User alternate text wherever we have pictures, icons, thumbnails which also helps in SEO and works as image placeholders. Alternatives text is used as a replacement for an image, whenever the image cannot be seen. This can happen, for example, when someone:
- uses a screen reader (e.g. a visually impaired person)
- uses a text-only browser (e.g. browsing from a mobile phone)
- uses a graphical browser with images turned off
- has not yet downloaded the image
- browses results from a Web search
- fails to download the image because of a network problem
- copies an extract from a Web page into a word processor.
Alternative text is also used for other purposes. For example, Google’s image search uses it to help return appropriate images. Finally, good choice of alternative text and captions makes life easier for people, who are viewing the source of an article, either when editing it, or in a diff, or in Wikipedia’s internal search.
