Image Descriptions and Accessibility in General on Tumblr for New Users
What are Image Descriptions
Image Descriptions are text following a picture explaining what’s in that picture. They are primarily for blind/visually impaired people with screen readers and visually impaired people who can read text but have issues with pictures.
They also help people who have trouble:
focusing on/understanding a picture
reading text on images (ex low contrast, weird fonts, etc)
getting images to load
Without image descriptions posts are not accessible to many people, so if you can it's best to include a description or alt text every time you post an image.
Alt text vs image descriptions
Image descriptions are written in the body of the post itself, and have some kind of text before and after, to explain that what's coming up. They typically begin short and concise, but can expand to more detail.
Alt text is added to the image itself, and is what is read by screen-readers (which will otherwise just say "image"). There is no need to add any explanation before the description so you can just say "a description of the image". Alt text can only be added by the original poster, by clicking on the three dots in the bottom right corner of the image and clicking 'update image description.' It is typically short and concise.
On tumblr, alt text is currently available on web by clicking on the alt button (or via new xkit - accesskit - move alt text to captions below image). On mobile, alt text is available in some versions of the app through clicking on the alt text button. Image descriptions are visible on all posts, although if you put them under a read-more, that makes them less accessible. (Thanks to @911described for helping with this section)
How to Make Image Descriptions
Awhile ago I made this general guide. I learned from examples, so here are descriptions made by a bunch of different people. I've also made templates for a lot of common images you'll see on Tumblr.
Other Concerns
Gradient or all caps text make most screen readers read out the word one letter at a time. In addition, these plus text that is bold/italicized/underlined, in colors other than black, or in weird/fancy fonts are difficult for many people to read.
How Filtering Works
You can filter out both words/phrases and tags in the filtering section under the general section in the settings. When filtering out words from a post, it will look at both the text of the post/reblog chain and at the url of op and the rebloggers. When filtering out tags it will look at the tags of the specific post on your dash, and at the tags of the original post.
Tagging for Common Triggers
Don't sensor trigger warnings (for example don't tag suic!de) because then people who have them filtered will still see it.
Tagging for Flashing Lights
If you post a gif or video in a post that flashes, you should tag it with something like "flashing lights" and Not "tw epilepsy" because if any of the tags in the original post contains the world epilepsy it will show up in the epilepsy tag, which is dangerous. Check out this post from @photosensitive-despair for more info about tagging photosensitive content.
Tagging for Unreality vs Misinfo
Things that could trigger delusions/psychotic episodes/etc should be tagged with unreality. This includes:
content that has existential themes related to reality/things not existing (example: a philosophy such as solipsism, do not look up the term if unreality stuff is triggering for you)
extremely surreal content(example: sometimes content such as weirdcore/dreamcore aesthetics can fall under this umbrella but again this is very subjective)
content that reinforces or encourages common delusions(example: that one "im living in your walls" meme)
Things like rp blogs and fake/edited tweets should not be tagged with unreality, unless they contain triggering content. Consider tags like "fiction" or "misinfo." See this post for more info.
Edit:
Addition from @mindflamer
You can look through the reblogs of a post to see if someone's already written a description. There is a button to see just comments vs. comments + tags which makes it easier. Scroll through looking for brackets [], ID, or Image Description. This is great to do if you can't write your own IDs for whatever reason, so that you can at least spread the version of the post that's described if there is one.
If you're not able to write IDs consistently, some is better than none. Don't let the perfect be the enemy of the good. You can use the tag #undescribed to make it easy for those who need them to filter out those posts. Similarly, if you primarily tag triggers but can't for certain posts, you can use a separate tag on that to be filtered such as #untagged.
Please, if I forgot something, sound off in the notes and I'll update this post with it
