Alt text helps people who may not be able to see an image for various reasons by providing a textual description which accompanies the image. A significant guide to alt text, why it is important, and how to achieve good alt text is here: https://webaim.org/techniques/alttext/
On the desktop web client, when writing a post, you can add an image by clicking on the paperclip icon on the bottom menu on the left.
! No description added
over your image.Apply
and that’s it! You can then publish your toot normally.edit
or No description added
Apply
(you will note the No description added
text disappears)Add image description
Save
, then publish as normal.Set Caption
from the menuOK
and publish your toot.On the web client (desktop/mobile):
App Settings
in the menuCompose box
, enable Show confirmation dialog before sending toots lacking media descriptions
While this functionality is available in the web client (regardless of accessing via a mobile browser or desktop), it is unlikely to be present in your mobile App. As of writing it is not available in Tusky or the official Mastodon App for Android.
You can follow @PleaseCaption@botsin.space to remind you to add alt-text in case you forget.