What Is Duplicate Content and How Does It Hurt SEO?
Duplicate content is substantially similar content reachable on more than one URL. It is rarely a penalty, but it splits ranking signals: links, engagement and crawl budget get divided across the copies, so no single URL reaches its potential. 41% of pages we audited also lack canonical tags, which is how most accidental duplication happens.
The common causes
- http and https, or www and non-www versions both live.
- Print pages, tag archives and sort parameters creating copies.
- Copying manufacturer or affiliate descriptions verbatim.
- Site templates without canonical tags.
How to check yours free
Run the suspected pages through the Duplicate Content Checker, then confirm each page has a self-referencing canonical with the On-Page SEO Checker.
Frequently Asked Questions
Will Google penalize me for duplicate content?
No penalty for accidental duplication. It just picks one URL, possibly the wrong one.
How much overlap counts?
There is no fixed percentage. Paraphrased and expanded versions are treated as unique.
Related reading
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