A review snippet is the rating excerpt Google may show under a search result, with stars, a score and sometimes the reviewer or review count. It is powered by Review markup for a single critic review or AggregateRating markup for an average of many. Only certain item types are eligible, and Google's review guidelines restrict who can mark up what.
Supported item types
Google lists the types that can carry review snippets, including Book, Course, Event, LocalBusiness, Movie, Product, Recipe and SoftwareApplication, among others. Some of these are limited further: LocalBusiness and Organization ratings about the site owner are excluded under the self-serving reviews rule. Check the documentation for the current list.
Single reviews
A Review needs itemReviewed, author, and a reviewRating with ratingValue. It suits editorial reviews, such as a blog post reviewing a tool. The author must be a real person or organization, and the review must be visible on the page.
{
"@context": "https://schema.org",
"@type": "Review",
"itemReviewed": { "@type": "SoftwareApplication", "name": "Quernstack",
"applicationCategory": "DeveloperApplication", "operatingSystem": "Web" },
"author": { "@type": "Person", "name": "Marta Ilves" },
"reviewRating": { "@type": "Rating", "ratingValue": "4", "bestRating": "5" }
}Pros and cons
For editorial product reviews, Google supports positiveNotes and negativeNotes properties to list pros and cons, which may appear in the snippet. They apply to reviews of products, not to merchants' own product pages listing their own advantages.
Example
Reviewing a third-party tool
An agency blog at Copperlode publishes an in-depth review of a project management app. The article includes Review markup with the reviewer as author, a 4 out of 5 rating and pros and cons lists matching the bullet points in the article.
Common mistakes
Reviews about yourself
Marking up reviews of your own company on your own site as Organization or LocalBusiness reviews will not produce stars.
Hidden or invented reviews
Reviews must be visible and genuine. Fabricated reviews breach Google's spam policies.
Questions
For eligible item types such as a product or software app, yes, if they are genuine and visible. For reviews of your own organization, Google will not show stars.
