# Schema Preview

> See, validate & score schema.org structured data (JSON-LD, Microdata & RDFa) on any page. Spot SEO gaps, errors, and Google rich-result eligibility, with a live search-result preview. Read-only and 100% private.

Canonical page: [https://chrome-stats.com/d/schema-preview](https://chrome-stats.com/d/schema-preview)

## Overview

- **ID:** `schema-preview`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** Damian
- **Category:** web-development
- **Daily users:** 6
- **Version:** 1.0.0
- **Last updated:** 2026-06-21
- **First published:** 2026-06-18
- **Size:** 107 KB
- **Data as of:** 2026-09-09
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/schema-preview/)
- **Website:** [https://ddcode.cloud](https://ddcode.cloud/)

## Description

Schema Preview reveals the structured data behind any web page, checks it against best-practice rules, and shows exactly what's missing for rich results — no copying markup into an online tester.

<strong>What it does</strong>
  - Detects JSON-LD, Microdata, and RDFa automatically, with a live count on the toolbar badge
  - Parses arrays and @graph, and resolves @id references between nodes
  - Completeness score (0–100) per schema, with required/recommended/optional coverage
  - Validation errors and warnings naming the exact missing fields
  - Google rich-result eligibility checks tied to Google's field requirements
  - Search-result (SERP) preview with stars and price
  - OpenGraph / Twitter Card / meta-tag overview
  - Reports JSON-LD syntax errors instead of failing silently
  - Deep links to <a href="https://prod.outgoing.prod.webservices.mozgcp.net/v1/47254c4864a718c5ef2029189988e062fe24d974d99588b0ea7c831bce8b0a57/http%3A//schema.org" rel="nofollow">schema.org</a> and Google Search docs
  - Validates 47 common <a href="https://prod.outgoing.prod.webservices.mozgcp.net/v1/47254c4864a718c5ef2029189988e062fe24d974d99588b0ea7c831bce8b0a57/http%3A//schema.org" rel="nofollow">schema.org</a> types; unknown types still shown
  - Filter, expand/collapse all, JSON viewer, copy and download
  - Dark and light themes; accessible, keyboard-navigable UI

<strong>Privacy first</strong>
  Schema Preview is strictly read-only. It only reads markup already on the page, never modifies it, makes no network requests, and sends no data anywhere. No analytics, no tracking, no account.

<strong>Cross-browser</strong>
  Built on Manifest V3 for Firefox, Chrome, and Chromium browsers.

## Rankings

- #41,299 — Overall
- #54 — preview
- #156 — review

## Permissions and access

### Permissions

- `activeTab`
- `storage`
- `scripting`

### Host permissions

- `<all_urls>`

### Content script matches

- `<all_urls>`

## Safety

- **Risk impact:** Moderate risk impact
- **Risk likelihood:** High risk likelihood

### Analysis details

- Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site.
- This extension has low user count. Unpopular extensions may not be stable or safe.

> Some risk analysis details are omitted from this free response. [Upgrade to view the full analysis](https://chrome-stats.com/pricing).

## Similar extensions and apps

- [Schema Markup Validator](https://chrome-stats.com/d/schema-markup-validator) — 25 users
- [Rich Results & Schema Tester](https://chrome-stats.com/d/rich-results-schema-tester) — 18 users
- [JSON-LD Tester & Agent Inspector](https://chrome-stats.com/d/json-ld-tester-agent-inspector) — 9 users, 5.00 / 5
- [SEO Analyzer Tools](https://chrome-stats.com/d/seo-analyzer-tools) — 10 users
- [SEO Audit Pro](https://chrome-stats.com/d/seo-audit-pro) — 3 users
- [SiteLens-SEO](https://chrome-stats.com/d/sitelens-seo)
- [SEO Readability & Schema Checker](https://chrome-stats.com/d/seo-readability-schema-checker) — 1 users
- [Structure Checker - Structured](https://chrome-stats.com/d/structure-checker-structured) — 8 users, 2.00 / 5
- [Cyfrow SEO Meta Preview](https://chrome-stats.com/d/cyfrow-seo-meta-preview)
- [SEO Quick Check](https://chrome-stats.com/d/seo-quick-check) — 1 users
- [SERP Preview Tool](https://chrome-stats.com/d/serp-preview-tool) — 2 users
- [Playful Sparkle SEO Audit](https://chrome-stats.com/d/playful-sparkle-seo-audit) — 2 users

---

Source: [Chrome-Stats](https://chrome-stats.com/d/schema-preview)