Which Open Graph tags are required for a page object?

Definition: The Open Graph protocol requires four basic properties for every page object: og:title, og:type, og:image and og:url. You place them as metadata in the page <head> with a property attribute and a content value.

Key facts

• The Open Graph protocol specification calls og:title, og:type, og:image and og:url the four required properties for every page.
• og:title gives the object title as it should appear in the graph, while og:type identifies the object type.
• og:image takes an image URL that represents the object.
• og:url takes the canonical object URL and serves as its permanent identifier in the graph.
• The protocol says that the selected og:type can make other properties necessary for that type.

What are the four required properties?

The protocol calls these fields its basic metadata. og:title is the title of the object as it should appear in the graph. og:type describes the object type, with video.movie given as an example. The protocol says that the chosen type can require additional properties.

og:image is an image URL representing the object. og:url is the canonical URL of the object and is used as its permanent identifier in the graph. The URL should identify the page object represented by the other three values.

How do you add them to HTML?

The protocol says to add additional <meta> tags in the page <head>. Its examples use property for each Open Graph property and content for its value. This follows the RDFa model. The W3C's RDFa Core 1.1 recommendation describes property as a way to represent predicates and content as a way to represent literal objects.

<head>
  <meta property="og:title" content="Page title" />
  <meta property="og:type" content="website" />
  <meta property="og:image" content="https://example.com/image.jpg" />
  <meta property="og:url" content="https://example.com/page" />
</head>

The four properties form one basic set. A page can also have optional structured properties. For example, the protocol defines og:image:alt as a description of the image and says that a page specifying og:image should specify og:image:alt.

What value should og:type have?

The value identifies the object type. The protocol lists website as a global type and says that a non-marked-up webpage should be treated as og:type website. It also states that the website type has no additional properties beyond the basic ones.

Other types can have their own requirements. The protocol uses video.movie in its basic example and places type-specific properties in the relevant type section. A page that uses a more specific type therefore needs to check that type's documented fields.

Related terms

• Canonical URL
• Structured data
• Semantic HTML
• JSON-LD

FAQ

Do all four tags belong in the page head?

Yes. The Open Graph specification says to place the additional meta tags in the page <head> and presents the four properties in that markup.

Is og:type="website" enough for a website page?

For the protocol's website type, the specification says that no additional properties are required beyond the basic ones. A different type can have additional requirements.

Is og:image:alt one of the four required properties?

No. It is an optional structured property of og:image. The protocol recommends it when a page specifies og:image and defines it as an image description rather than a caption.

Sources

1. Open Graph protocol, "The Open Graph protocol", undated
2. W3C, "RDFa Core 1.1 - Third Edition", 17 March 2015

---

Check how a page reads to answer engines. Open the GEO score analyzer