Schema Markup Validator

Why this is not optional

Malformed JSON-LD is discarded silently. No warning, no partial credit — a single misplaced comma and the entire block is ignored. You get zero benefit and no indication anything is wrong.

That is the whole argument. Ten seconds of validation protects the highest-value change you can make to a page.

How to use it

Paste a URL or the raw code block. It parses the structured data and lists errors and warnings by type. Also run Google's Rich Results Test if you specifically want to know whether a page qualifies for an enhanced listing — the two answer different questions.

The errors you will actually hit

• Trailing commas. Most common by a distance.
• Unescaped quotes inside a description or answer text.
• Missing required properties — Article without headline, Product without name.
• @id references pointing at nothing, usually after copying a @graph between sites.

Verdict

Bookmark it. Use it every time. There is no reason not to.

Commercial disclosure. No link in this directory earns us a commission. If that ever changes, the link will be marked (commercial link), carry rel="sponsored", and this note will say so. What we write does not depend on it: nothing here is a paid placement, the order is not for sale, we review tools that pay us nothing, and we say plainly when a tool is better than ours or when you should spend nothing at all. If that ever stops being true, this directory is worthless and so is the rest of the site.

On pricing. We describe what a tool is for, not what it charges. Prices move, free tiers get withdrawn or introduced, plans get renamed, and what you pay differs by region and currency. Anything we wrote about cost could be wrong by the time you read it, so treat it as a rough shape and check the vendor's own pricing page before you buy. Spotted something out of date? Tell us and we will fix it.