Alt tags

What are Alt Tags?

Alt tags (short for "alternative tags") are HTML attributes used within an <img> tag to provide a text description of the image. They are also known as alt attributes or alt text. The primary purpose of alt tags is to describe the content and function of an image on a webpage. These descriptions are especially important for users who are visually impaired and rely on screen readers to access website content.

For example, an image tag with an alt tag might look like this:

<img src="example.jpg" alt="A person riding a bicycle on a sunny day">


What Do Alt Tags Do?

Alt tags serve several key functions:

1. Accessibility: Alt tags improve accessibility for visually impaired users who use screen readers. The screen reader will read out the alt text to describe the image, helping the user understand the content of the image.
2. SEO (Search Engine Optimization): Alt tags provide search engines with additional information about the content of images, which can help images rank in image search results and improve the overall SEO of a website.
3. Image Fallback: If an image cannot be loaded (due to a broken link or slow connection), the alt text will be displayed in its place, giving users an idea of what the image was supposed to convey.
4. Context and Relevance: Alt tags help provide context for images within the page content, clarifying the image's purpose or relevance to the surrounding text.

Are Alt Tags Important for SEO?

Yes, alt tags are important for SEO. Here’s why:

1. Image Search Rankings: Search engines like Google use alt text to understand the content of an image. This can help your images appear in search engine image results, potentially driving more traffic to your website.
2. Content Relevance: Alt tags help search engines better understand the content of your webpage. Well-written alt tags can contribute to improved rankings for relevant keywords, as search engines take image context into account when indexing content.
3. Accessibility Compliance: Alt tags are important for ensuring that your website complies with accessibility standards such as WCAG (Web Content Accessibility Guidelines). Accessibility is increasingly considered an important ranking factor by search engines like Google.
4. User Experience: If an image fails to load, having meaningful alt text improves user experience by providing context and preventing confusion.

How to Check Alt Tags on a Website

To check the alt tags on a website, you can use several methods:

1. Manually Using Browser Developer Tools:
   • Right-click on an image on a webpage and select "Inspect" or "Inspect Element" in your browser (e.g., Chrome, Firefox).
   • In the HTML section that appears, look for the <img> tag and check the value of the alt attribute.
2. Using Browser Extensions:
   • There are several browser extensions available, such as "Alt Text Tester" for Chrome, that can highlight images on a webpage and display their alt text.
3. SEO Audit Tools:
   • SEO tools like Screaming Frog, Ahrefs, or SEMrush can be used to crawl your website and generate reports that show which images are missing alt tags or have poorly written alt text.
4. Using Accessibility Evaluation Tools:
   • Tools like WAVE (Web Accessibility Evaluation Tool) can analyze your website and highlight any issues with alt text, helping you ensure your site is accessible to all users.

How to Write Alt Tags

Writing effective alt tags requires clarity, accuracy, and relevance. Here are some tips on how to write good alt tags:

1. Be Descriptive and Specific:
   • Clearly describe the image content in a concise manner. For example, instead of writing "Image of dog," a better alt text might be "Golden retriever playing with a ball in the park."
2. Keep It Short and to the Point:
   • Alt text should be brief but descriptive. Aim for about 100 characters or less. Avoid overly lengthy descriptions that may confuse users or screen readers.
3. Include Relevant Keywords (But Don’t Overstuff):
   • Use relevant keywords in your alt tags where appropriate, but avoid keyword stuffing. The alt tag should describe the image naturally and not sound like a list of keywords.
4. Focus on Functionality for Functional Images:
   • For functional images, such as buttons or icons, describe the function they perform rather than their visual appearance. For example, for a search icon, the alt tag should say "Search" rather than "Magnifying glass."
5. Leave Decorative Images Blank:
   • If an image is purely decorative and doesn’t add value to the content, it’s best to leave the alt attribute empty (alt=""). This tells screen readers to skip over the image.

Alt Tags vs Alt Text

The terms "alt tags" and "alt text" are often used interchangeably, but there is a subtle distinction:

• Alt Text: Refers to the actual text description provided within the alt attribute of an image. It is what screen readers read aloud and what search engines use to understand the image content.
• Alt Tags: Technically, "alt tags" is an incorrect term, as "tag" refers to an element in HTML. The correct term is "alt attribute," which is the HTML attribute used within the <img> tag to define the alt text.

In essence, alt text is the content (the description) and alt attribute (sometimes mistakenly called alt tags) is the HTML attribute that contains the alt text within the image tag. Despite the technical difference, many people use "alt tags" and "alt text" to mean the same thing.

Example of correct usage in HTML:

<img src="golden-retriever.jpg" alt="Golden retriever playing with a ball in the park">


In summary, well-written alt tags (or alt text) play an important role in accessibility, user experience, and SEO, helping search engines and users better understand the visual content on your website.