Images play a vital role in modern websites.
They help businesses:
- capture attention
- explain concepts
- strengthen branding
- improve engagement
- support storytelling
However, search engines and assistive technologies cannot “see” images the way people can.
This is where alt text becomes important.
Alt text helps describe images to search engines and screen readers, making content more accessible while also supporting search engine optimisation (SEO).
Despite being one of the simplest website improvements available, alt text is often overlooked.
What Is Alt Text?
Alt text, short for alternative text, is a written description added to an image within a website’s code.
Its primary purpose is to provide context when an image cannot be viewed directly.
Alt text helps:
- screen readers describe images to visually impaired users
- search engines understand image content
- improve accessibility
- support image SEO
Think of alt text as a short explanation that communicates the purpose of an image.
Why Alt Text Matters
Alt text serves two important functions:
Accessibility
Alt text helps users who rely on screen readers understand visual content.
Without alt text, important information contained within images may be inaccessible to some visitors.
SEO
Search engines use alt text to understand image content and context.
Properly optimised images can appear in image search results and contribute to overall page relevance.
Good alt text supports both users and search engines.
Accessibility Comes First
Although many people focus on SEO, accessibility should always be the primary purpose of alt text.
Millions of people rely on assistive technologies when browsing the internet.
When screen readers encounter images, alt text helps communicate:
- what the image shows
- why it matters
- how it relates to surrounding content
Accessible design creates better experiences for all users.
How Search Engines Use Alt Text
Search engines cannot interpret images perfectly on their own.
Alt text provides valuable context.
For example, an image file named:
image123.jpg
tells search engines almost nothing.
However, alt text such as:
“Graphic designer creating a responsive website layout on a laptop”
provides useful context about the image and page content.
This additional information can help search engines understand relevance more effectively.
Writing Effective Alt Text
Good alt text should be:
- descriptive
- concise
- accurate
- relevant
The goal is to explain the image naturally.
Good Example
“Freelance graphic designer presenting logo concepts to a client.”
Poor Example
“Image.”
or
“Graphic design graphic designer logo design branding logo business logo designer.”
The second example attempts keyword stuffing and creates a poor user experience.
Avoid Keyword Stuffing
One of the most common SEO mistakes is overloading alt text with keywords.
Search engines have become increasingly sophisticated.
Instead of stuffing keywords, focus on writing descriptions that sound natural and useful.
Good alt text improves understanding.
Poor alt text often creates confusion.
Decorative Images Don’t Always Need Alt Text
Not every image requires a detailed description.
Purely decorative visuals that add no informational value may use empty alt attributes.
Examples include:
- background graphics
- decorative shapes
- purely aesthetic design elements
This prevents screen readers from reading unnecessary information.
Alt Text for Business Websites
Business websites often use images to support branding and services.
Useful alt text may describe:
- team members
- services
- products
- portfolio projects
- locations
- events
The description should explain the image in a way that supports user understanding.
Alt Text and E-Commerce
For online stores, alt text becomes especially important.
Product images should clearly describe:
- the item
- colour
- style
- key features
This helps both accessibility and image search visibility.
Good product image descriptions improve user experience significantly.
Image SEO Beyond Alt Text
While alt text is important, image SEO involves several factors.
Other best practices include:
- descriptive file names
- image compression
- responsive image sizing
- modern image formats
- structured data when relevant
Alt text works best as part of a broader image optimisation strategy.
Common Alt Text Mistakes
Many websites make simple alt text errors.
Common mistakes include:
- leaving alt text blank unnecessarily
- keyword stuffing
- writing descriptions that are too vague
- repeating surrounding text word-for-word
- adding unnecessary phrases like “image of”
Alt text should be clear and purposeful.
Alt Text and User Experience
Accessible websites often create better experiences overall.
Accessibility improvements frequently benefit:
- mobile users
- slow internet connections
- assistive technology users
- search engines
Alt text contributes to a more inclusive and user-friendly website experience.
Alt Text and Modern SEO
Modern SEO focuses heavily on user experience and content quality.
Alt text supports both.
While alt text alone will not dramatically increase rankings, it contributes to:
- better accessibility
- improved image relevance
- stronger website quality signals
Small improvements often add up over time.
Why Businesses Should Prioritise Alt Text
Many businesses spend significant time creating visual content but neglect image optimisation.
Adding alt text:
- takes very little time
- improves accessibility
- supports SEO
- enhances user experience
It’s one of the simplest website improvements available.
Final Thoughts
Alt text plays an important role in both accessibility and SEO.
By providing meaningful image descriptions, businesses can help users understand visual content while improving search engine visibility.
Good alt text is clear, concise, and user-focused.
As websites continue prioritising accessibility and user experience, optimising images properly becomes an increasingly valuable part of modern web design and SEO strategy.
