Schema.dev vs SEOMarkup Schema Inspector (2026): which should you pick?

Pick Schema.dev if

• Fits if you mark up a handful of pages and can paste JSON-LD into your CMS
• Works for checking what structured data a page already has

Look elsewhere if

• Skip it if you don't use Chrome, as it's a Chrome extension only
• Too light for whole sites, as markup is built page by page and the Deployer isn't out
• Watch out: the extension's latest version, 0.80.1, is from March 2025, and the site's newest blog posts are from 2020
• Tight if you want the Schema Tester or its API, which sit in a beta behind a sign-up
• Not for you if you want the markup added for you, as you copy and paste it yourself

Pick SEOMarkup Schema Inspector if

• Fits if you debug structured data before a release and want to read it as a tree
• Works for seeing which schema types a competitor's page uses

Look elsewhere if

• Skip it if the page uses Microdata or RDFa, which are only flagged, not shown
• Too light for validation on its own, as that means opening Google's or Schema.org's tester
• Not for you if you use Firefox or Safari, as it runs in Chromium browsers only
• Watch out: the developer hasn't identified itself as a trader, so EU consumer rights don't apply

Schema.dev

• It works only as a Chrome extension; there is no plugin that adds the markup to your site for you.
• The Schema Tester and its API are a beta behind a sign-up, and the Schema Deployer is still marked as coming soon.
• The extension's latest version, 0.80.1, dates from March 2025, and the site's newest blog posts are from 2020.
• Markup is built page by page; templates that cover many pages at once are planned for the unreleased Deployer.

SEOMarkup Schema Inspector

• Microdata and RDFa are only detected and labelled, not displayed; full parsing covers JSON-LD.
• Validation happens by opening Google's Rich Results Test or validator.schema.org, not inside the extension.
• It is listed for Chrome, and the vendor says it works in other Chromium-based browsers; there is no Firefox or Safari version named.
• The Chrome Web Store notes the developer has not identified itself as a trader, so EU consumer rights do not apply.

Schema.dev

Point-and-click builder

A step-by-step form for each schema type, filled by clicking elements on the page or typing, with text transformations and custom values.

Dozens of schema types

Covers the types Google supports for rich results and more; the March 2025 update added vehicle listing markup.

Required and recommended fields

Guides you through the required, recommended and optional properties for each type, so less schema knowledge is needed.

Detection and testing

Finds structured data already on a page and tests generated markup, showing errors and warnings.

JSON-LD output

Produces formatted JSON-LD that you copy and paste into the page or your CMS.

SEOMarkup Schema Inspector

JSON-LD tree view

Parses every JSON-LD script block, splits @graph arrays into separate schemas and shows each as an expandable tree.

Full-text search

Search for a property name, value or URL across all schemas on the page, with next and previous match buttons.

Copy, download, validate

Copy a schema as raw JSON or a ready-to-paste script tag, download it as a .json file, or open the page in Google's Rich Results Test or validator.schema.org.

Parse error banners

When a JSON-LD block is malformed, a banner shows which block broke and why.

Microdata and RDFa detection

Flags when a page also uses Microdata or RDFa, though only JSON-LD is shown in full.

Schema.org links

Click any schema type to open its documentation on Schema.org.

Schema.dev

• Free$0

  The Schema Builder extension for Chrome with built-in testing, plus the Schema Tester beta.

SEOMarkup Schema Inspector

• Free$0

  Every feature of the extension, free from the Chrome Web Store with no account.