Free Schema Markup Generator: JSON-LD from URL or Text

Schema markup is a machine-readable statement about what a page already contains. If the page is an article, the markup can identify its headline, author, publication date, images, and publisher. If it is a product page, the graph can identify the product, brand, offer, currency, availability, and genuine aggregate rating. The important phrase is already contains.

JSON-LD does not turn thin content into a strong page. It does not create an author who is missing from the byline, make an old price current, or convert a collection page into one specific product. A search engine is meant to compare the structured statement with the visible page. When the two disagree, the code is not a helpful clarification; it is a misleading claim.

That is why this generator starts with two clear paths and ends with code. Choose AI assistance when you want the tool to recommend a profile: a public URL supplies visible text, metadata, canonical links, and existing structured data, while pasted page copy becomes the evidence set before publication. Choose a schema type when you already know the intended entity and want to follow its guided formula without AI. The path changes how facts enter the draft, but a deterministic compiler always owns the final structure.

This distinction matters at scale. Across the websites in SEOmator's January–July 2026 audit panel, 64.8% had at least one critical failure in the Structured Data category, while 47.9% had no structured data on eligible pages. Missing markup is common, but adding more code is not the only answer. The code must be accurate, maintained, and tied to the page users can see.

Three questions are often collapsed into one green check:

1. Does the JSON parse? A JSON parser can answer this. It catches missing commas, broken quotes, trailing characters, and invalid object structure.
2. Does the vocabulary make sense in Schema.org? The Schema.org Validator checks types, properties, expected value shapes, and relationships in the open vocabulary.
3. Is the page eligible for a current Google search feature? Google's Rich Results Test and feature documentation apply a smaller, changing set of search-specific requirements.

A block can pass the first two checks and have no general Google rich-result treatment. Organization and WebSite markup can still help describe and connect entities, but that is not the same product as a Product rich result. HowTo remains valid Schema.org even though it is not a current general rich-result surface. FAQPage is valid vocabulary, but Google limits its visible treatment to a narrow class of authoritative health and government sites.

The reverse also matters. Passing Google's test creates eligibility, not an entitlement. Search systems decide whether to show a feature for each query and page. Page quality, policy compliance, visible-content parity, and the rest of the search result all still matter.

The generator therefore reports errors, warnings, and notices separately. An error blocks a safe production copy. A warning points at missing recommended fields or a policy-sensitive pattern. A notice may simply explain that a valid type does not map to a current general feature.

Schema is clearest when the primary node answers the same question as the page.

An article page should normally lead with Article, BlogPosting, or NewsArticle. A single product detail page can lead with Product and nest or connect its Offer. A specific event needs Event. A job detail page needs JobPosting. A company contact or about page may need Organization or LocalBusiness. BreadcrumbList describes the visible navigation path, but it is usually supporting markup rather than the page's main entity.

More types are not automatically better. Adding Organization to every URL can create dozens of disconnected copies of the same company. Adding Product to a category page can imply that the whole collection is one purchasable item. Adding FAQPage because two headings happen to end with question marks does not make the page an FAQ.

The v1 catalog deliberately supports twelve maintained profiles rather than the whole Schema.org vocabulary. Each profile records required and recommended properties, known value shapes, Google feature status, high-risk fields, and the date the guidance was reviewed. That narrower surface is easier to test and much harder to let go stale.

When a page genuinely contains several entities, connect them. An Article can refer to an author and publisher. A Product can contain an Offer. A WebSite can identify its publisher. Stable identifiers let those references point to one entity rather than repeating loose copies.

@id is not a database identifier assigned by Schema.org. It is a URL-shaped name you control. A predictable pattern makes the entity reusable across pages and releases:

{
  "@context": "https://schema.org",
  "@graph": [
    {
      "@type": "Organization",
      "@id": "https://example.com/about#organization",
      "name": "Example Company",
      "url": "https://example.com/"
    }
  ]
}

The fragment after # does not need to resolve to a separate document. Its job is to distinguish the organization from the page URL while keeping the identifier anchored to a canonical domain. A related node can then use { "@id": "https://example.com/about#organization" } rather than copying the organization's name, logo, URL, and profiles again.

Consistency is more useful than cleverness. Choose #organization, #person, #product, #software, #video, or another stable fragment and reuse it. Avoid timestamps, random IDs, staging domains, and URLs that redirect differently by locale or device.

The generator requires a canonical URL before it allows production copy because stable identifiers and relative URLs need a base. You can still prepare a text-mode draft before publication, but supplying the intended canonical URL is the point where the graph becomes deployable.

Some structured properties can mislead users or trigger policy problems even when their syntax is perfect. They receive a stricter treatment in this tool:

• Ratings and review counts must describe genuine ratings visible on the page and must appear as a pair.
• Price, currency, availability, and condition must match the current offer a visitor can access.
• Publication, modification, event, upload, and job dates cannot be guessed from today's date or a crawl timestamp.
• Addresses, coordinates, opening hours, and telephone numbers must describe the entity on the page, not a guessed headquarters.
• Job salaries and valid-through dates must be real and current.

AI suggestions cannot confirm these values for you. A model can notice a visible price and cite its excerpt, but only the publisher knows whether that price is current, whether tax is included, and whether the offer applies to the canonical product. The checkbox is deliberately friction: it creates a moment to compare the field with the live business fact.

Unknown is a valid state. The compiler omits empty optional properties instead of writing null, an empty string, today's date, or a placeholder such as YOUR_LOGO_URL. This keeps the draft smaller and makes missing editorial work visible.

Many pages already contain markup from a theme, SEO plugin, commerce platform, tag manager, or previous developer. A new generator should not pretend the page is empty.

The URL flow inventories JSON-LD, Microdata, and RDFa before suggesting a primary profile. It summarizes existing types and identifiers so you can see whether Product, Organization, BreadcrumbList, or another node is already present. The manual validator accepts an existing JSON-LD block and checks parsing, missing context or type, duplicate identifiers, review and rating risk, and stale assumptions about FAQPage or HowTo.

The right fix is often to edit the source that already owns the entity. If a commerce platform renders the Product and Offer, adding a second hand-written Product block can produce conflicting prices or identifiers on the next release. If a site-wide plugin owns Organization, link the page entity to its stable @id instead of repeating it.

Check the rendered HTML, not only the source file you edited. Client-side plugins can add or replace JSON-LD after page load, and tag managers can create duplicates that do not exist in a template repository. Google's test and a browser's DOM view are useful here because they inspect what the page actually delivers.

Copying the snippet is the start of implementation, not its final check.

Place the JSON-LD script in the page head or body where your framework or CMS renders it reliably. Escape script-closing content when user-authored text can enter the JSON. Keep the output on the canonical page that visibly supports it. Then open the deployed URL in the Schema.org Validator and Google's Rich Results Test.

Revalidate when the page changes. Commerce markup drifts when price and stock systems change. Article dates drift when a template starts using a build timestamp as dateModified. JobPosting becomes misleading when an expired role remains live. Event status and attendance mode change when a venue or schedule changes. Organization data drifts during rebrands and migrations.

Build ownership into the release process: decide whether a CMS plugin, framework component, product feed, or server template is authoritative for each entity. One owner per node prevents two systems from racing to publish different facts.

Finally, monitor what search engines see, but do not measure schema success only by whether a decorated result appears. The first success condition is accurate machine-readable content that stays aligned with the page. Eligibility is a useful outcome. A visible rich result is a search engine's decision, not a promise any generator can make.