- How I Write Alt-Text
‘Alt-text’ is short for alternative text, and is used to convey the substance of visual content as text. It is important for people with visual disabilities, though is beneficial for a wide range of people. It is useful for low-speed connections where an image might not load, for searching for an image, for SEO/AIO/GEO, for cases where a link to an image is broken, for understanding context, and for a variety of other gains.
Here are some notes on how I write alt-text:
I don’t start my description with ‘image of’, ‘picture of’, or similar superfluous details, unless the medium is relevant. For example, I will note if it is a logo, a graphic, an illustration, or similar.
I always end alt-text with a full stop to avoid further document content being read as if a continuation of the alt-text.
I try to keep my alt-text at one to two sentences, though will expand to more if necessary. In the majority of cases, detail becomes excessive beyond two sentences.
I ask the question, ‘What would I tell someone if I was explaining this to them over the phone?’. This lets me identify what I must include for context and what the most important parts of the image are.
I don’t use AI to write my alt-text. If I have included an image for a reason, then no LLM can precisely tell what that reason is without me telling them, and if I’m telling them then I’m more or less writing the alt-text anyway. I also dislike outsourcing my writing to LLMs, with writing of alt-text being no exception.
I will not write alt-text if it is not relevant or needed. Nothing is gained from explaining a flavour image on a website. It is there for a bit of visual space filling, not for its value or substance. In this case it should be noted that the alt text has purposefully been left blank and hasn’t just been omitted. In HTML, this is done by writing
alt="".
Ultimately, I just try to convey with alt-text what I’m trying to convey with the image. That is the goal.