Duplicate Content Checker

Both pages' visible text is broken into overlapping 5-word phrases ("shingles"), and the percentage is the share of those phrases that appear in both pages — a standard technique for near-duplicate text detection. It measures textual overlap, not topic similarity, so two pages about the same subject written in completely different words will score low.

There's no official Google threshold, but in practice, overlap in the tens of percent from shared navigation, footers, and boilerplate is completely normal and harmless. It becomes worth addressing when the core content — the part that's supposed to make each page unique — is what's actually duplicated, which usually shows up as overlap well above that baseline.

Not usually as a manual penalty — Google's own guidance is that duplicate content is rarely treated as spam unless it's deliberately manipulative. The more common real cost is that Google picks one version to rank and effectively ignores the other, so near-duplicate pages compete with each other instead of each earning their own visibility.

Depends on intent: if one page should be the canonical version, add a canonical tag pointing to it (see the Canonical URL Analyzer). If both should exist and rank independently, differentiate their actual content. If one is genuinely redundant, consider merging or redirecting it.

It can compare any two URLs you give it, including a competitor's page — but it's not a web-wide plagiarism scanner. It only compares the two specific pages you enter, not your content against the entire internet.