How do I check my paper before I submit it?

Work in three passes. Run the grammar check in the first box. Paste the same text in the second box for the plagiarism check and tick the AI detector. Then add any missing citations and check the grammar once more.

Can I check a full research paper?

Yes, in sections. Without an account the grammar check takes up to 10,000 characters and the plagiarism and AI checks take up to 1,000 words. A free account gives you 3,000 words every month, and paid plans add longer documents.

Will my quotes and references show up as matches?

They can. A plagiarism check finds text that matches other sources. It does not judge whether you cited it. A quote in quotation marks with a citation is not plagiarism, even when the report shows a match. Open the linked source and check each one yourself.

Does it check that my citations are in the right format?

No. It shows which passages match other sources, so you can see what still needs a citation. To build the citation itself in APA, MLA or Chicago style, use the citation generator.

Can it tell if a paper was written by AI?

It gives a likelihood, not proof. Each sentence gets a likelihood and the paper gets an overall score. Any detector can flag writing a person wrote, so a score should never be the only basis for an academic integrity decision. Keep your drafts and notes.

Will it rewrite my paper for me?

No. Plagiarism Checker Plus does not rewrite, “humanize” or lower a score. It shows grammar issues, matching sources and AI-like sentences, and you decide what to change.

Is my paper kept private?

Your paper is used to run your check and is never used to train AI models.

Free paper checker

Paste a section of your research paper, term paper or report to check grammar, spelling and punctuation. Then check it for plagiarism and AI writing below. No sign-up.

Language

Suggestions

Suggestions appear here

Paste your text and click “Check grammar”. Each issue is underlined by category: grammar, spelling, punctuation or style.

Grammar
Spelling
Punctuation
Style

0 / 10,000 characters

Free to use. Your text is checked and not stored.

No sign-up required
Free up to 10,000 characters
14 languages, 6 English variants

Grammar check free, no sign-up
Plagiarism and AI check below
Never used to train AI

Step 2

Check your paper for plagiarism and AI

Paste the same section here. Your first check is free without an account, up to 1,000 words. Plagiarism needs at least 30 words and AI detection at least 50.

Plagiarism AI detector

0 / 1,000 words·0 chars

Scan options

Also run AI detectorOne scan, one report — plagiarism + AI together

What you get

Billions of web pages, journals & sources
Sentence-by-sentence similarity report
Auto-detects your language
No signup needed for your first scan

What it checks

Writing, sources and AI in one place

A paper built on sources has more ways to go wrong than a typo. This page checks the writing and shows where your text matches something already published.

Grammar, spelling and punctuation

Run the grammar check on each section of the paper. It is free with no sign-up and does not use any words from your plan.

Matches with your sources

The plagiarism report links each matching source. Use it to find a quote that lost its quotation marks or a paraphrase that has no citation yet.

AI writing

The paper gets an overall AI score and each sentence gets a likelihood. That is a probability, not proof, and any detector can flag writing a person wrote.

A match is not the same as plagiarism. A quote with quotation marks and a citation can still show as a match. See how to interpret a plagiarism report.

How it works

How to check your paper in 4 steps

Clean up the writing
Paste a section of your paper in the checker at the top and run the grammar check. Go through the suggestions one by one.
Check it against other sources
Paste the same section in the second box and run the plagiarism check. Open each linked source and compare it with your text.
Add the AI check
Tick the AI detector to get both results in one report. Reread the flagged sentences in context.
Fix the citations
Quote or cite every match that needs it, add the source to your reference list, then repeat for the next section.

What is free

Free limits for a long paper

Most papers are longer than one free check. Here is what you can do without an account.

Free limits for each paper check without an account
Check	Free without an account	Good to know
Grammar, spelling and punctuation	Up to 10,000 characters per check. No limit on the number of checks.	Does not use any words from your plan.
Plagiarism	First check free, up to 1,000 words.	Needs at least 30 words.
AI detection	First check free, up to 1,000 words.	Needs at least 50 words.

A free account gives you 3,000 words every month. Paid plans add longer documents. See pricing.

Know the limits

What a paper checker can’t do

It finds errors, matching sources and AI-like sentences. The research and the argument are still yours.

It does not grade the paper

You get issues, matches and scores to act on. Your instructor’s rubric and your argument decide the grade.

It does not rewrite or “humanize”

Nothing in your paper changes unless you change it. The checks do not rewrite text or lower a score for you.

It does not settle authorship

An AI score is a probability. It should never be the only basis for an academic integrity decision.

Build your reference list with the citation generator in APA, MLA or Chicago style. For a short essay, use the essay checker. Then read how to avoid plagiarism.

More free writing tools

FAQ

Paper checker questions

Yes. The grammar check is free with no sign-up for up to 10,000 characters at a time, and it does not use plan words. Your first plagiarism check and first AI check are free without an account, up to 1,000 words. A free account gives you 3,000 words every month.

Check your paper before you submit it

Grammar is free with no sign-up. Your first plagiarism and AI check is free up to 1,000 words.

Check my paper Check for plagiarism