What are image alt tags – how do you create them and why are they important?

What are image alt tags and how can they be used as part of a successful on-page SEO strategy?

In this short introduction we’ll:

  • Define what an alt tag is without confusing jargon
  • Explain the role they play in improving SEO
  • Outline alt tag best practices you can use now
  • When and when not to use them

What is an alt tag?

Sometimes an image on your website will fail to load. This leaves an unexplained space on the page – which might confuse users. Alt tags solve this problem by appearing in place of the missing picture.

What do image alt tags contain? A concise description that tells a story for visually impaired users who rely on screen readers to access your blog, landing page, or other content resource.

Do alt tags help SEO?

Alt tags help SEO. You can, for example, insert short or long tail keywords into descriptions where applicable – which will help search engines understand the theme of your content so it can be shown to the right audience.

What else are image alt tags used for? Their most important function is to provide your visitors with a superb user experience. 

If customers can’t understand your content they won’t engage and will drop out of the buying journey out of sheer frustration.

How do you write an alt tag?

Alt tags are written into the HTML code of your website. Although Google Bots will be able to index your text visitors won’t see the caption unless the corresponding image fails to load.

How to add alt tags to a website depends on the Content Management System (CMS). But let’s use WordPress as an example.

To add an alt tag image in WordPress:

  • Upload the image into your page
  • In the backend click the text tab
  • Look for the image map

Not sure how to find this? Here’s an example of an image map:

As you can see, there’s an attribute called ‘alt.’ Simply type your text between the quotation marks.

Click Update to complete the process and add your descriptive content to the page.

Good versus bad alt tags

How hard is it to write good image alt tags? There is certainly an art to it. The trick is to be descriptive without turning the process into a keyword stuffing exercise – which could lead to Google-imposed penalties.

Let’s use the below photo as an example…


Bad example of alt text: ‘young boy dressed in blue measuring marketing, marketing metrics, SEO’

True, it’s a young boy. And, yes, he’s dressed in blue. But the sentence is bloated with too many keywords and phrases – which would confuse the reader or listener. In fact, it’s not even a proper sentence.

Good example of alt text: ‘A small boy dressed in a blue blazer with a tape measure while standing in front a house.’

This paints a clear picture, allowing visitors to fill in the gap in your story. It would have been nice to weave in a key term but doing so would have disrupted the user experience.

Alt tag best practices

What are image alt tag strategies you can use to write more effectively? Here are some tips to get you started.

Use keywords sparingly

Keywords should only be inserted if relevant. An image of a stressed man sitting in front of a typewriter could be captioned ‘copywriter trying to overcome writers block in a busy office.’

The alt tag, in this case, would paint an accurate visual image of your protagonist’s dilemma and search engines understand your content.

Content is King typed on retro typewriter

Keep alt tags short

125-characters is the recommended length for an alt tag. Remember, it’s a caption and should be concise. Apart from that screen-readers cut off after this point, so the listener won’t understand your description.

Spellcheck captions

Apart from harming your brand credibility, misspelt words sound strange when read out loud to visually impaired visitors. These errors will also confound the search engines, limiting organic reach.

Not all images need alt tags

If the image:

  • already contains text or is explained by a heading
  • is a button or logo that might be hard to explain
  • doesn’t add important context to the page
  • performs a purely aesthetic function

…then no alt tag is necessary.

In most other cases alt text is probably required. 

Need a helping hand with your marketing?

From alt tags to rebranding strategies the Boss Digital team has you covered. Book your free consultation now.

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