Level: Basic
Alt text is often written as an afterthought, but genuinely useful alt text requires actually considering what a screen reader user needs to understand from the image.
Describe What's Genuinely Relevant, Not Just What's Visible
Good alt text focuses on the information or purpose the image conveys in context, not an exhaustive literal description of everything visible in it.
Purely Decorative Images Should Be Marked Appropriately
An image that adds no informational content should be marked so screen readers skip over it, rather than reading out an irrelevant description.
Avoid Redundant Phrases Like "Image Of"
A screen reader already announces that an element is an image, making phrases like "image of" or "picture of" unnecessary and slightly cumbersome to listen to.
Next step: Use the Get Source Code of Webpage to review your current image alt text in the underlying code to check how genuinely descriptive and relevant it actually is.