Copyleaks AI Detector: Review & Free Check
Paste any text below for a free AI score, no account needed. This is Humanit's checker, not Copyleaks itself. Under it: how Copyleaks decides text is AI, where your school is probably running it, and how much weight its score deserves.
Copyleaks is an AI and plagiarism detector sold mainly to schools and businesses. Its AI Logic feature shows why text was flagged by pointing to phrases that appear far more often in AI writing than in human writing, and it plugs into Canvas, Moodle, Blackboard, D2L and other LMSs, so many students meet it without ever visiting copyleaks.com.
Works with every major AI model
How it works
- 1Paste your text. Drop in the writing you want to check against Copyleaks-style detection.
- 2Run the free detector. Humanit returns a 0–100 AI-likelihood score, a verdict, and the signals behind it.
- 3See what reads as AI. The subscores show which patterns — predictable phrasing, uniform rhythm, stock vocabulary — are pulling the score up.
- 4Fix it if needed. If it reads as AI, send it to the humanizer to rewrite those signals, then re-check.
Where you actually run into Copyleaks
Most people who search for the Copyleaks AI detector have not chosen it. Copyleaks sells an LMS integration for Canvas, D2L, Moodle, Blackboard, Schoology, Edsby and Sakai, so when a school switches it on, submissions get scanned inside the course page itself. That is also why "does Canvas detect AI" has such a confusing answer: the learning platform does nothing on its own, but a plug-in like Copyleaks or Turnitin can — the full picture is in does Canvas detect AI?. Beyond schools, Copyleaks ships a Chrome and Edge extension, a Google Docs add-on, and an API that businesses white-label into their own products.
How Copyleaks decides text is AI: AI Logic
Copyleaks scores text with a model trained on human and machine writing, then explains the result with a feature it calls AI Logic. AI Logic has two parts. AI Phrases highlights wording in your document that shows up far more often in AI-generated text than in human text, with the statistical frequency behind it. AI Source Match flags passages that already appear in content published elsewhere, which is where the AI check and the plagiarism check meet. That is more explanation than most detectors give, and it is the right instinct: a flag you can inspect is one you can argue with. It is still a statistical judgement about phrasing, not a record of who wrote the words.
The Grammarly problem, in Copyleaks' own words
Copyleaks publishes a warning worth knowing before you panic about a score: platforms such as Grammarly use ChatGPT and other generative models for key features, so writing polished with them can be flagged as potential AI content. In plain terms, a human draft that went through heavy AI-assisted editing can look machine-written to Copyleaks. If you use Grammarly, the Grammarly AI detector page explains how that tool's own detector and its Authorship log treat the same situation.
How accurate is Copyleaks?
Copyleaks advertises near-perfect accuracy backed by third-party studies and says it can find AI text even when it is blended with human writing. Treat that as a vendor claim, measured on the test sets it chose. The independent picture for detectors as a class is less flattering: a 2023 peer-reviewed study in Patterns found more than 61% of genuine TOEFL essays by non-native English speakers misclassified as AI across the detectors it tested, and edited AI text is consistently harder for every tool to catch. The practical reading is the same for Copyleaks as for any detector: a strong result on long, unedited AI text is meaningful; a middling score on your own polished writing is not proof of anything.
What Copyleaks costs
Copyleaks is free to start, and its paid plans are priced in credits that cover AI and plagiarism scans together. On its pricing page the Personal plan is billed at $167.88 a year and includes 1,200 unified credits, which Copyleaks says covers up to 300,000 words, along with AI Logic, multi-file uploads and the browser extension; the larger plan adds whole-website scanning and ten times the credits. Institutions buy it separately through the LMS integration, which is how most students end up being scanned by it.
Checking your own writing before Copyleaks does
If your course runs Copyleaks, check your draft first somewhere that shows its reasoning. Humanit's detector above is free with no account for up to 300 words per check and returns a 0–100 score with the sub-signals behind it — perplexity, burstiness, AI vocabulary, structure — plus the exact phrases pulling the score up. It is a different model from Copyleaks, so the numbers will not match; what carries over is which passages read as machine-written. Fix those by varying sentence length, cutting stock transitions and adding specific detail, and keep your drafts and version history, which settle more disputes than any score.
Who it's for
| Feature | Copyleaks | Humanit detector |
|---|---|---|
| Free check without an account | Free to start; paid plans in credits | Yes, up to 300 words per check |
| Explains why text was flagged | AI Logic: AI Phrases + AI Source Match | Sub-signals plus the exact phrases that read as AI |
| Plagiarism in the same report | Yes | No |
| Runs inside your school LMS | Canvas, D2L, Moodle, Blackboard, Schoology, Edsby, Sakai | No |
| Languages | 30+ | English-tuned |
| Rewrite flagged text in place | No | Yes, humanizer on the same page |
Frequently asked questions
Is this the official Copyleaks AI detector?
No. This is Humanit's free detector for the same job, so you can check a draft before Copyleaks or an instructor does. We have no access to your Copyleaks account or your school's Copyleaks reports.
Is Copyleaks AI detector accurate?
Copyleaks advertises near-perfect accuracy backed by third-party studies. Independent research on detectors as a class finds real false-positive rates, especially on non-native English and heavily edited writing, and weaker results on edited AI text. Treat a Copyleaks score as a reason to look closer, not as proof.
Is Copyleaks AI detector free?
You can start for free, and paid plans are sold in credits that cover AI and plagiarism scans together — the Personal plan is billed at $167.88 a year and includes 1,200 unified credits, which Copyleaks says covers up to 300,000 words. Schools pay for it separately through their LMS.
Can Copyleaks detect Grammarly?
It can flag writing that was polished with Grammarly's AI features. Copyleaks itself warns that platforms like Grammarly use generative models, so heavily AI-edited human writing can be flagged as potential AI content.
Does Canvas use Copyleaks?
Only if your school has installed it. Copyleaks offers an integration for Canvas as well as D2L, Moodle, Blackboard, Schoology, Edsby and Sakai. Canvas itself has no built-in AI detector.
What is Copyleaks AI Logic?
It is Copyleaks' explanation layer. AI Phrases highlights wording that appears far more often in AI text than in human text, and AI Source Match flags passages that already exist elsewhere online.
Copyleaks vs Turnitin: which do schools use?
Both sell to institutions and both plug into learning platforms. Which one scans your work depends entirely on what your school licensed. The [Copyleaks vs Turnitin comparison](/compare/copyleaks-vs-turnitin) covers the differences.
Will my text be used to train AI?
No. Your text is sent to the model only to produce your result and is never used to train any AI. No content is stored beyond the request.
Does it keep my original meaning?
Yes. Humanit preserves your facts, numbers, names, and citations while changing the phrasing and structure. It never invents new claims.