You have two copies of the same page, and Google has to pick one. If you don’t tell it which, Google decides for you.
The short version: keep one URL per piece of content, canonicalize the rest, and stop staging sites, parameters, or copy/pastes from competing with your primary page.
What is duplicate content? 🔍
It’s identical or near-identical content available on multiple URLs. Google rarely “penalizes” it; instead, it filters and shows one version. If the wrong version wins, you lose traffic.
Common sources: protocol/domain variants (www/non-www, http/https), URL parameters, printer views, syndicated copy without canonicals, or the same text reused across domains.
Fast fixes you can ship 🛠️
Do this
- 301 all variants into one canonical URL
- Add
rel="canonical"on duplicates - Noindex staging, test, and printer URLs
- For sort/filter parameters: canonical to the base and consider noindex
- Use consistent internal links to the canonical page
Avoid this
- Publishing the same text on multiple domains without a canonical back
- Letting staging/dev be indexable
- Creating printer/AMP/m-URLs without a canonical
- Using parameter URLs as internal links
Typical scenarios and the fix 🧭
Protocol/domain variants
301 everything to one (https + www or non-www). Put canonicals on all templates.
Parameters and filtering
Canonical to the parent category, noindex deep filter URLs, and create static landing pages for valuable filter combos.
Staging/test
Password protect and noindex. Never link from production.
Syndicated or guest-posted content
Ask for a canonical to the original. If not possible, rewrite and cite the source.
Product variants / printer views
Use one product page with variants. Noindex printer URLs or canonical back to the main page.
Internal duplication
Stick to one permalink per article. Don’t publish the same text in multiple categories without a canonical.
How to find duplicates ✅
- Google:
site:yourdomain.com intitle:"Title"to see if multiple URLs show the same page - Google Search Console: Coverage → Duplicate without user-selected canonical
- Crawl (e.g., Screaming Frog) to spot identical titles/meta and canonical breaks
- Index check: only one 200-URL should be canonical for each piece of content
Bottom line: pick one URL, point everything at it, and keep test and parameter clutter out of the index. That keeps your content visible.
Related terms 🔗
Duplicate content FAQ 🙋
Does duplicate content cause a Google penalty?
Usually no. Google typically filters duplicates and shows one version. The risk is that the wrong version ranks.
What is a canonical tag?
A canonical tag (rel='canonical') tells search engines which URL is the preferred version of a page.
What causes duplicate content on a website?
Common causes are URL parameters, www/non-www versions, http/https versions, printer views, staging sites, and reusing the same text across many pages.
How do I fix duplicate content?
Pick one URL, 301 redirect variants, add canonicals, and stop linking internally to duplicates. This is core SEO hygiene.
How do I find duplicates?
Use Google Search Console, site crawlers, and a simple site:yourdomain.com search to spot multiple URLs for the same content.