Why Image Alt Text Matters for SEO and Accessibility
Alt text describes images for people using screen readers and for search engines. Here's how to write it well, with examples, and when to leave it empty.
Key takeaways
- Alt text is read aloud by screen readers and helps search engines understand images.
- Describe what the image shows and why it's there, in a short sentence.
- Decorative images should have empty alt text (alt="").
- Don't stuff keywords; describe the image accurately.
Alt text (the alt attribute on an image) is a short written description of an image. It’s read aloud by screen readers for people with visual impairments, shown if an image fails to load, and used by search engines to understand what the image shows.
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<img src="meta-ads-manager-columns.png" alt="Meta Ads Manager with custom columns for cost per purchase and ROAS">
Why it matters
- Accessibility: without it, screen reader users miss the information in your images. In many countries, accessibility is also a legal requirement for some websites.
- Google Images: alt text, along with the surrounding text and file name, helps your images appear in image search.
- Context: it reinforces what the page is about, especially for product and how-to content.
How to write good alt text
- Describe what the image shows and why it’s on the page
- Keep it concise: usually one short sentence
- Be specific: “Red cotton kurta with white embroidery, front view” beats “kurta”
- Include a keyword only if it naturally describes the image
- Don’t start with “Image of…” (screen readers already announce it’s an image)
Examples
| Image | Weak alt text | Better alt text |
|---|---|---|
| Product photo | “shoes” | “Black leather Peshawari chappal, side view” |
| Screenshot | “screenshot” | “Search Console Page indexing report showing 120 pages not indexed” |
| Chart | “chart” | “Line chart: organic clicks fell 40% after the March core update” |
| Team photo | “team” | “Our audit team reviewing a client’s Google Ads account” |
| Keyword-stuffed | “seo audit seo audit lahore best seo audit” | “Consultant presenting an SEO audit report to a client” |
When to leave alt text empty
Purely decorative images (background patterns, dividers, icons next to text that already says the same thing) should have an empty alt attribute: alt="". That tells screen readers to skip them. Don’t omit the attribute entirely.
Other image SEO basics
- Descriptive file names (
meta-ads-audit-checklist.png, notIMG_0042.png) - Compressed images in WebP or AVIF
- Width and height set (prevents layout shift)
- Lazy-load images below the fold, but not the main hero image
- Images near related text
Image checks are part of the on-page SEO checklist.