See Exactly What Sounds Off
Every sentence gets its own AI-likelihood score and the flagged ones are highlighted inline, so you know which lines to fix — not just an overall number.
AI Detector with Sentence-Level Scores
See how AI-like your text reads, sentence by sentence — then humanize the flagged lines in one click.
Original text
PDF, DOCX, TXT, MD · up to 6,000 words
Score + sentence highlights · free without an account — the first 250 words are checked
0 / 6,000 words
AI detection report
—% of this text appears to be AI-generated
ZeroTell AI Detector · sentence-level scores · a signal, not proof. Free checks score the first 250 words.
Write Smarter, Not Just Safer
AI detectors are everywhere now. Know your score before a school, editor, or client does.
Get a Full Detection Report
One overall score for the whole text plus a score for each sentence, from the ZeroTell AI Detector. Read it as a signal for where to look, not as a verdict.
Rewrite to Sound Human in One Click
Open your checked text in the AI Humanizer with one click, review the rewrite, make final edits, and drop it back into your essay or article.
Why Use an AI Detector?
1
AI writing shows up everywhere now — essays, articles, reports, emails, resumes. The catch is that schools, editors, and clients increasingly run those same drafts through AI detectors before they accept them.
2
A free AI checker lets you see that score first. Paste your draft, run a check, read the sentence-level signals, and humanize the sections that sound robotic or too predictable — before anyone else does.
3
Detection is never perfect, but it points you to the sections worth a second look before you submit or publish.
Check and Humanize in One Workflow
A score alone doesn't fix anything. ZeroTell lets you detect, review, and improve AI-like writing in one place.
Use it to:
- ✓Detect AI text across essays, papers, articles, reports, and documents.
- ✓Judge tone — see whether the writing reads human or machine-made.
- ✓Review sentence by sentence with a score for every sentence.
- ✓Humanize flagged text — one click opens it in the AI Humanizer.
Everything You Need to Detect AI Content
One Score, Sentence by Sentence
The ZeroTell AI Detector scores the whole text and every sentence in it, so a high number always comes with the lines that caused it.
Free Check, No Sign-Up
Paste your text without an account: a free check scores the first 250 words sentence by sentence and explains why the first flagged sentence stood out. A Pro plan checks the whole text (up to 15,000 words), explains every flagged sentence and lets you rewrite them one by one.
Built for Modern AI Writing
It looks for writing patterns common to large language models such as ChatGPT, Claude and Gemini — predictable phrasing, uniform rhythm, generic wording.
What Is an AI Detector?
An AI detector — also called an AI checker or AI content detector — analyzes writing patterns to estimate whether text was generated or heavily assisted by AI.
It looks for signals like predictable phrasing, repetitive structure, generic wording, and the sentence-level patterns common in machine-written text.
Use it on essays, papers, articles, reports, resumes, and documents before you submit or publish.
An AI Detector for Every Kind of Writing
Check academic work, professional drafts, and long documents before you submit, publish, or share.
For Academic Writing
Check essays, term papers, research drafts, assignments, and personal statements before submission — and flag sections that need clearer, more natural wording.
For Articles & Client Work
Scan blog drafts, newsletters, freelance deliverables, and marketing copy for AI patterns before you send or publish.
For Resumes & Professional Docs
Review resumes, cover letters, and business reports to make sure your writing reads personal, specific, and human.
For PDF, Word & TXT Files
Upload a PDF, Word (.docx), TXT or Markdown file — or drag it onto the box — and review the whole draft at once. Scanned PDFs without a text layer can't be read.
For Long Documents
Pro plan scans check up to 15,000 words at once — a full paper or report. Free checks score the first 250 words.
AI Detector vs AI Humanizer
A detector and a humanizer work as a pair but solve different problems. Detect first to see whether your text sounds AI-made, then humanize the sections that need it.
| AI Detector | AI Humanizer | |
|---|---|---|
| What it does | Checks whether your text reads AI-generated, robotic, or overly predictable. | Rewrites AI-like text into natural, readable, human-sounding writing. |
| When to use it | Before submitting or publishing, to find sections worth reviewing. | After detection, to improve wording, flow, and tone. |
Best workflow: check the draft first, read the report, then humanize what sounds too polished.
AI Detector vs Plagiarism Checker
These are not the same tool. One looks for AI writing patterns; the other looks for text that matches existing sources.
| AI Detector | Plagiarism Checker | |
|---|---|---|
| What it checks | Whether text was generated or heavily assisted by AI. | Whether text matches or closely resembles existing sources. |
| What it can't tell you | Whether the text was copied from somewhere. | Whether a human or an AI wrote it. |
Text can be original yet AI-written — or copied yet fully human. For serious work, both checks help.
AI Detection Is a Signal, Not Final Proof
No AI detector can prove with certainty whether a human or an AI wrote a given text.
Results shift with length, topic, style, and how much AI help was used — short passages are harder to judge than full essays.
Treat detection as a way to spot sections worth reviewing. For academic or hiring decisions, pair it with human judgment and a clear policy.
Who Uses ZeroTell?
Students
Run a check before you submit and revise the sentences that read machine-made while there's still time.
Educators
Use sentence-level scores as a starting point for a conversation — never as proof on their own.
Writers & Bloggers
Scan articles before publishing and rework passages that sound generic or over-polished.
Freelancers
Check every deliverable before it reaches a client — more of them are running detectors themselves.
What Makes ZeroTell Different?
Check and humanize in one place
Detect AI text and rewrite flagged writing without switching tools.
Built for real drafts
Works on essays, papers, reports, resumes, articles, and long documents.
Sentence-level feedback
Pinpoint the exact lines that read AI-made, repetitive, or over-polished.
Fits your writing flow
Pair the detector with the humanizer and paraphraser to review and rewrite faster.
AI Detector FAQs
Is the AI Detector free?
Yes, to start. Without a plan — signed in or not — you get a few free checks a day. A free check scores the first 250 words of your text sentence by sentence and explains why the first flagged sentence stood out. Full checks score the whole text (up to 15,000 words), explain every flagged sentence, let you rewrite one and re-check. They are included in the Pro plans* (*fair use: up to 100 scans a day); without a plan, credits you already have pay for a full check (1 credit each).
What does the Advanced scan add?
An Advanced scan (included in the Pro plans*, *fair use applies) adds a paragraph-by-paragraph breakdown and a short note on why each flagged sentence reads as AI-like — stock phrases, rhythm that matches the sentences around it, generic wording. These notes describe writing patterns; they are not proof of how a text was written.
How does an AI detector work?
It analyzes writing patterns — predictable phrasing, repetitive structure, generic wording — to estimate whether text was generated or heavily assisted by AI, and reports the signal sentence by sentence.
Are AI detectors accurate?
They're helpful but not perfect. Results vary with length, topic, style, and the model used. Treat the score as a review signal, not final proof.
Can AI detectors be wrong?
Yes — both false positives and false negatives happen. Human writing can be flagged, and AI text can slip through. For real decisions, combine detection with human judgment — a score alone is not proof that someone cheated. Our Academic Integrity page explains how we think results should be used.
Can I use it for essays and papers?
Yes. Check essays, papers, research drafts, and assignments before submitting to find sections that sound AI-made, repetitive, or over-polished.
Can I check PDF, Word, or long documents?
Yes. Upload a PDF, Word (.docx), TXT or Markdown file up to 10 MB, or paste the text. One scan takes 80 to 15,000 words (a free check scores the first 250). Scanned PDFs that are only images can't be read — paste the text instead. Your file is only used to extract the text and is not stored.
Which detector does ZeroTell use?
The ZeroTell AI Detector. We don't run your text through other companies' detectors, and the score is not a prediction of what any specific school or publisher tool will say. If another detection engine is ever added, the report lists it by name with its own score — never as a blended number.
Does it work on my phone?
Yes. ZeroTell runs in mobile browsers — paste text, check for AI, and read your report from your phone. No app download needed.
Ready to Run an AI Check on Your Text?
Paste a draft or upload a file and see which sentences read as AI-generated.
Detect AI — Free, No Sign-Up✓ Sentence-level scores✓ PDF, DOCX & TXT up to 15,000 words✓ No credit card required