Free tool · JSON-LD
Fill in a form, get schema markup that passes.
This schema markup generator writes JSON-LD for eight types, from Organization and BlogPosting to FAQPage, Event and Product, and checks the form before it writes, from required fields and full URLs to ISO dates and event times with their offset. It never writes ratings or reviews. It runs in your browser with the same rules Heddle's gates hold every built page to.
Checked as you type
Fill in the form, or load the example, and problems show here.
<script type="application/ld+json">
{
"@context": "https://schema.org",
"@type": "Organization"
}
</script>
How the tool decides
Required fields come from Google's structured data documentation for each rich result, made stricter where Heddle's gates are. An article's author is a Person with a page, and both dates are ISO 8601. An event's start and end are local times with their offset, because a bare time gets read as UTC and moves an evening event to the next day. Ratings and reviews are left out, since Google treats invented review markup as spam.
Which type to use
Organization goes once, on the home page, so engines know who publishes the site. BlogPosting goes on each post, FAQPage on a page whose questions and answers are visible, BreadcrumbList on every page below the home page, Event on each session's own page, and Product on a page that sells one thing with a price. LocalBusiness is only for an address customers can visit or that you serve from, since Google checks it against Business Profile.
Markup describes what's on the page. If a question or a price is in the JSON-LD and not on the page, it's a mismatch Google can act on. Our page on schema markup covers what it does and doesn't do for rankings.
Checks to run after you paste it
The generator checks what you typed, not your page. It can't tell whether the image URL loads, whether the FAQ is visible, or whether the page already carries a second node for the same thing. Run the result through Google's Rich Results Test before you ship it.
On the sites Heddle runs, those are checked on every build. The surface gate holds the markup each kind of page needs, and the events gate holds every Event node.
Sources
- developers.google.com/search/docs/appearance/structured-data/search-gallery
- developers.google.com/search/docs/appearance/structured-data/event
- developers.google.com/search/docs/appearance/structured-data/article
- schema.org
Each was read on October 11, 2026.
Questions
Where do I paste the markup?
Inside the page's head, or anywhere in the body; Google reads JSON-LD in either. One script tag per node is fine.
Why won't it add star ratings?
Because a form can't know your ratings are real, and Google treats self-serving or invented review markup as spam. Add Review or AggregateRating only from reviews shown on the page itself.
Does anything I type get stored?
No. Everything runs in your browser; nothing you enter is sent anywhere.
Work with us
Have the agents keep it true.
A file you write once goes stale the next time the site changes. Heddle writes llms.txt, robots.txt and the markup on every deploy, and its gates fail the build when one of them is wrong. Tell us about your site and we'll show you what they would catch.
On the call, for your site
- The searches your buyers makeMeasured, with how many people make each one
- Where you show up, and where you don'tOn Google and in ChatGPT's answers
- The agents' first monthThe pages, fixes and links they would start with