Duplicate content is one of the most persistent problems in SEO. When two pages share substantially the same text – whether through content scraping, accidental syndication, or thin pages generated by CMS templates - search engines may struggle to decide which version to rank, or may reduce visibility for both. Our Duplicate Content Checker lets you compare any two pages or text blocks in seconds, giving you a clear similarity score, shared phrase list, and a word-level highlighted comparison.
Duplicate Content Checker
Compare two URLs or paste two blocks of text to check for duplicate or near-duplicate content. Get a similarity score, word overlap analysis, and a highlighted comparison view.
Both pages must be publicly accessible. The tool fetches and extracts visible text from each page server-side.
Similarity Thresholds
- 90–100% Very high — near-identical or duplicate content
- 70–89% High — substantial overlap, likely a duplicate issue
- 50–69% Moderate — significant shared content worth reviewing
- 30–49% Low — some overlap, probably not a concern
- 0–29% Minimal — content is largely unique
Enter two URLs or paste two blocks of text and click Check for Duplicates.
Why Choose Our Duplicate Content Checker?
- Two input modes: enter two live URLs to fetch and compare real pages, or paste two blocks of text directly for instant client-side analysis.
- Similarity score from 0 to 100%, calculated using Jaccard similarity on unique word sets – a well-established method for detecting content overlap.
- Clear verdict with a colour-coded label (Near-Identical, High Similarity, Moderate, Low, Minimal) so you know at a glance how serious the overlap is.
- Content statistics panel shows word count for each text, shared unique words, and sentence counts for both documents.
- Top shared phrases list surfaces the longest matching word sequences (up to 5-grams) found in both texts, helping you identify which specific passages are duplicated.
- Side-by-side word comparison highlights every shared word in both texts simultaneously, making it easy to spot where the overlap is concentrated.
- Completely free. No account or login required.
Our Duplicate Content Checker is perfect for:
- SEO professionals auditing a site for thin or templated pages that share large amounts of boilerplate content.
- Content managers who want to check whether a new article is too similar to existing published content before going live.
- Website owners who suspect their content has been scraped and republished without permission.
- Agencies comparing client pages against competitor content to understand overlap in messaging.
- Publishers syndicating content who need to verify that each syndicated version is differentiated enough to avoid duplicate content penalties.
How to Use Our Duplicate Content Checker:
- Choose your input mode: “Compare URLs” to fetch and compare two live pages, or “Compare Text” to paste content directly.
- Enter the two URLs or paste the two text blocks you want to compare.
- Click “Check for Duplicates” – the tool will analyse both texts and produce results immediately.
- Review the similarity score and verdict at the top of the results panel.
- Check the Content Statistics for word counts and the number of shared unique words.
- Scan the Top Shared Phrases to see which specific passages appear in both texts.
- Use the Word-Level Comparison to see exactly where the shared words are concentrated in each text.
If the similarity score is above 70%, you should take action – either consolidate the pages, use canonical tags to indicate the preferred version, or rewrite one of the pages to meaningfully differentiate the content. A score below 30% is generally nothing to worry about.
Frequently Asked Questions
What similarity score should I be concerned about?
As a general rule, a similarity score above 70% indicates a potential duplicate content issue worth addressing. Scores above 90% suggest the content is near-identical and could lead to ranking problems for both pages. A score between 30 and 70% may or may not be a problem depending on the type of content - some overlap is natural for topic-adjacent pages. Scores below 30% are rarely a concern.
Does duplicate content lead to a Google penalty?
Google does not apply a manual penalty for most cases of duplicate content. Instead, it tries to choose the best version to index and may reduce the visibility of the others. In extreme cases – particularly with scraped content – it may filter duplicate versions from search results entirely. The bigger risk is diluted link equity and split ranking signals across pages that should be consolidated. Using canonical tags or 301 redirects is usually the right fix.
How is the similarity score calculated?
The tool uses Jaccard similarity, which compares the unique word sets of both texts. It counts how many unique words appear in both texts (intersection) and divides by the total number of unique words across both texts combined (union). The result is expressed as a percentage. This method is effective at detecting word-level overlap without being thrown off by word order or minor phrasing differences.
Can I use this tool to check if someone has copied my content?
Yes. Paste your original content into Text 1 and paste the suspected copy into Text 2, or enter the two URLs directly. A high similarity score confirms meaningful overlap. If your content has been copied without permission, you can file a DMCA takedown request with the hosting provider or Google Search Console to have the infringing page removed from search results.
Why does URL mode sometimes return different results to text mode?
When comparing URLs, the tool fetches each page server-side and strips away navigation, scripts, and other non-content elements before analysing the text. This means the word count and similarity may differ from a manual copy-and-paste, which often includes hidden or repeated text from menus, footers, and sidebars. For the most accurate comparison of body content specifically, using text paste mode with the article content only will give you the most precise result.
