Where the image appears, there should be a black bar on the bottom of the image with the text “Add description”. Click “Add description”.
A larger version of the image appears. At the bottom, there is a text box that reads “Describe this photo for the visually impaired.”
Type in that box your image description and then click “Apply”.
Note 1: Though used by some members of the community, to many, the term “visually impaired” is can be considered inappropriate, particularly without the use of “people” along with it.
Note 2: Twitter has a character limit for the description.
Steps to add image descriptions on Facebook posts:
Add an image.
Where you include a caption for the post, include the planned caption. Underneath the caption, provide the image description. The image description may be placed in brackets or without, but regardless, should start with “Image description:”.
Note: When posting links on Facebook that include thumbnails, it is good practice to describe the image provided as well.
Example: [Image description for link thumbnail: provide your description here]