Duplicate content is when identical or near-identical content appears on multiple URLs — either within your own site or across different domains. It doesn’t usually trigger a “penalty,” but it does force search engines to choose which version to rank, which can dilute ranking signals and waste crawl budget.
Common internal causes: URL parameters (tracking codes, filters, session IDs) creating multiple versions of the same page, www vs. non-www or HTTP vs. HTTPS both being accessible, printer-friendly page versions, and paginated content that isn’t handled correctly.
Common external causes: Content syndicated to partner sites without proper attribution, or scrapers republishing your content elsewhere.
How to diagnose it: Use Search Console’s Coverage report to check for “Duplicate, Google chose different canonical than user” — this flags cases where Google picked a different page than you intended. Tools like Screaming Frog can also crawl your site and flag pages with identical or near-identical title tags and content.
How to fix internal duplication: 1. Set canonical tags pointing to the preferred version of each page. 2. Use 301 redirects to consolidate genuinely duplicate URLs into one. 3. Standardize on one version — www or non-www, trailing slash or not — and redirect all variants to it. 4. Use noindex for low-value duplicate pages like print versions.
How to handle external duplication: For syndicated content, ask partners to include a canonical tag pointing back to your original, or a link back to the source article.
