Top 5: marking up content not visible on the page, using fake reviews, schema mismatch with page content, multiple conflicting schemas on one page, and schema that doesn't validate. All five trigger algorithmic downweighting and can lead to manual actions.
Twelve years of auditing client sites surfaces the same patterns repeatedly. Here are the most-common, most-damaging schema mistakes:
**1. Marking up content that isn't visible to users.**
Google's policy: schema must reflect content visible to users when they visit the page. Common violations:
- FAQ schema with 10 questions; only 4 actually visible on page - Review schema for reviews displayed on a different page - Author schema with credentials not actually mentioned on the bio page - Product schema with prices not shown anywhere on the product page
**Fix:** audit one page type at a time. For each schema property, ask "where on this page does the user see this?" If the answer is "they don't," remove the property.
**2. Fake or aggregated reviews.**
Marking up review scores aggregated from third-party platforms (Yelp, Google) as if they were first-party reviews. Or fabricating reviews entirely.
Google's "Spammy Structured Markup" manual action specifically targets this. Penalty: site-wide rich snippet eligibility revoked.
**Fix:** only mark up reviews you've collected directly. Aggregate scores from Google Business Profile separately (don't put them in your site schema).
**3. Schema that contradicts visible content.**
A page titled "Drain Cleaning Services in Ottawa" with Service schema typed as "Roofing" and areaServed listing Toronto. Or product schema with price $100 when the visible price is $1,000.
These mismatches often happen from copy-paste errors when expanding to new pages. Google's parsers detect contradictions and ignore the schema entirely (or worse, trigger manual review).
**Fix:** validate every page after deploying. Use Sitebulb or Screaming Frog to crawl all schema and flag contradictions with visible content.
**4. Multiple conflicting schemas on one page.**
A service page with three Service schemas, two LocalBusiness schemas, four Article schemas, and a Product schema. Often happens when a CMS auto-injects schema and a separate plugin also injects schema, and neither is configured to defer.
**Fix:** use one canonical schema strategy per page type. Disable auto-injection from competing plugins. Validate with Rich Results Test after every theme or plugin update.
**5. Schema that doesn't validate.**
Missing required properties, malformed JSON, incorrect property types (string where number expected, etc.). Google ignores invalid schema entirely — you get no benefit but your page weight increases.
**Fix:** Rich Results Test (search.google.com/test/rich-results) on every page template. Schema.org Validator (validator.schema.org) for spec-level validation.
**6. Stale schema after content updates.**
Product prices change but schema doesn't update. Article `dateModified` never gets bumped. AggregateRating reviewCount stuck at "47" for 2 years even though new reviews keep coming in.
**Fix:** schema generation should be tied to dynamic data sources, not hand-coded values. If you update a price in your CMS, the schema should auto-update.
**7. Misusing Microdata + JSON-LD on the same page with different values.**
Legacy theme injects Microdata; SEO plugin injects JSON-LD; the two report different prices, ratings, or descriptions. Google's parsers can't reconcile and may pick the wrong one or ignore both.
**Fix:** standardize on JSON-LD. Strip out legacy Microdata.
**8. Generic Schema.org Thing or generic Page types.**
Falling back to `@type: "Thing"` or `@type: "WebPage"` when a more specific type exists. Generic types convey no useful signal.
**Fix:** look up the most-specific type that fits your content. The Schema.org type hierarchy is at schema.org/docs/full.html.
**9. SameAs to profiles you don't actually own.**
Linking to "the famous expert" social profiles when those profiles aren't yours. Google's entity resolution is sophisticated enough to detect mismatches.
**Fix:** sameAs only the profiles you control and that link back to your domain.
**10. Forgetting to update schema after a redesign or migration.**
A site redesign adds beautiful new visible content but inherits 5-year-old schema describing the old content. Common after agency hand-offs.
**Fix:** make schema audit part of every redesign QA checklist. Specifically validate that all schema URLs match new URL structure, all visible content matches schema content, and no orphaned schema references the old structure.
- **Should I use JSON-LD, Microdata, or RDFa for schema markup?** — JSON-LD, period. Google has explicitly stated JSON-LD is preferred since 2017. Microdata and RDFa still parse correctly but add no benefit and complicate maintenance. Strip out any old Microdata when you migrate. - **Is FAQ schema still worth implementing in 2026?** — Yes, but with reduced expectations. Google removed FAQ rich snippets from most non-authoritative sites in August 2023 and continued tightening through 2024–2025. FAQ schema still helps with semantic understanding and AI Overview citations, even when rich snippets don't display. - **Can I use Product schema for service businesses?** — Yes — Service schema (a Product subtype) is the right choice for service businesses. Don't use the generic Product schema for services; use Service, with proper offers, areaServed, and provider properties. - **How do I add AggregateRating schema without violating Google's guidelines?** — Only mark up reviews that are genuinely visible on the page, came from real customers, and are first-party (collected by you, not aggregated from elsewhere). Google's 2019 review snippet update made fake or third-party-aggregated review markup ineligible for rich results.