Marginal Schema Markup

WordPress plugin from Marginal that outputs JSON-LD schema markup in <head>:

• Global JSON-LD (e.g. Organization, LocalBusiness, WebSite) on every page on the site.
• Page-specific JSON-LD on individual Pages, output at the very end of <head>.

All output is wrapped in `` block. If you paste several blocks, they are merged into a list.

JSON-LD on a single page

Open a page under Pages. Below the editor there is a Schema markup (JSON-LD) box. Paste the JSON-LD and update the page.

Only administrators can see and change the box. Editors can still edit the page itself, but they can't change or delete its JSON-LD.

In both places the field shows live whether the JSON is valid, and Format JSON tidies up the indentation. "Valid" always means that the JSON-LD can actually be output. Invalid JSON is still saved, so nothing gets lost, but it is not output on the site. You get a warning instead, and the error is written to the log.

The limit is 200 KB per field. Anything larger is rejected with a clear message, and the previous version is kept.

The log

Settings → Schema Markup → Log shows errors such as:

• invalid JSON-LD on a page, with a link to the page
• a theme/template that never calls wp_head(), or a theme/plugin that removes the plugin's output from <head>, so the JSON-LD (global or for a page) is not output. HEAD requests from uptime monitors are ignored, so they never produce false errors.
• failed update checks against GitHub

Identical errors are merged into one line (with a count). The log keeps the latest 100 lines.

Updates

New versions show up under Plugins and Dashboard → Updates like any other plugin. WordPress checks automatically about twice a day, and the plugin caches GitHub's response for 6 hours. Use Settings → Schema Markup → Updates → Check for updates now to check immediately. Automatic updates can be turned on per site from the plugin list.

Security

The plugin is built so that nobody can use it as a way into the site: