JustDone AI Detector Review: It Flagged All 10 Human Essays We Tested

JustDone AI Detector was not accurate on the human writing we gave it. Its free box scored 10 of 10 known-human essays at 71% AI or more, with an average of 84.0%, and it scored 9 AI texts at an average of 81.6%. In this sample, a high JustDone score said nothing about who wrote the text.

Here is every score, as JustDone’s result panel printed it:

Look at the bottom of each group. The lowest human essay sat at 71%, and the lowest AI passage sat at 70%. No cutoff could clear all ten students without also clearing all nine AI texts, and even clearing the lowest-scoring student would have cleared one AI passage. That is the opposite of what a detector is for.

If JustDone just gave your own paragraph a number like these, paste the same paragraph into our free AI detector for a second read. HumanizeMyAI’s detector was trained on 15,542 real human passages and reads 28 statistical signals, so it judges your text against how people actually write.

We tested JustDone AI Detector by pasting 19 texts, one scan each, into its free web box with no account, on 1 and 4 November 2026. Ten texts were written by students, for school or for the TOEFL exam, and nine were written by AI. We recorded only JustDone’s headline AI score.

Two texts did not make the table. A fifth ChatGPT answer, which would have been the tenth AI text, hit JustDone’s sign-up wall and never got a score. One more scan, on an essay whose origin we could not confirm, was left out before analysis. JustDone scored it 96% AI, so dropping it made JustDone’s record look better, not worse, but a review built on known-human writing cannot include a text nobody can vouch for.

JustDone flagged all five non-native English essays in our test, at 79% to 100% AI, with an average of 85.8%. One TOEFL essay of 115 words scored a full 100%. The five native student essays fared only a little better, at 71% to 94%.

Non-native writers carry extra risk with detectors, since simpler vocabulary and regular sentence patterns can read as machine-like. Our run did not show JustDone treating those writers worse than native students in any meaningful way, because both groups were flagged across the board. If English is your second language, our guide to AI detection for ESL writers explains which writing habits draw a false flag and how to document your work.

JustDone flagged every AI text it scored in our test: four ChatGPT answers at 78% to 99%, and five AI academic passages at 70% to 91%. Raw ChatGPT output did not slip past it. The problem is that human essays landed in the same range.

A detector that flags everything will catch all the AI it sees, and that alone proves little. What matters is whether a score separates the two kinds of writing, and in this run it did not: the AI texts averaged 81.6%, under the 84.0% the human essays averaged. Our guide to detector accuracy walks through why a catch rate without a false-positive count is only half an answer.

JustDone’s detector page shows a 99,8% accuracy badge above the text box and, further down the same page, figures of 80% overall detection accuracy, 98% on academic texts and a 10.3% error rate (read 4 November 2026). Its own blog post on how detectors work, by Noah Lee and updated 6 July 2026, gives a third figure: roughly 94% in internal testing.

JustDone labels the 80%, 98% and 10.3% figures as independently benchmarked, but the methodology link beside them leads to that same blog post, which names no test set, sample size or outside benchmarker (read 4 November 2026). Read side by side with our run, the gap is wide. A 10.3% error rate would lead you to expect about one wrong call in ten texts; on our ten human essays, JustDone made ten.

The result panel also shows a second score badge that JustDone labels as a double check by another detector. We could not confirm that this badge comes from a live outside check, so we left it out of every number on this page.

JustDone is a real, paid product run by GM Appdev Limited, a company registered in Limassol, Cyprus, according to its detector page (read 4 November 2026). Its detector works and returns a score. Whether that score deserves your trust is a separate question, and our test says no.

A news report points the same way. On 30 March 2026, AFP reported that JustDone AI processed a human-written report about the US-Iran war and concluded it contained “88% AI content” (AFP via France 24). JustDone answered AFP that no AI detector can guarantee 100 percent accuracy. That is true of every detector, and it is why a single high score should never be treated as proof.

JustDone AI Detector lets you scan without an account at first, and then asks you to sign up. In both of our sessions, a sign-up dialog (email or Google) appeared on the 11th scan. The detector page lists the paid plan at $19.99 a month, auto-renewing, and says it handles up to 15,000 words per scan (read 4 November 2026).

The same page sells an estimated Turnitin score as a premium feature. An estimate from an outside tool is not the score Turnitin itself would give your essay. The longest text we scanned was 340 words, so we did not test the 15,000-word claim. Because the plan renews on its own, cancel before the renewal date if you only needed a few scans, and keep the confirmation email in case a charge appears later.

No, not if you wrote the essay yourself. JustDone sells its own AI humanizer next to the detector, and its detector page tells users to reword flagged parts with that humanizer and scan again (read 4 November 2026). Rewriting your own essay to please a detector that scored ten out of ten human essays as AI is the wrong fix. Your words are not the problem.

A humanizer is for a different job: a draft you built with AI help, where you want the final text to read in your own voice. HumanizeMyAI’s humanizer is built for exactly that job, trained on 2,590 real student essays so the rewrite reads like a student wrote it. You can rewrite an AI-assisted draft in your own voice on a free account: four runs of 250 words to try it, with full assignments on a paid plan.

If JustDone says your essay is AI and you wrote it, do not pay to rewrite it and do not panic. Get a second score from a different detector, then gather proof of how you wrote it: version history, notes, outlines and sources. In our test, JustDone’s number would have accused every student.

1. Get a second read. Run the same paragraph through HumanizeMyAI’s free AI checker. Four scans of up to 250 words a day need no account, and a free account gives you 20 a day for longer text.
2. Save your writing trail. Google Docs and Word keep version history. Export it before anything else changes.
3. Ask what tool your teacher used. A JustDone score you ran yourself is not the score your school sees.
4. Prepare your case calmly. Our step-by-step guide on how to show you wrote your own work covers what to bring to the conversation.

JustDone AI Detector is not worth paying for if you need to know whether your own writing will read as human. In our November 2026 run, its free box gave every one of ten human essays a score of 71% AI or higher, and its averages for human and AI text sat within three points of each other.

What students need is a score that holds up against real human writing, and a humanizer that works on AI-assisted drafts without asking you to rewrite your own words. HumanizeMyAI gives you both, the detector and the humanizer, under one account. Start free, and when you need full assignments, compare HumanizeMyAI plans. Before you hand anything in, check your essay on our detector first.