Tips for effective Alt Texts
Your ‘Alt text’ is your alternative text or alternative description. The alternative text has three use cases:
Primary use for alternative texts. The alternative text will show up if your image fails to load. Or if the server times out. Or if the device’s connection to the internet suddenly goes away (i.e. if the user is scrolling through their mail while using the metro). Some mail clients even fail to load the images as a result of default security measures.
Secondary use for alternative texts. Image recognition is an exciting technology, but it is still far from perfect. At this moment in time, describing your image is still the best way to tell a machine what you are showing. The visually impaired use special technology that describes the image to them based on the alternative text you have provided.
Tertiary use for alternative texts. SEO. Your alt text is the perfect excuse to throw a couple of keywords into the mix.
That is why the alternative text has to be:
Do's and don’ts
Do not concentrate on any one of the purposes of your alt text in particular. Instead, try and have all three purposes of alt text in mind when you are creating your copy.
Let’s say you are describing an image of a coffee shop.
If you write your alt text exclusively for the visually impaired, you might be tempted to start your description with ‘ An image of…’ which will do nothing for your SEO.
Instead, to grab the attention of the visually impaired try using text that describes non-visual concepts. In the coffee-shop environment these would fit perfectly: ‘aromatic’, ‘roasted’, ‘tangy’, ‘flavourful’, ‘humid’, ‘fragrant’, or ‘hot’.
Let’s go back to the coffee shop scene for this example.
This is an example of a poor choice of alt text:
‘Coffee shop, café, coffee bar, barista’
Fine, those may be your keywords, but keyword density is old news not just in conventional copy. Go for an organic, optimized description of the image with long-tail keywords. Something like:
‘Local New York coffee shop busy barista serving aromatic coffee’
Your alt text is responsible to bring the message home when the image fails to load. Here, the rule is to observe the balance between keeping it descriptive and keeping It short. If your alt text is about 10 words long, you are good.
Last but not least
Here are several more general rules you might want to stick to:
- Describe the action – use some verbs
- If text is visible, write it down
- If you can see a landmark, tell the location
- If the person is known, tell their name
- Go between 100 and 125 characters