Text Similarity Checker
Compare two texts for overlapping phrases — not a web-search plagiarism checker
This compares the two texts you paste below against each other only — it has no connection to the internet or any academic database, so it cannot tell you whether your writing matches something published elsewhere. Use it to compare your draft against a specific source you're citing, or two of your own drafts — not as a substitute for your school's actual plagiarism-detection tool.
36.7%
of your text shares 6+ word phrases with the comparison text (47.8% of the comparison text shares them with yours; 6 shared phrases)
The same colour marks the same shared phrase in both texts. Hover a highlight to see its number.
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About Text Similarity Checker
Compares two texts you provide against each other and highlights overlapping phrases with a match percentage — a text comparison tool, not a web-search plagiarism checker, since it has no connection to the internet or any academic database.
Paste your text and the text you want to compare it against (or load a .txt, .docx or .pdf file into either box), and the overlapping phrases are highlighted in both texts, in matching colours, with a match percentage shown. You can change the shared phrase length from 4 to 8 words.
Use this to compare your draft against a specific source you're citing, or two of your own drafts — it's not a substitute for your school's actual plagiarism-detection tool, which checks against a much broader database.
Watch: Text Similarity Checker in Action
- Is this the same as my school's plagiarism-detection software?
- No — this is a text comparison tool for two texts you provide directly, not a web-search plagiarism checker, since it has no connection to the internet or any academic database. It's not a substitute for your school's actual plagiarism-detection tool.
- What is a text similarity checker?
- A text similarity checker compares two pieces of text and reports how much wording they share. This one takes the two texts you paste in, highlights the phrases that appear in both, and shows a match percentage. It is useful for comparing a draft with a source you are citing, or an old version with a new one.
- How is the match percentage calculated?
- The tool breaks both texts into overlapping runs of six words and looks for runs that appear in both. The percentage is the share of words in your first text that fall inside one of those shared runs, so copied phrases raise it and a few common words do not.
- Can I compare two documents written in another language?
- Yes. Letters and numbers in any script are recognised, and Chinese and Japanese text is compared character by character because those languages do not put spaces between words.
- Does a high percentage mean the text was copied?
- Not necessarily. Quotations, citations, standard phrases and shared terminology all count as matches. Read the highlighted passages to judge whether the overlap is quoted and cited or needs rewording.
How to use Text Similarity Checker
A text similarity checker compares two pieces of text and shows how much wording they share. Paste a draft and a source, or an earlier and a later version, and the shared phrases are highlighted along with a match percentage. Students, writers and editors use it to see how closely a draft follows a source they are citing, or how much a revision changed. It compares only the two texts you give it and does not search the web. Diff Checker shows the same pair line by line.
Paste your first text into one panel and the text you want to compare it against into the second. The tool analyzes both and highlights matching or closely overlapping phrases between them, along with an overall match percentage showing how much of the text overlaps. This is a direct, two-text comparison — it only ever compares exactly the two texts you provide against each other, nothing more.
When to use it
Useful for comparing your own draft against a specific source you're citing or referencing, to check how much of your wording overlaps with the original before you submit or publish something — catching accidental over-reliance on a source's exact phrasing before it becomes a problem. It's also useful for comparing two versions of your own writing (an early draft against a revision, for instance) to see concretely how much actually changed between them, beyond just a general sense that "it's different now."
When not to use it
This is explicitly not a substitute for an academic plagiarism-detection service — it has no connection to the internet or any academic database, and only ever compares the two specific texts you paste in against each other. If you need to check a paper against a broad database of published academic work, web content, or other students' submissions (the kind of check a university's plagiarism software performs), this tool genuinely can't do that — it can only tell you about overlap with a specific source you already have and paste in yourself.
Tips for best results
For checking overlap with a specific published source, copy the exact passage you're concerned about rather than the source's entire article or paper — comparing focused, relevant excerpts against your own draft gives a more meaningful match percentage than comparing your whole draft against an entire unrelated source document with mostly non-overlapping content.
Limitations
Because it only compares exactly two texts you provide, it can't catch similarity to any source you don't already have in hand to paste in — if the concern is unknown or undiscovered overlap with something you haven't specifically checked against, this tool won't surface that the way a database-backed plagiarism checker would.
Privacy
Both texts are compared entirely in your browser — neither text is uploaded to any server or external database, which also means neither text is added to any database other tools or services could later match against.
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