Alt text lives in the alt attribute of an image tag and describes what's in the picture. Two audiences rely on it: people using screen readers who can't see the image, and search engines that can't fully interpret pixels. When an image fails to load, the alt text also shows up in its place. For local businesses, good alt text helps your photos rank in image search and adds relevant context to the page they sit on, which supports the page's overall topical relevance.
Why Alt Text Matters for SEO
Search engines read text far better than they read images. Alt text gives them a clear description to index, which is how photos end up in Google Images and how the surrounding page picks up extra relevance signals. Getting it right also improves accessibility, and accessible pages tend to be better structured overall.
- Helps images appear in image search results
- Adds relevant context to the page for search crawlers
- Makes content accessible to screen reader users
- Displays as fallback text if an image fails to load
- Can help a local business photo rank for location-based queries
How Alt Text Works
Alt text sits inside the alt attribute of an image tag, like alt="description here". Most website builders and CMS platforms give you a plain field to fill in when you upload or edit an image, so you rarely touch the raw HTML.
Google explains its own approach in the official Google Search documentation, which recommends descriptive text that reflects what the image actually shows in the context of the page.
How to Write and Check Alt Text
Describe the image accurately and concisely, as if explaining it to someone who can't see it. Keep it under roughly 125 characters so screen readers don't cut it off. Work a relevant keyword in only when it fits naturally.
- Add alt text in your CMS media library or image settings
- Read it aloud to check it makes sense without the picture
- Use a browser inspector to confirm the alt attribute is present
- Leave decorative images (spacers, background flourishes) with empty alt=""
- Audit your site with a crawler to find images missing alt text
Common Mistakes
The biggest errors come from either ignoring alt text or overloading it. Both hurt. Empty descriptions waste an opportunity, while stuffed ones read as spam to search engines and confuse screen reader users.
- Keyword stuffing, e.g. "plumber plumbing plumber near me best plumber"
- Leaving alt text blank on meaningful images
- Starting with "image of" or "picture of" (redundant)
- Writing generic file names like "IMG_4521" as the description
- Adding long alt text to purely decorative graphics
Best Practices
Treat alt text as a genuine description first and an SEO field second. For a local business, that means naming what's in the photo and, where it's true, the service or location it relates to. A dental practice photo could read "Hygienist cleaning a patient's teeth in our downtown office" rather than just "teeth cleaning."
Pair strong alt text with descriptive file names and a solid on-page setup. Our guide to on-page optimization at RankSphere covers how these elements work together.
- Be specific and describe the actual content
- Include location or service context only when relevant and accurate
- Keep it concise, ideally one short sentence
- Use descriptive, hyphenated file names to reinforce the alt text
- Prioritize accuracy over cramming in keywords
Related Terms
Alt text sits alongside several other on-page elements that shape how images and pages are understood.
- Image SEO: optimizing images for search across file name, size, and alt text
- Title attribute: tooltip text shown on hover, different from alt text
- Structured data: markup that gives search engines extra image context
- Accessibility (a11y): the broader practice alt text supports
- On-page SEO: the set of factors alt text contributes to