This free AI detector for teachers checks a piece of student writing and returns an AI probability score, a verdict of likely AI, likely human or uncertain, the reasons behind it, and the stock phrases in the text that often show up in AI writing. It is free, needs no signup, and is built for a quick first look at an essay or short answer. No AI detector is fully reliable, so treat the result as one signal to follow up on, never as proof of misconduct.
How to check student work with the AI detector for teachers
- Optionally choose the assignment type (essay, research paper, short answer, lab report, book report, code submission or discussion post) and enter the subject or topic.
- Paste the student's text. At least 50 characters is required and 100 words or more gives a more meaningful read. The box holds up to 3,000 characters.
- Click Check for AI Content.
- Read the AI probability, the verdict and the key indicators listed under it.
- If any stock expressions are found, scroll to Suspicious phrases to see them highlighted in the text, and use Print report if you want a copy for your notes.
- Follow up with the student before drawing any conclusion.
What the result shows
AI probability and verdict
A percentage from 0 to 100 and one of three labels: Likely AI-Generated, Likely Human-Written or Uncertain. The score is an AI language model's judgement of the writing style, based on signs such as repetitive phrasing, formulaic transitions, hedging, generic examples, a lack of personal voice and unusually polished grammar. Giving the assignment type and topic lets the model judge the text against what that kind of work normally looks like.
Key indicators
A short list of the specific reasons behind the score. These are often more useful than the number, because they point to passages you can discuss with the student.
Reading level and suspicious phrases
The tool also shows the reading grade of the text and highlights stock phrases such as "it is important to note", "delve into", "in conclusion" and "furthermore". These phrases are common in AI output, but many students were taught to write them, so a highlight is a reason to look closer, not evidence on its own.
How reliable is an AI detector for teachers?
Not reliable enough to decide a case. Every AI detector, free or paid, produces false positives and false negatives. Writing by English language learners, students who follow a strict essay template, and short or highly technical answers are more likely to be flagged wrongly. Text that was generated and then edited, or run through a paraphrasing tool, is often missed. This tool also uses a general AI model rather than a classifier trained and tested on student essays, and it reads roughly the first 1,800 characters of what you paste, so check long work in sections.
That is why the result should never be the sole basis for an academic misconduct decision. Most schools' integrity policies expect more than a detector score, and students deserve a chance to explain their work.
What to do when work is flagged
Use the score as the start of a conversation, not the end of one. Practical steps many educators use:
- Compare the flagged work with the student's earlier writing and in-class work for voice, vocabulary and typical errors.
- Ask to see notes, outlines, drafts or the document's version history.
- Have a short conversation where the student explains their argument, sources or a key paragraph in their own words.
- Check citations: invented or mismatched references are a stronger sign than any phrase list.
- Follow your school's academic integrity policy and record what you found, not just the score.
For future assignments, in-class drafts, personal reflection prompts and staged submissions make AI misuse harder and authentic work easier to recognise.
Student privacy
The text you paste is sent to an AI model to be analysed and is not saved to an account, because there is no account. Even so, remove student names, ID numbers and other personal details before pasting, and follow your institution's rules on sharing student work with online tools.
AI detector for teachers FAQ
What is the best AI detector for teachers?
There is no detector accurate enough to rely on alone, and published tests regularly show both missed AI text and wrongly flagged human writing. The best approach is a detector for a quick first look combined with drafts, version history and a conversation with the student.
Is this AI detector for teachers free?
Yes. It is free with no signup, no account and no limit on checks.
Can I use the score as proof a student cheated?
No. The score is a probability estimate that can be wrong. Do not base an academic misconduct decision on it alone; gather other evidence and give the student a chance to explain.
Why was a student's own writing flagged as AI?
Clear, formal, formulaic writing looks similar to AI output, and phrases like "in conclusion" or "furthermore" are taught in many classrooms. Non-native writers are flagged more often for the same reason.
Does it work for code submissions?
You can select Code Submission and paste code, but the phrase checks and style signals are designed for prose, so results on code are less meaningful.
How much text can I check at once?
Up to 3,000 characters fit in the box, and the analysis focuses on roughly the first 1,800. For a long essay, check the introduction and a body section separately.