honest text. A virtually staged room should say so in the caption and the alt text, for example "Living room, virtually staged, with a fireplace and two large windows." The same goes for virtual twilight. Our virtual staging disclosure guide covers the MLS side.

Floor plans, maps and graphics

A floor plan is a complex image: alt text like "Floor plan" says almost nothing, and squeezing every room into the alt attribute makes it unreadable. Follow the W3C's advice for complex images. Use short alt text such as "Floor plan of the main level," and put the useful information in real text on the page: the room list with dimensions, the total finished square footage and how it was measured. See our guide to floor plans and square footage for what to include.

Graphics with words in them, like a "Just Listed" flyer image or an open house graphic, need the words in the alt text if they aren't already written on the page: "Open house Saturday 1 to 3 PM, 123 Example Street." Logos that link to your home page should describe the destination, such as "Home," not the logo's colors.

Thumbnails, galleries and lightboxes

Property pages often show small thumbnails that open a larger version. If the thumbnail is a link, its alt text should still describe the photo, so a screen reader user knows which room they're about to open. If the same photo appears twice on the page, for example as a hero image and again in the gallery, the second copy can describe it more briefly. Purely decorative images, such as a background texture or a divider, should have empty alt text so they're skipped.

Many website builders and IDX tools fill alt text automatically with the address and a number. That's better than nothing but not much better. Check whether your platform lets you edit the alt text for each photo; if it does, the formula above takes a few minutes per listing.

A workflow that takes ten minutes

The easiest time to write alt text is when you're ordering the gallery for the MLS, because you're already looking at each photo in sequence. Keep a running document with one line per photo: the file name and the description. Reuse those lines for your website, your property page and any blog post or social carousel that supports alt text. If you use AI tools to draft descriptions, read every line: they often guess wrong about materials, add opinions or describe things that aren't in the photo.

When the listing sells and you move the photos to a "Just Sold" post or a portfolio page, the alt text can go with them. Check first that your license with the photographer covers that use; our guide to who owns listing photos explains why.

Quick checklist

1. Every informative photo has alt text; decorative images have empty alt text.
2. Each line names the space and one or two visible features.
3. No keyword lists, no addresses repeated on every photo, no "image of".
4. No opinions or claims the photo can't support.
5. Nothing about people, and nothing about who the home is "for".
6. Virtually staged or edited photos say so.
7. Floor plans get short alt text plus the details in real text on the page.
8. Graphics with words include those words.
9. Linked thumbnails describe the photo they open.
10. AI-drafted text is read and corrected before it's published.