Specificity is key Alt text should form a clear mental image of what the content is by describing the image as specifically as possible.
Keyword integration Incorporate relevant keywords from research in alt text for better search relevance1. Use keywords to reflect the language people use when talking about and searching for an image while providing a strong description of image content.
Avoid overstuffing Keyword stuffing can detract from user experience and search engine perception, and is burdensome to people who use screen readers and will not impress search engines.
Decorative images Use CSS for purely decorative images, not HTML. If an image truly doesn’t convey any meaning/value and is just there for design purposes, also known as decorative images, it should live within the CSS of your site, rather than your HTML.
Write alt text that briefly but thoroughly describes an image while being a great help, not a boring burden, to people using screen readers1
Alt text length does not have any official guidelines from Google, so it is an element that calls for common sense3. Write alt text that briefly, but thoroughly, describes an image3. Alt text is a confirmed ranking factor for image search only5. Google uses alt text, along with computer vision algorithms and the contents of the page, to understand the subject matter of the image5. Improper use of alt text can harm your website.
Here are key points regarding alt tags:
Ranking Factor Alt text is a confirmed ranking factor for image search. For general organic search, Google treats alt text like any other text on the page.
Accessibility Alt text is a helpful accessibility tool for screen readers5.Length Google has no official guidelines on alt text length, so use common sense.
Keywords Alt text offers another opportunity to include your target keyword.
Relevance Focus on creating useful, information-rich content that uses keywords appropriately and is in the context of the page.
Traffic Alt text can help images rank better in Google Images, leading to more traffic4
Yoast SEO’s alt tag check aligns with Google’s guidelines by emphasizing descriptive, information-rich alt text that uses keywords appropriately and is in context with the page content1. Here’s a breakdown of the key differences and similarities:
Emphasis on descriptive text: Both Yoast SEO and Google stress the importance of having descriptive alt text to help search engines understand the image’s content and its relevance to the surrounding text.
Keyword usage: Yoast SEO checks if your focus keyphrase is present in the alt text to increase your chances of ranking in image searches14. Google also recommends including keywords if they are useful and relevant to the image.
Against keyword stuffing: Both Yoast SEO and Google advise against keyword stuffing in alt tags, as it can lead to a negative user experience and may cause your site to be seen as spam1. Yoast SEO has a specific check to prevent over-optimization; if the keyphrase is in more than 70% of your images’ alt tags, it will flag this as an issue.
Relevance and context: Yoast SEO encourages creating alt text that is contextually relevant to the content of the page1. Google also emphasizes the importance of alt text being related to the surrounding content.
Accessibility: By prompting you to add alt text, Yoast SEO improves website accessibility, providing screen readers and search engine users with a textual description of the image1. This aligns with Google’s aim to make web content accessible to everyone.
In summary, Yoast SEO’s alt tag check reinforces Google’s guidelines by promoting descriptive, relevant, and contextually appropriate alt text while discouraging keyword stuffing14. The plugin offers practical feedback and scoring to help users optimize their alt tags for both SEO and accessibility1
