What file types can I upload?

The Upload File button reads plain-text files (.txt and .md). Working in Word or Google Docs? Copy your text and paste it in. Nothing is lost, and the check runs on exactly what you pasted.

How accurate is this plagiarism checker?

Every match it reports is real. The overlapping passage sits next to the live page it came from, so you can verify each one yourself. No checker sees every source, though: paywalled archives and unindexed pages are invisible to any web-matching tool. So a clean result is strong evidence of originality, not a certificate.

How is the similarity score calculated?

It's the share of your document that overlaps with published sources: matched words divided by total words. The report breaks it down by passage and by website, so a 20% score is a list of findings you can open and resolve one by one.

Plagiarism Checker

Detect plagiarism, fix duplicate content, and verify your document in minutes.

Live web search

Every match shows its source

Fix it right in the editor

Your documents are never indexed, resold, or used to train detection models.

The check

What this check looks for

It matches your text against published web sources and shows each match with its source and the overlapping passage. No bare scores: every finding says what was found and why it matters.

The honest part: no tool sees every source. A clean result is strong evidence your text is original, not a guarantee. You're checking your own work, privately, before it counts.

Similarity

89%

Live estimate after your edits. Re-run to verify.

Similarity89%

Issues remaining3/14

Matched593

Sources13

Findings14

Exact match13% of document

“The mitochondria is often described as the powerhouse of the cell, converting nutrients into usable energy through cellular respiration…”

encyclopaedia.orgmatches 92% of that page

Side by side

See the source, not just a score

Select any match and its source page opens beside your document, with the overlapping passage highlighted in both. No copied URLs, no guessing.

Cell_Biology_Assignment.docxYour document

How Cells Produce Energy

Energy production in eukaryotic cells is remarkably efficient, and most of it takes place inside a single organelle.

The mitochondria is often described as the powerhouse of the cell, converting nutrients into usable energy through cellular respiration. This process sustains nearly every activity the cell performs, from growth to repair.

When energy demand rises, cells can increase the number of mitochondria they contain. Muscle tissue in trained athletes shows this adaptation clearly.

encyclopaedia.org/biology/cell-energy

Open

EncyclopaediaBiologyChemistryPhysics

Cell biology: energy and metabolismReviewed article · Updated March 2026

Every living cell must generate energy to survive. The mitochondria is often described as the powerhouse of the cell, converting nutrients into usable energy through cellular respiration. In plants, chloroplasts capture light energy alongside this process.

The efficiency of this conversion varies with oxygen availability, which is why aerobic respiration yields far more energy than fermentation.

The overlapping passage is highlighted in your document and on the page it matched.

How it works

Hand it in with confidence

Close paraphrasing happens to everyone, and it's easy to miss in your own draft. See every match privately, then credit the source or rewrite the line.

Find

See each matched passage with its source, explained.

Fix

Cite it, rewrite it or clear it. Your call, right in the document.

Re-check

Confirm it's resolved before you submit.

Included

What you get with every check

Suggested rewrites

Accept a rewrite that keeps your meaning and clears the match.

Citation help

Quoting on purpose? Turn the match into a proper citation.

Source breakdown

See how much of your document each website accounts for.

26 languages

English and 25 more. Sources are searched in the language you write in.

More checks

Make your document even stronger

Check for AI detection

See how likely your text reads as AI-written, with the uncertainty shown, so your own voice comes through.

Check my document

Check your readability

Rewrote a passage? Make sure it still reads smoothly.

Check my document

Frequently asked questions

Try it free on your own document.

Upload once. Fix what matters.