The structured data types that actually change your listing.

The test that matters

A validator answers one question: is this well-formed and does it satisfy the required fields. That is worth knowing and it is not the question you care about. The question you care about is whether adding it changes anything, and the honest answer for most types is no.

Start from the right expectation. Structured data is not a ranking factor, and Google has said so plainly. What it can buy is eligibility for a different-looking result, and an entity a machine can resolve without guessing. Both are worth having. Neither is a position.

The types that earn a visible result

This is the short list. If a type is not here, adding it will not change how your result looks, whatever the validator says.

BreadcrumbList is the one nearly everybody should have and plenty skip. It costs almost nothing, applies to every page on a structured site, and replaces an ugly URL line with a readable path. It is the highest ratio of benefit to effort on the list.

The types that do invisible work worth doing

These produce no rich result and are still the most important markup on most sites, because they answer who published this and what this business is. That question used to be answered by the knowledge panel alone. Now it is also what an assistant reads when it decides whether you are the same entity as a similarly named firm.

The failure mode here is not absence, it is contradiction. Three separate blocks declaring three slightly different organisations, a LocalBusiness address that does not match the Business Profile, a Person on one page and an Organization on another with no relationship between them. Consolidating that into one graph with stable @id values is unglamorous and it is the part that pays.

The types that validate and earn nothing

These still appear in guides, still pass every validator, and still ship on a large share of sites. They do nothing.

FAQPage is the instructive one, because the markup did not break. It kept validating exactly as before while the result it existed to earn was withdrawn from almost everyone. We removed it from this site rather than maintain it, on the reasoning that code with no remaining benefit is a liability with a maintenance cost, not a neutral.

Getting it wrong costs more than skipping it

Markup that contradicts the visible page is worse than no markup. A price in JSON-LD that does not match the price on the page, availability that says in stock when the page says otherwise, a rating with no visible reviews behind it: these are the cases where a manual action is genuinely on the table, and they are far more common than missing markup.

The rule is boring and it holds. Mark up what is on the page, as it is on the page. If it is not visible to a visitor, it does not belong in the structured data.

Where to start

For most sites the whole job is three types. Organization or Person once, sitewide, with a stable @id everything else references. BreadcrumbList on every page that sits in a hierarchy. Then whichever single type from the first table matches what you actually sell.

That is it. The schema markup generator here builds valid JSON-LD for the six types most sites need and flags the required fields you have left empty, and it runs entirely in your browser with nothing uploaded.