A review snippet is a rich result in which a search engine displays a star rating, a rating value and often a review count or reviewer name beneath a page’s title, based on Review or AggregateRating markup found on the page. In structured data, it is one of the most recognizable enhancements, because the stars make a result stand out visually on the results page.
The snippet is generated from Schema.org vocabulary, usually written in JSON-LD, that describes either a single critic review or an aggregate of many user ratings for a specific item. Valid markup makes a page eligible for the snippet; whether the stars actually appear remains the search engine’s decision.
How a review snippet is generated
The search engine reads the structured data during crawling and rendering, validates it against its feature requirements and checks that the rating matches content visible on the page. If the markup qualifies and the page is judged suitable, the result can be shown with stars. The visual element is computed from the numeric rating relative to the rating scale, which defaults to 1 to 5.
Two markup patterns feed the snippet. A Review describes one evaluation by a named author, such as an editorial product test. An AggregateRating summarizes many ratings, such as customer scores on a product page. Both are attached to the reviewed item, for example a Product or Recipe, through the review or aggregateRating property, or they name it through itemReviewed.
The table below lists the properties that matter most and their role.
| Property | Used in | Purpose |
|---|---|---|
| ratingValue | Rating and AggregateRating | The numeric score shown as stars |
| bestRating and worstRating | Rating and AggregateRating | Scale limits, default 5 and 1 |
| ratingCount or reviewCount | AggregateRating | Number of ratings or reviews, at least one required |
| author | Review | Person or organization that wrote the review |
| itemReviewed | Review and AggregateRating | The specific item being evaluated |
Eligible item types and policy restrictions
Review snippets are supported only for specific item types, and the reviewed thing must be one of them. Common eligible types include Product, Recipe, Book, Course, Movie, SoftwareApplication, Event and LocalBusiness, among others listed in the search engine’s documentation.
The most important restriction concerns self-serving reviews. When a business marks up reviews about itself on its own site, for example a LocalBusiness or Organization showing its own customer ratings, the stars are not eligible for display. Reviews of products a merchant sells remain eligible, because the reviewed item is the product rather than the merchant.
| Situation | Eligible for stars | Reason |
|---|---|---|
| Customer ratings on a product page | Yes | Product is a supported item type |
| Editorial review of a laptop | Yes | Third-party evaluation of a product |
| Restaurant rating its own service | No | Self-serving review of the business |
| Recipe with user ratings | Yes | Recipe is a supported item type |
| Ratings hidden from the page | No | Markup must reflect visible content |
Further requirements apply to individual reviews. The author must be a real person or organization with a valid name, not a phrase such as a discount offer, and the review should concern a specific item, not a broad category or a list of products. Pages that review several items usually mark up each review separately rather than combining them into one rating.
Review snippet compared with related structured data
Review markup is rarely used alone. It typically nests inside another schema type, and its visual result overlaps with other rich results in structured data.
| Markup or feature | Relation | What it adds |
|---|---|---|
| Product schema | Common parent of review data | Price, availability and identifiers |
| Rich results | Umbrella category | Review snippet is one rich result type |
| Organization schema | Restricted parent for own reviews | Company details, not star eligibility |
| JSON-LD | Preferred syntax | Markup separate from the visible HTML |
| Microdata or RDFa | Alternative syntaxes | Markup embedded in HTML attributes |
Implementing review markup correctly
Correct implementation follows a few principles. The rating must come from real reviews visible on the page, the scale must be stated when it differs from 1 to 5, and the review count must match the number shown to visitors. Aggregate ratings should be collected by the site itself or a legitimate review platform, not copied from other sites.
Testing happens in two steps. The Rich Results Test shows whether the page is eligible for the review snippet and lists missing or invalid fields, while the Schema Markup Validator checks general Schema.org correctness. After deployment, the review snippets report in Search Console tracks valid items and errors across the site.
Dynamic ratings are a frequent implementation detail. When ratings update continuously, the markup should be generated from the same data source as the visible rating, so the two never drift apart.
Placement also matters. Review data belongs on the page dedicated to the reviewed item, not on category listings where many products appear together. On a category page, ratings of individual products are better shown visually without markup, because no single item is the main subject of the page.
Mistakes and risks
Misused review markup is one of the more common triggers of a structured data manual action, which removes rich result eligibility until the issue is fixed.
- Marking up invented or curated ratings: displaying only favorable reviews or fabricated scores violates guidelines.
- Site-wide aggregate ratings: placing a company rating on every page misattributes it to unrelated content.
- Copying third-party reviews: ratings gathered on other platforms should not be marked up as the page’s own.
- Expecting guaranteed stars: even valid markup may not show, because display depends on the search engine’s assessment.
Beyond policy, there is a click-through trade-off. Stars attract attention, but a visibly low rating can discourage clicks, so the snippet rewards genuinely well-rated items rather than masking weak ones.
In plain words
A review snippet is the row of stars you sometimes see under a search result, together with a score such as 4.6 and the number of reviews. It gives searchers a quick sense of what other people thought before they even click.
Websites make this possible by adding a small, hidden description of their ratings in a format search engines understand. The search engine then decides whether to show the stars. Honest ratings that visitors can actually see on the page are the condition for it.
A real-world example
An online cookware shop collects customer ratings on its product pages but shows plain search results without stars. The developers add JSON-LD Product markup with an AggregateRating to each product page, generated from the same database that displays the visible average score and the number of reviews.
The Rich Results Test confirms eligibility, and the review snippets report in Search Console soon lists several thousand valid items. Stars begin to appear for many product searches. The team does not add a company-wide rating to the home page, because that would be a self-serving review. The result is more visible product listings without any risk of a manual action.