Alt text is a short written description of an image, read aloud by screen readers and shown if the image fails to load. For galleries it does double duty: it makes your website accessible to blind and low-vision visitors, and it gives search engines the text they need to understand and rank your artwork images. Every artwork image on your site should have it.
Keep alt text to roughly 125 characters or fewer. Many screen readers cut off around there. Describe what is visually important in one tight phrase. If a work needs a fuller description, put that in a caption or a long description on the page and keep the alt attribute concise.
Describe what is actually depicted, then the medium and, for a gallery, the artist and title. Do not start with 'image of' or 'photo of'. Screen readers already announce it as an image. A good pattern is: subject, medium, palette. For example, 'Empty domestic interior, abstract oil painting in warm ochre and rust.'
Yes. Alt text is one of the main signals search engines use to understand an image, so descriptive alt text with the artist, title and medium helps your artwork surface in Google Images and image-rich results. Write it for a human first (accurate, natural description) and the SEO benefit follows. Avoid stuffing keywords.
Yes. The tool is free to use in your browser with no signup required. Nothing is installed, and you can run as many calculations as you need for planning. Confirm critical figures with product data or a licensed professional before construction.