Validation

Schema Pro → Tools lists every active schema that is missing a property Google requires. An Error means the markup will not qualify for rich results until it is fixed; a Warning means it works but could be stronger.

Every page, not one sample#

Each schema is checked on every published post, page and product it covers, not only on one example. A Recipe schema on all your recipes is checked on each one, so the recipes without a photo are found even when the rest have one.

The Page Checks panel under Tools → Validation shows, for each active schema, how many of the pages it covers are missing a required property, for example "Missing a required property on 37 of 412 pages", which property is missing ("Image is missing on 37 pages"), and the first 50 of those pages, each linked to its editor, with how many more there are. It also says when every page was last checked, or how far a check has got: "Checking: 120 of 412 pages so far".

The Problems list on Tools and on the Dashboard, and the Schemas list, use the same numbers. When all that is missing is something each post fills in for itself, such as a featured image, the line is a Warning: the schema is right and those posts need the image. It is an Error when pages are missing a property the schema itself should give, or their markup cannot be used. Page Checks, the Dashboard's Problems card and the post editor use the same two tones, and say which in words at the start of each line: Warning: in amber, Error: in red, so neither the colour nor a screen reader is needed to tell them apart. In Page Checks and the post editor a warning is what a post fills in for itself. The Dashboard's Problems card also uses Warning: for advice about the schema itself, such as a rating given without a count, a salary without a currency or an address that does not look like one; those are fixed in the schema, and the line says what to change. In the post editor, the box turns red when any line in it is an error. The sentence "Every active schema has the properties Google requires" only appears once a whole check has finished and no page fails.

When the check runs:

• In the background, in WordPress's scheduled tasks. Each run checks pages for about ten seconds and the next run carries on where it stopped, so a large shop takes several runs. A visitor's page view never runs it. If a run is still going when a new check starts, it stops at the next page, so two checks never count the same pages twice or lose one. With no active schema there is nothing to check, and a check ends at once.
• Again from the start whenever you save, activate or delete a schema, save the site identity, change the settings for other schema plugins or WooCommerce, or import settings; and once a week otherwise. The daily check also starts it again when an SEO plugin is switched on or off. While a new check runs, the pages it has not reached yet keep showing what the last check found. After an update that changes what Google requires, a property no longer required stops being counted at once; one newly required is found when the daily check starts the next check under the new rules.
• Straight away when you press Check every page now. It checks for a few seconds while you wait: if every page is done in that time the answer is on the screen it comes back to, and otherwise the rest carries on in the background.
• For one post, whenever that post is saved: set the missing image on a post, update it, and the numbers change as soon as the save has finished. The post is checked at the end of the save, once its image, price and everything else are written, so posts and products created by an importer, WooCommerce's product import or the REST API are checked with their image and price. This includes a product whose price or image a shop manager changes through WooCommerce, and a post saved from the front of your site, for example a forum topic, which adds that one check to the visitor's save.
• For the posts that use a featured image, when it is set, changed or taken off without the post being saved, or deleted from the Media Library.
• A save of many posts at once, such as a bulk edit or one step of an import, checks as many as it can in about two seconds and leaves the rest to a background check.

What it checks, and what it does not:

• Only the properties Google requires for that type count (see What Google requires below). A property that fills itself from each post and is empty on one post counts as missing on that post. Advisory warnings, such as a web address that does not look like one or a rating without a count, are never counted, and neither is a property Google only recommends. They are not worked out during the check either: the reason a variable product keeps its price range, which means reading its variations, is given on Problems and in the schema editor, where it is shown, and the check of every page does not read any variation to find it.
• Course schemas have no rich result of their own on a page, so an empty title there is not counted. Web Page, FAQ, How-to, Audio, Podcast Episode, Vehicle Listing, Service and Custom JSON-LD schemas have nothing Google requires, so only markup that cannot be built at all is counted: an About page without a featured image is not a page to fix.
• Markup the page does not carry is not checked: a type you have left to your SEO plugin, or Product while your products keep WooCommerce's own markup. Tools says so for that schema.
• Archives, search results and the blog index are not checked, and neither are the page chosen as your posts page and the WooCommerce shop page, which show a list rather than the page itself.
• A page whose markup cannot be built because of an error, often another plugin's filter that expects a visitor's page, is listed as one that could not be checked, rather than as missing something.

The results are kept in the plugin's own database table, one row per page and schema, and nothing is added to your posts. On a multisite network each site checks its own pages.

The most common gap is a missing image. Google requires one for a recipe, a movie and a product in a merchant listing, and a forum post needs one here because its markup carries no text or video. For an article, and most other types, an image is recommended rather than required, so it is not counted. Setting a featured image on the post usually resolves it, because the image field fills automatically.

What Google requires#

A property is marked with a star in the editor, and counted when it is empty, only where Google's documentation for that type lists it as required. A local business's address is the one exception to the star: Google requires an address as a whole, and any one part of it will do, so its fields carry no star and the check names Address only when every part is empty. These follow Google's pages as they read on 23 September 2026:

Types with no Google page of their own (FAQ, How-to, Podcast Episode, Service, Web Page, Audio, Vehicle Listing and Custom JSON-LD) have nothing marked required. A few of Google's requirements are not checked here yet: a course's description, a dataset's description, an event's address, and a software application's rating or review.

A field that only applies to some answers is only checked for those: an online event is not asked for a venue. A job posting with a salary but no salary currency gets a warning, because a salary figure means nothing without one.

An FAQ, How-to, Recipe or other type made of one page's content gets a warning when that content is typed into the schema and its rules cover more than one page, because every one of those pages would carry the same questions or ingredients.