Tips for Writing Alternative Text:
Be Descriptive: The purpose of alt text is to communicate the content and function of an image. Therefore, be as descriptive as possible within a reasonable character limit (typically 125 characters).
Keep It Concise: While being descriptive, also strive for conciseness. The alt text should not be overly verbose or lengthy. Aim to deliver maximum information in the fewest words possible.
Avoid Redundancy: Don't begin alt text with "image of" or "picture of," etc. Assistive technologies already announce the image, so it's better to jump directly into the description.
Don't Forget Function: If an image has a specific function (e.g., it's a button to submit a form), make sure to include this in the alt text.
Context Is Key: The same image may require different alt text in different contexts. Consider why the image is there and what information the user would need to have an experience equivalent to that of a sighted user.
Use Proper Punctuation: To make the alt text easier to understand, use proper punctuation. This helps assistive technologies read the text properly.
Ignore Decorative Images: If an image is purely decorative and doesn't provide any information, it's often best to use an empty alt attribute (alt=""). This way, screen readers will skip over it.
Consider the Surrounding Text: If the image is described adequately in the surrounding text, there may be no need to duplicate this information in the alt text. In this case, an empty alt attribute may be used.
Describe Links: If an image is used as a link, the alt text should describe the destination of the link.
Complex Images: For complex images like charts or infographics, you might need a longer description. This can be provided in the main text or on a linked page. The alt text should give a high-level summary of the image.
No Need for Style Descriptions: Unless it's directly pertinent to the page content, avoid describing colors, styles, or other design elements of the image.

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