Images make web pages more engaging—but search engines and screen readers can’t “see” them. That’s where alt text comes in.
Alt text (alternative text) describes an image in HTML so search engines and assistive technologies understand what the image represents. When used correctly, alt text improves accessibility, SEO, and user experience.
In this guide, you’ll learn the best practices for writing effective alt text, along with real examples you can apply immediately.
What Is Alt Text?
Alt text is a short description added to an image’s HTML tag.
Example:
<img src=”golden-retriever-puppy.jpg” alt=”Golden retriever puppy playing with a tennis ball”>
This description serves two main purposes:
- Accessibility: Screen readers read the alt text aloud for visually impaired users.
- SEO: Search engines use alt text to understand image content and context.
If the image fails to load, the alt text appears instead.
Why Alt Text Matters for SEO
Search engines rely heavily on text signals to interpret visual content.
Well-written alt text can help:
- Improve image search rankings
- Provide context for surrounding page content
- Strengthen keyword relevance
- Improve overall accessibility compliance
Google has repeatedly emphasized that helpful alt text improves both usability and search visibility.
1. Describe the Image Clearly and Specifically
The best alt text describes what’s actually in the image.
Good alt text should answer:
“What would someone need to know if they couldn’t see this image?”
Example
Image: A laptop displaying a Google Analytics dashboard
Bad alt text:
alt=”analytics”
Good alt text:
alt=”Google Analytics dashboard showing website traffic statistics on a laptop”
The second example gives both context and meaning.
2. Keep Alt Text Short and Natural
Alt text should usually stay under 125 characters. Screen readers often stop reading after that.
Write naturally—like you’re describing the image to someone next to you.
Example
Bad alt text:
alt=”picture of a beautiful large modern office workspace with computers desks chairs and lighting”
Better alt text:
alt=”Modern office workspace with desks, computers, and overhead lighting”
Clear. Concise. Helpful.
3. Avoid Keyword Stuffing
Adding too many keywords makes alt text look spammy and harms user experience.
Bad example
alt=”SEO marketing strategy SEO tools digital marketing SEO campaign SEO agency”
Better
alt=”SEO specialist analyzing website traffic data on a laptop”
Use natural language, not keyword lists.
4. Don’t Start With “Image of” or “Picture of”
Screen readers already announce the element as an image.
Avoid phrases like:
- “Image of”
- “Picture of”
- “Photo of”
Bad
alt=”Image of a chocolate cake”
Better
alt=”Chocolate cake with strawberries and whipped cream”
Jump straight to the description.
5. Include Important Context When Relevant
Sometimes the purpose of the image matters more than the visual details.
Example: A blog post about email marketing showing a graph.
Instead of describing every detail:
alt=”Line graph showing email open rates increasing from 15% to 28%”
This explains the key message of the image.
6. Use Empty Alt Text for Decorative Images
Not every image needs a description.
If an image is purely decorative, use empty alt text:
alt=””
This tells screen readers to skip the image, preventing unnecessary noise.
Common decorative images include:
- Background graphics
- Design separators
- Icons with nearby text labels
7. Write Unique Alt Text for Each Image
Avoid repeating the same alt text across multiple images.
Each image should provide unique context.
Example in a recipe blog:
Bad:
- alt=”pasta recipe”
Better:
- alt=”Ingredients for creamy garlic pasta on a kitchen counter”
- alt=”Cooking garlic in olive oil in a skillet”
- alt=”Finished creamy garlic pasta served in a bowl”
Unique descriptions help both users and search engines understand the content.
8. Match Alt Text With Page Content
Alt text should support the topic of the page.
Example: A blog about “home workout routines.”
Better alt text:
alt=”Woman performing bodyweight squats in a living room workout”
This strengthens topical relevance for SEO.
Practical Alt Text Examples
| Image Type | Good Alt Text Example |
| Product photo | Black leather backpack with silver zipper on a white background |
| Chart | Bar chart comparing monthly website traffic from January to June |
| Blog tutorial | WordPress dashboard showing the add new post page |
| Food blog | Fresh avocado toast topped with cherry tomatoes and sesame seeds |
Each description explains exactly what the user needs to know.
Alt Text Best Practices Checklist
Before publishing, ask yourself:
- Does the alt text describe the image clearly?
- Is it concise (under ~125 characters)?
- Does it avoid keyword stuffing?
- Does it skip phrases like “image of”?
- Is it relevant to the page topic?
- Is it unique for each image?
If the answer is yes, your alt text is likely strong.
FAQ: Alt Text Best Practices
What is the ideal length for alt text?
Most accessibility experts recommend under 125 characters. The goal is clarity, not length.
Does alt text directly improve SEO?
Alt text is a small but important ranking signal, particularly for Google Image Search and overall content relevance.
Should every image have alt text?
Not necessarily. Decorative images should use empty alt text (alt=””) so screen readers ignore them.
Can alt text include keywords?
Yes—but only when they fit naturally within the image description.
What happens if you don’t use alt text?
Without alt text:
- Screen reader users lose context
- Images may rank worse in image search
- Accessibility compliance may suffer
Final Thoughts
Alt text might seem like a small detail, but it plays a big role in SEO, accessibility, and user experience.
The best alt text is clear, concise, and helpful. Focus on describing what matters, keep it natural, and align it with the page’s topic.
When done correctly, alt text helps search engines understand your content and ensures everyone can access it.
