What is alt text?
Short for alternative text, alt text refers to the written descriptions of images on a website or email. It is the text you see whenever an image fails to load on a website you are using or an email you are reading.
If you wish to learn more about this topic, check out the FAQ section below:
Question #1: Does alt text affect accessibility?
Absolutely! It improves the accessibility of your web pages and emails by allowing screen readers to describe your images to visually impaired users. Without alt text, screen readers would not even know that there are images on your web pages and emails.
Question #2: Does it affect SEO?
Yes! Alt text also affects SEO.
You see, while it is only visible to you when the images on a website or email fail to load, it is always visible to search engines—and they use it, along with the written content on your website, to gauge your site’s relevance to the keywords your customers use to search for the things they need online.
This means that if you take the time to write proper alt text for the images on your website, you will have a much better chance of ranking higher on search engine results pages (SERPs).
But what exactly does it mean? Well, that is exactly what we will talk about in the next section.
Question #3: How do I write good alt text?
You must follow six simple rules:
First, keep your description short and clear. Just talk about what you see without making any assumptions. Think how you would describe what you see briefly over the phone.
As a general rule, it is best to keep your descriptions under 125 characters because that is the limit for most screen readers.
Second, avoid starting with ‘image of…’ Not only is it unnecessary, it would also sound extremely repetitive when read by a screen reader—especially if a page has a lot of images.
Describing the kind of image on screen, however, is perfectly fine. This means that you can use terms such as:
- Illustration
- Headshot
- Painting
- Screenshot
- Graph
Third, do not overuse keywords. Only use your top keywords when they are actually relevant to the image you are describing. Otherwise, Google might penalise you for keyword stuffing by ranking you lower on its SERPs.
Fourth, if the image contains text, it is a good idea to mention it in your alt text. The only time you should avoid doing so is when doing so would make you repeat yourself, as in:
- Men’s restroom sign that says ‘men’
- Welcome mat that says ‘welcome’
- Buffet sign that says ‘buffet’
Fifth, avoid repeating yourself. As a general rule, if your alt text would simply repeat something that is already written somewhere else on the page, then it is not necessary.
Examples would be:
- For an image that already has a caption
- For an image of a book that you are selling when the page header already says the title of the book
- Alt text for an image of yoga classes when the header of the page is already ‘Yoga Classes’
The sixth and final reason is that you should not write alt text for decorative images. Examples of this would be brand graphics and page dividers.
As a general rule, if an image does not add context to the content of the page, then there is no need to write alt text for it. Doing so might end up confusing both search engines and people using screen readers.