Looking for a Copyleaks alternative? Split the AI question from plagiarism

This site is a free AI checker and AI humanizer, and it keeps the AI question and the plagiarism question in separate tools. Plagiarism checking asks whether your text already exists somewhere else. AI detection asks whether your writing reads as machine-generated. The checker takes at least 65 words and returns a 0 to 100 AI score with one of three labels: Reads as AI-generated, Borderline, or Reads as human-written, and one run costs one credit whatever the length. The humanizer rewrites every sentence in one click, up to 12,000 characters per run, roughly 2,000 words, at one credit per 50 words. The free tier is 10 credits a day per network, with no account, no login, no card and no email address. A plagiarism and originality check, a proofreader, a word counter, a readability checker, an AI vocabulary checker and a signed drafting record cost no credits and have no daily cap. This site is not affiliated with Copyleaks and is not endorsed by it.

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Two questions, two kinds of evidence

A similarity check answers a question about the world outside your document. It matches your words against text that already exists and attaches a source to every overlap it reports. You can open that source and see whether the match is a lifted paragraph, a correct quotation, or a phrase thousands of pages contain.

An AI reading answers a question about the document itself. Nothing outside your text is consulted, so there is no external record to point at. What gets measured is how the writing behaves: how much sentence length varies, how predictable the next word is, how many hedges stack inside one clause. It is a judgment about style, so it can land on prose no machine ever touched. That is why the two numbers deserve different treatment: a similarity percentage can be argued about on the facts, and an AI percentage on its own is a reading with nothing attached.

  • The plagiarism question: does this passage exist elsewhere? Settled by producing the source.
  • The AI question: does this read as machine-written? Settled by properties of the text, with no outside document involved.
  • The failure modes differ too. A perfect citation still pushes a similarity score up, and careful, taught, textbook-clean prose still pushes an AI score up.

What the checker on this page does

Paste at least 65 words and run the check. You get a 0 to 100 AI score and one of three plain labels: Reads as AI-generated, Borderline, or Reads as human-written. A run costs one credit whatever the length, so scoring a long section costs what scoring one paragraph costs. On a long document, work a section at a time: one score for a whole dissertation is an average, and an average hides the chapter that reads as machine-written.

The score is the starting point rather than the finish. The registry of named AI writing tells runs in your own browser tab, costs no credits and has no daily cap. It highlights the constructions a classifier keys on: the stock opener that announces the era, the not just X but Y pivot used as rhythm instead of argument, the line reporting that an event "underscores the importance" of something. Editing a named sentence is work you can do. Arguing with a number is not.

What the originality check reports

The plagiarism and originality check reads your draft for the defects that are still yours to fix and names each one in place: repeated passages, quotations with nobody credited, citations that do not line up with your reference list, and figures with no source. Those are the sentences a marker circles, and a percentage never mentions them.

These document checks run in your own tab, cost no credits and have no daily cap, alongside the proofreader, word counter, readability checker, AI vocabulary checker and signed drafting record at free AI writing tools. If your institution grades through its own similarity platform, that report is the one that decides the case, so clean the draft before it gets there.

  • Repeated passages: any run of eight words or longer that appears twice, which is how a pasted paragraph or a restated thesis surfaces.
  • Quotations with no attribution: inline quotes of six words or more, block quotes of four or more, with nothing within twenty words either side naming whose words they are.
  • Citation problems: APA, MLA and numeric citations cross-checked against the reference list both ways, so malformed entries, citations with no reference, and references never cited all show up.
  • Unsourced claims: percentages, large numbers, money, ratios and appeals like studies show, when no citation appears within fifteen words in the same paragraph.

The step after the score: the rewrite

A detection report tells you where you stand. It does not change the draft. The humanizer here is the part that does, and it draws on the same free credits as the checker. One click rewrites every sentence in the passage. A single run takes up to 12,000 characters, roughly 2,000 words, with a minimum of 25 words, at one credit per 50 words.

The loop worth running is check, rewrite, check again. The second check is the point, because it shows where the score actually landed instead of asking you to trust that something improved. Ten free credits a day covers one check, 400 words of rewriting and a second check, which comes to exactly ten. On a longer piece, score the section you are worried about, fix the tells you can already see by hand, and spend the credits on the paragraphs that resist editing.

Which tool your situation actually calls for

These are not interchangeable products, and pretending otherwise wastes your afternoon. Here is the sorting, including the cases where something else is the right buy.

  • Your institution runs submissions through a licensed platform. That report is the evidence in your case. Use this site to get an AI reading and clean the draft first.
  • You need an API, an LMS integration, or scanning across an organisation's accounts. That is enterprise procurement. This site is a free browser tool for one draft at a time.
  • You have one deadline and want a private read before you hand the draft in. That is what 10 credits a day covers, with nothing to sign up for and nothing to cancel.
  • You generated a permitted first draft and it reads flat. Check it, look at which tells fired, then rewrite the passages carrying the reading.
  • You wrote every word and something flagged you anyway. Check it to find which sentences caused it, then read why detectors flag human writing and you wrote it and were accused.

If you were flagged and you wrote it yourself

This is the case where treating an AI score like a similarity match does real damage. The clearest published measure of how wrong these systems can be comes from Liang and colleagues at Stanford HAI in 2023: across seven detectors, 61% of TOEFL essays by non-native English speakers were falsely flagged as AI-generated. Those essays were written by people. A similarity hit can be checked against its source. An AI flag cannot, so read it as one opinion rather than a verdict.

Two pages here are written for that side of it rather than for selling you a rewrite. For second-language writers covers the taught constructions that carry the most risk, including the essay scaffolding many exam courses teach. For teachers covers what a detector score is worth as evidence about a student. If you want to show your process next time, the signed drafting record signs the draft as it was written with an ECDSA P-256 key, and verify a report checks a report against the key it carries, so a third party can confirm it without contacting us.

Test it on your own paragraph, and one note on policy

We publish no comparison figures against Copyleaks or any other product, and we make no claim about what any third-party system will report about your text. Those classifiers are private and their owners retrain them on their own schedule.

What you can do in a few minutes is run 200 words of your own writing, not a sample from a marketing page. Note the score, note which tells fired, rewrite, then check again and read the result aloud. You are looking for two things: whether the number moved, and whether it still sounds like you. One line on policy, then back to the writing. Rewriting a draft you were permitted to generate is ordinary editing. Where AI is not permitted in submitted work, that rule covers the draft however it is edited.

Questions people actually ask

Looking for a Copyleaks alternative? Split the AI question from plagiarism: common questions

Is this a free plagiarism checker?

The originality tool is free and unmetered, and it is best to be precise about what it returns. It reads your document and names four kinds of defect: repeated passages, quotations with no attribution nearby, citation and reference-list problems, and figures with no source. Those are real defects that a percentage will never point at. If your submission is graded through your institution's own similarity platform, that report is the one that counts, and this is the check that cleans the draft before it gets there.

Do I need an account or a card?

No. There is no account, no login, no card and no email address, and nothing to verify. The free tier is 10 credits a day, counted per network, and it refreshes daily. Because nothing is registered, there is nothing to cancel.

Will this tell me what Copyleaks will say about my text?

No, and any tool promising you a specific result on a third-party system is promising something it does not control. Those classifiers are private, they are retrained without notice, and they publish no thresholds. The score here comes from this site's own checker on its own scale, so read it as a reading of your draft rather than a prediction about someone else's software.

What does one credit buy?

A check costs one credit whatever the length, from a 65-word paragraph to a full chapter. A rewrite costs one credit per 50 words. So a day of 10 credits covers, for example, one check, 400 words of rewriting, and a second check to see where the score landed. The in-browser tools are not metered at all: the tells registry, proofreader, word counter, readability checker, AI vocabulary checker, originality check and signed drafting record have no credit cost and no daily cap.

How much text can I run at once?

A check needs at least 65 words and costs a single credit at any length, so there is no reason to sample when you can score the whole section. A rewrite takes up to 12,000 characters in one run, which is roughly 2,000 words, with a 25-word minimum. For anything longer, check first, then rewrite section by section, starting with whichever section scored worst.

Is my writing sent to a third-party detector?

No. The check runs on this site's own engine, and your draft is not passed to any other company's detection service. The browser tools, including the originality checks, the tells registry and the signed drafting record, compute their results in your own tab.

My school uses a detection platform. Can I still use this?

That depends on your course policy, and the policy is the only thing that decides it. Rewriting a draft you were permitted to generate is ordinary editing. Where AI is not permitted in submitted work, that rule covers the draft however it is edited. If you are checking your own writing because you have been flagged before, that is a different situation, and the pages on false positives and on being accused are written for it.

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