PostEaseThe short answer
An accessible post can be understood by people who cannot see the image, cannot hear the video, use a screen reader, or read slowly. Five habits cover most of it: write alt text for every image, add captions to every video, capitalise each word in hashtags (#SmallBusinessTips), use emoji sparingly and never in place of words, and make links say where they go. These habits also help everyone watching without sound or scanning quickly.
Platforms give you the tools. X accepts alt text of up to 1,000 characters per image, Pinterest up to 500, and Bluesky has an alt field on every image. YouTube creates automatic captions with speech recognition, but says they may misrepresent what was said and that creators should always review and edit them.
Alt text by platform
What each platform documents:
| Platform | Alt text | Where it is documented |
|---|---|---|
| X | Up to 1,000 characters per image | X API media metadata |
| Up to 500 characters per Pin | Pinterest Pin specs | |
| Bluesky | An alt field on every image | The app.bsky.embed.images lexicon |
| YouTube | Captions and subtitles for video | YouTube Help on automatic captions |
How to write alt text
Describe what matters in the image for this post, in a sentence or two:
- Say what the image shows and why it is there: “A sourdough loaf, cut open to show an airy crumb.”
- Include any text in the image, word for word, since a screen reader cannot read pictures of text.
- Skip “image of” or “picture of”; screen readers already announce it as an image.
- Keep it short for simple images and longer for charts or infographics, where the data matters.
- For a carousel, write alt text for each slide, not only the first.
Captions on video
Captions let deaf and hard-of-hearing viewers follow a video, and help everyone watching on mute. Use the platform’s automatic captions as a start, then correct them: YouTube warns that automatic captions might misrepresent the spoken content because of mispronunciations, accents, dialects or background noise. Put key words on screen too, and do not rely on audio alone to make the point.
Hashtags, emoji and text
Capitalise each word in a hashtag, called camel case, so screen readers pronounce it as words: #SocialMediaTips rather than #socialmediatips. Put hashtags at the end of a caption rather than in the middle of a sentence. Use emoji to add, not replace, meaning, and avoid long strings of them, since each one is read aloud by name. Avoid fancy Unicode “fonts”, which screen readers often read as gibberish.
Colour, contrast and links
Text on images needs strong contrast with the background, and meaning should never rely on colour alone. Make links descriptive: “Book a cut on our site” says more than “click here”. Keep important information in the caption as well as the image, so it reaches people who cannot see the picture.
A checklist for every post
Run through this before scheduling:
| Element | Do | Avoid |
|---|---|---|
| Images | Alt text that says what matters, including any text in the image | Leaving it blank, or “image of” |
| Video | Corrected captions, and key words on screen | Relying on sound alone |
| Hashtags | Camel case, at the end of the caption | All lower case, in the middle of sentences |
| Emoji | A few, adding meaning | Long strings, or emoji in place of words |
| Text on images | Strong contrast, large type | Meaning shown by colour alone |
| Links | Words that say where the link goes | “Click here” |
Why it matters
Accessible posts reach more people and lose fewer. They work for screen-reader users, for viewers with the sound off, for people reading in a second language, and for anyone scrolling fast.
Questions
How long should alt text be?
A sentence or two for most images, longer for charts. Platforms set maximums: X allows 1,000 characters and Pinterest 500.
Are YouTube’s automatic captions good enough?
Use them as a start. YouTube says they may misrepresent speech and that creators should always review and edit them.
Why should hashtags be in camel case?
Capitalising each word (#SmallBusinessTips) lets screen readers pronounce the words correctly and makes the tag easier for everyone to read.
Do emoji affect accessibility?
Yes. Screen readers read each emoji’s name aloud, so long strings are tiring to hear. Use a few, and never in place of words.
Sources
- X, Media metadata, X API documentation, checked October 2026.
- Pinterest, Review Pin specs, checked October 2026.
- Bluesky, app.bsky.embed.images lexicon, checked October 2026.
- YouTube, Use automatic captioning, checked October 2026.