The “itemprop” attribute was specified, but the element is not a property of any item.

Microdata is an HTML specification that lets you embed machine-readable data into your content using three main attributes: itemscope, itemtype, and itemprop. The itemscope attribute creates a new item (a group of name-value pairs), itemtype specifies what kind of thing the item is (using a vocabulary URL like Schema.org), and itemprop defines individual properties within that item. These attributes work together — itemprop only makes sense in the context of an itemscope.

When the validator encounters an itemprop attribute on an element that isn’t a descendant of any element with itemscope, it has no way to associate that property with an item. The property is essentially orphaned. This is a problem for several reasons:

• Search engines can’t use the data. Structured data consumers like Google, Bing, and other crawlers rely on the itemscope/itemprop hierarchy to understand your content. An orphaned itemprop is ignored or misinterpreted.
• Standards compliance. The WHATWG HTML living standard requires that an element with itemprop must be a property of an item — meaning it must have an ancestor with itemscope, or be explicitly referenced via the itemref attribute on an itemscope element.
• Maintenance issues. Orphaned itemprop attributes suggest that surrounding markup was refactored and the microdata structure was accidentally broken.

The most common causes of this error are:

1. Missing itemscope — You added itemprop attributes but forgot to define the containing item with itemscope.
2. Moved elements — An element with itemprop was moved outside of its original itemscope container during a refactor.
3. Copy-paste errors — You copied a snippet that included itemprop but not the parent itemscope.

To fix the issue, either wrap the itemprop elements inside an itemscope container, use itemref to associate distant properties with an item, or remove the itemprop attribute if structured data is not intended.

Examples

Incorrect: itemprop without itemscope

This triggers the validation error because there is no itemscope ancestor:

<div>
  <p>My name is <span itemprop="name">Liza</span>.</p>
</div>

Correct: itemprop inside an itemscope container

Adding itemscope (and optionally itemtype) to an ancestor element fixes the issue:

<div itemscope itemtype="https://schema.org/Person">
  <p>My name is <span itemprop="name">Liza</span>.</p>
</div>

Correct: nested items with their own scope

When an item contains a sub-item, the nested item needs its own itemscope:

<div itemscope itemtype="https://schema.org/Person">
  <p itemprop="name">Liza</p>
  <div itemprop="address" itemscope itemtype="https://schema.org/PostalAddress">
    <span itemprop="addressLocality">Portland</span>,
    <span itemprop="addressRegion">OR</span>
  </div>
</div>

Correct: using itemref for properties outside the scope

If you can’t restructure your HTML to nest itemprop inside itemscope, use itemref to reference elements by their id:

<div itemscope itemtype="https://schema.org/Person" itemref="user-name"></div>

<p id="user-name">
  My name is <span itemprop="name">Liza</span>.
</p>

In this case, the itemprop="name" element is not a descendant of the itemscope element, but the itemref="user-name" attribute explicitly pulls the referenced element’s tree into the item, making it valid.

Incorrect: scope broken after refactoring

A common real-world scenario where the error appears after restructuring:

<div itemscope itemtype="https://schema.org/Product">
  <span itemprop="name">Widget</span>
</div>

<!-- This was moved out of the div above -->

<span itemprop="price">9.99</span>

Fix this by either moving the element back inside the itemscope container, using itemref, or removing the orphaned itemprop.

Learn more:

WHATWG Spec

Learn more about microdata

→