1. Define what people need to understand

Before technical settings, state the post’s main idea. Short structure, direct sentences and explained terms support people reading quickly, learning the language or experiencing cognitive barriers. Put essential information before a long group of hashtags.

Avoid all-capital paragraphs and long emoji sequences that can become tiring with a screen reader. Capitalise each word in a multiword hashtag to make its boundaries clearer.

2. Write useful alternative text

Alternative text communicates the image’s purpose in context. Describe the information that would be missing without the image; you rarely need to start with “image of”. A decorative image may need no description if the platform supports that choice.

A dense infographic usually needs a summary in the post or a link to a structured version. Do not put essential information only inside an image.

3. Caption video and offer a transcript

Add synchronised captions for speech and sounds needed for meaning. Automatic captions are a starting point, not a final check: review names, technical terms and punctuation.

For information-rich video, provide a transcript or linked summary. Verbally describe important visual information that dialogue does not already communicate.

4. Protect contrast, readability and control

Use sufficient contrast, readable text size and a position that interface buttons will not cover. Do not encode a category only by colour; add a label, shape or pattern.

Avoid rapid flashing and unnecessary motion. Where possible, let people pause, reread or use a static version.

5. Test before and after publishing

Watch video without sound, zoom the screen, review alternative text and check link wording. On mobile, make sure captions are not clipped. Periodically ask people who use assistive technology for feedback.

Accessibility features differ between platforms. Keep your alternative text and captions with production files so they remain available for authorised reposting.

Your checklist

  • The main idea is understandable in the post text.
  • Every informative image has a contextual description.
  • Speech is captioned and the captions were reviewed.
  • The content works without sound, colour distinction and at zoom.

Frequently asked questions

What belongs in alternative text?

Describe what the image contributes here: relevant people or objects, action, setting and essential visible text. Be concise without omitting useful information.

Are automatic captions enough?

They can speed up the process but need review. Names, accents, numbers and specialist terms often produce errors.

Must I describe every decorative detail?

No. Exhaustive description can hide the main point. Describe the function and useful elements in context.

Sources & method

This guide turns institutional recommendations into practical steps. Features and remedies vary by country, account and service version.

Editorial responsibility: Alexis R., World Web Certified. Suggest a correction.