Getting your images online (for good SEO) in a few important steps:
First of all NAME the file with “image-description-keyword-
Now upload the image to your server. And make a short, clear, image description for the ALT (image) tag. This will help to explain to a blind user what image is displaying and it will provide text in the event that your image does not appear on your site.
Now you are ready for the TITLE (image) tag which is generally visible when one mouses over an image. Here you may wish to make a slightly shorter description and AVOID AT ALL TIMES stuffing keywords into this text.
An SEO practice that can be of use is to make a LINK on an image to FURTHER INFORMATION about the topic (instead of simply having the image, when clicked, appear larger). In this case, you might INDICATE in your TITLE TAG that if one clicks on the image that you are taken to a PDF file or another source.
Note: It is wise to have at least one image per blog post to allow for social media sharing.
A BIT MORE FROM OTHER SOURCES:
Can I Duplicate Title and Alt Text? Via raventools.com
If you have a large page with a lot of images, what keywords you use in your image alt and title fields could make a small difference in your rankings.
But keyword stuffing is still keyword stuffing.
Rules of thumb:
- Provide explicit details about your image and include keywords, but use different keywords for the title and the alt tag.
- Ideally, an image title should follow the same rule of a regular post title or article headline — it should be relevant, catchy and concise.
- Sometimes we all run out of time and simply use the same text in both the image title and the alt text. It’s not the end of the world. More: https://raventools.com/blog/alt-title-text-optimized-images/
Alternative text serves several functions – via webaim.org
It is read by screen readers in place of images allowing the content and function of the image to be accessible to those with visual or certain cognitive disabilities.
It is displayed in place of the image in browsers if the image file is not loaded or when the user has chosen not to view images.
It provides a semantic meaning and description to images which can be read by search engines or be used to later determine the content of the image from page context alone. More: https://webaim.org/techniques/alttext/#basics
See: W3C’s Easy Checks for manual accessibility checking.