10 Schema Markup Mistakes That Are Killing Your SEO (And How to Fix Them)
Discover the most common schema markup errors that prevent rich snippets and hurt your search rankings. Learn how to identify and fix these critical mistakes for better SEO performance.
Schema markup has the power to transform your search visibility, but only when implemented correctly. Unfortunately, many websites make critical errors that prevent rich snippets from appearing, confuse search engines, or even trigger manual penalties. After analyzing thousands of schema implementations, we've identified the ten most damaging mistakes and exactly how to fix them.
1. Mismatched Visible Content and Schema Data
The most serious and common mistake is adding schema markup that doesn't match what's actually visible on the page. Google explicitly requires that all structured data must represent content that users can see.
Common examples include: Adding FAQ schema for questions that don't appear on the page, marking up reviews that aren't displayed, showing different prices in schema than on the visible product page, or including hidden content just to game search results.
How to Fix: Audit every schema property against visible page content. If something appears in your schema, it must be visible to users on the page. Use Google Search Console to identify mismatched content warnings and correct them immediately. Remember: schema should describe existing content, not create new content.
2. Using Wrong Schema Types
Selecting incorrect schema types confuses search engines and prevents rich results from displaying. Each schema type has specific use cases and eligibility requirements.
Common mistakes include: Using Article schema for product pages, applying FAQ schema to forum or Q&A pages with user-generated content, marking blog posts as NewsArticle when they're not timely news, or using Review schema for testimonials that aren't actual product reviews.
How to Fix: Study schema.org documentation to understand each type's intended purpose. Use BlogPosting for blog posts, Article for general content, NewsArticle only for actual news, Product for e-commerce, and FAQ only for publisher-created Q&A content. When in doubt, use the more generic type rather than trying to fit content into a specialized category.
3. Missing Required Properties
Each schema type requires specific properties to be valid and eligible for rich results. Missing these essential fields invalidates your entire schema implementation.
For example: Product schema requires name, image, and offers. Article schema needs headline, image, datePublished, and dateModified. Review schema must include author, reviewRating, and reviewBody. Missing any required property means Google won't display rich results for that content.
How to Fix: Reference Google's official rich results documentation for each schema type you use. Create a checklist of required properties and verify each implementation includes all mandatory fields. Use Rich Results Test to identify missing properties before publishing.
4. Invalid JSON-LD Syntax Errors
JSON-LD is unforgiving of syntax errors. A single missing comma, bracket, or quote can invalidate your entire schema markup, rendering it useless.
Common syntax errors include: Missing commas between properties, unclosed brackets or braces, unescaped quotation marks in text strings, trailing commas after the last property, and incorrect nesting of objects and arrays.
How to Fix: Always validate your JSON-LD using a JSON validator before adding it to your site. Use code editors with JSON linting features that highlight syntax errors in real-time. For WordPress and other CMS platforms, use schema plugins that generate valid syntax automatically rather than coding manually.
5. Duplicate Schema Markup on Same Page
Having multiple instances of the same schema type on a single page creates confusion and can prevent rich results from appearing.
This often happens when: Multiple plugins or themes add schema automatically, manual schema is added without removing default theme schema, or when testing different implementations without removing old code.
How to Fix: View your page source and search for <script type="application/ld+json"> to find all schema instances. Remove duplicate schemas, keeping only the most complete and accurate version. If using WordPress, disable schema output in one plugin if multiple are active. Use browser DevTools to inspect all schema on your pages regularly.
6. Incorrect Date Formatting
Date properties must use ISO 8601 format. Using incorrect date formats causes validation errors and prevents rich results.
Wrong formats include: "01/15/2025", "January 15, 2025", "15-01-2025", or timestamps without timezone information. The correct format is "2025-01-15T10:30:00Z" or "2025-01-15T10:30:00-05:00" with timezone offset.
How to Fix: Always use ISO 8601 date format: YYYY-MM-DDTHH:MM:SSZ. Include timezone information. If using a CMS, ensure your schema generation handles date formatting correctly. Test dates in Rich Results Test to verify they're being parsed properly.
7. Low-Quality or Missing Images
Image properties are crucial for rich results, but many sites use images that don't meet Google's requirements.
Common image mistakes include: Images smaller than 1200px wide (Google's recommended minimum), using placeholder or generic images instead of actual content images, broken image URLs that return 404 errors, images that don't represent the page content, or using image formats that aren't supported.
How to Fix: Use high-resolution images (minimum 1200px wide) that accurately represent your content. Provide multiple images at different aspect ratios (16:9, 4:3, 1:1) for better display options. Verify all image URLs are accessible and return 200 status codes. Use modern formats like WebP or JPG/PNG.
8. Fake or Misleading Review Ratings
Adding fake reviews, manipulated ratings, or self-reviews violates Google's guidelines and can result in manual penalties or removal from search results.
Violations include: Creating fake customer reviews, writing reviews for your own products or services, cherry-picking only positive reviews, showing different ratings in schema than on the page, or adding aggregate ratings without any actual individual reviews.
How to Fix: Only include genuine customer reviews from verified purchasers. Display the same review data in both visible content and schema markup. If you don't have real reviews yet, don't add review schema. Use third-party review platforms to collect authentic feedback. Never manipulate or fabricate ratings.
9. Not Updating Schema When Content Changes
Static schema that doesn't update when page content changes becomes inaccurate over time, leading to mismatched data that can hurt SEO.
Common scenarios include: Product prices changing but schema still shows old prices, articles being updated but dateModified not changing, events passing but schema still showing future dates, or availability status changing without schema updates.
How to Fix: Implement dynamic schema that pulls data from your database or CMS, ensuring it always reflects current page content. Update dateModified whenever you make significant content changes. For products, connect schema to inventory systems for real-time availability. Regularly audit schema on important pages to verify accuracy.
10. Using Schema for Manipulation Instead of Description
Schema is meant to describe existing content, not to manipulate search results or add information that doesn't exist on the page.
Manipulative practices include: Adding keywords to schema that aren't on the page, creating FAQ schema with marketing copy disguised as questions, using schema to stuff additional promotional content, or adding properties with misleading information to gain unfair advantages.
How to Fix: Use schema ethically to accurately represent what's on your page. Follow Google's quality guidelines and schema.org specifications. Focus on providing accurate, helpful information that genuinely benefits users. Remember that search engines are increasingly sophisticated at detecting manipulation.
How to Identify Schema Errors on Your Site
Use these tools to find and fix schema issues:
- Google Search Console - Rich Results Report: Identifies which pages have schema errors and what types
- Rich Results Test: Tests individual URLs for schema validation and rich result eligibility
- Schema Markup Validator: Validates JSON-LD syntax and checks for missing required properties
- Chrome DevTools: View page source to see all schema markup and check for duplicates
- Screaming Frog SEO Spider: Crawl entire site to audit schema implementation at scale
Creating a Schema Quality Checklist
Before implementing schema, verify:
- All schema data matches visible page content exactly
- Correct schema type selected for the content purpose
- All required properties included with valid values
- Valid JSON-LD syntax with no errors
- Only one instance of each schema type per page
- Dates in proper ISO 8601 format
- High-quality images meeting size requirements
- Genuine reviews and ratings if included
- Schema updates dynamically with content changes
- Implementation follows Google's guidelines ethically
Conclusion
Schema markup mistakes can completely negate the SEO benefits of structured data or, worse, result in penalties that hurt your overall search performance. By avoiding these ten common errors and following best practices, you'll ensure your schema implementation delivers the rich results, improved visibility, and increased traffic you're looking for.
Audit your existing schema regularly, stay updated on Google's guidelines, and always prioritize accuracy and user value over short-term manipulation tactics. Proper schema implementation is a long-term SEO investment that pays dividends when done correctly.