Free SEO tool
Free Plagiarism Checker
Compare two texts side by side and see exactly which passages they share. Free, no sign-up, and your text never leaves your browser.
Web check is switched off for now
Checking text against the web needs a paid search service, and it isn't turned on yet. You can still , for example your draft and a page you think copied it. Compare mode is free, unlimited and runs in your browser.
Load text B from a web page
Results update as you type. Both texts stay in your browser; loading a page only sends its address to FindSEO.
Paste two texts to see how similar they are, with the shared passages highlighted.
Why copied content matters for SEO
Search engines want to show one good version of a piece of content, not ten copies of it. When the same text appears on several sites, Google picks the version it thinks is the original or most useful and filters the rest out of results. If a scraper or a careless supplier republishes your article, the copy can sometimes rank instead of you. Read more about duplicate content.
It works the other way too. Copy that a writer, agency or AI tool lifted from somewhere else adds nothing new, which is the opposite of the helpful, original content Google says it rewards. Checking before you publish is quicker than rewriting after a page fails to rank.
Two ways to check
Check against the web
Searching the web for your sentences needs a paid search service, so this mode is switched off for now. Compare mode below is free and unlimited.
Compare two texts
Paste your original and a suspected copy (up to 5,000 words each), or load the copy from a web page. You get a similarity score, how much of each text appears in the other, and the longest shared passages highlighted side by side. It runs in your browser.
Before you publish
- 1Check supplier and AI draftsRun copy from freelancers, agencies and AI tools before it goes live, especially product and service pages.
- 2Quote, then creditShort quotes are fine when they're marked as quotes and linked to the source.
- 3Use canonicals for syndicationIf you republish an article elsewhere, point a canonical tag back to the original.
- 4Rewrite boilerplateLocation pages and product descriptions copied from a manufacturer are the most common duplicates. Make each one genuinely different.
Learn how canonical tags work, or count repeated phrases with the Keyword Density Checker.
Need original content that ranks? Find a content SEO agency
Browse SEO agencies by location and service, or tell us what you need and we'll introduce you to up to three that suit your goals and budget. Free, no obligation.
More free SEO tools
- Schema Markup Generator and ValidatorBuild JSON-LD structured data, or check yours
- Meta Tag Generator and SERP PreviewPreview your search result and copy the meta tags
- Robots.txt Generator and ValidatorBuild a robots.txt file, check it and test URLs
- Keyword Density CheckerCount the words and phrases a page repeats most
All 16 free tools · Markup and content
Frequently asked questions
How is the similarity score in Compare mode worked out?
Both texts are broken into overlapping five-word phrases, ignoring case and punctuation. Similarity is the number of phrases they share divided by all the distinct phrases in both texts (Jaccard similarity). We also show how much of each text appears in the other, which is more useful when one text is much longer, and the longest passages they share.
Is my text saved or shared?
No. Compare mode runs entirely in your browser. For the web check, the text is sent to FindSEO and the sampled sentences are sent to our search provider for that one request; nothing is stored, cached or used for anything else. Reload the page and it's gone.
Does Google penalise duplicate content?
Not usually. Google's guidance is that duplicate content on its own isn't a penalty: it picks one version to show and filters the rest. The real risks are a copy outranking your original, wasted crawling on duplicate pages, and spam action against sites that scrape or spin other people's content at scale.
Someone copied my content. What should I do?
Keep evidence (screenshots and dates), make sure your original page is indexed and links internally to itself well, then contact the site owner and ask for removal or a link and credit. If that fails, you can file a copyright removal request with Google and the site's host. A canonical tag on syndicated copies keeps the credit with your page.
What counts as an acceptable similarity score?
There's no universal number. Quotes, product specifications, legal text and common phrases naturally overlap. Look at what matches rather than the percentage: one long shared passage matters more than many short common phrases.
Privacy: text you paste isn't stored. Compare mode never leaves your browser. Loading a page fetches only the address you enter, respects its robots.txt and doesn't get around bot checks. Results are an indication, not proof of plagiarism or of originality. See our privacy policy.