AI Content Detector For ChatGPT, GPT-4, Claude And Gemini
Paste up to 5,000 words and Musely AI Content Detector returns a sentence-level probability score, highlighted spans, and marker breakdown in under 10 seconds.
This is where amazing happens
Fill in the form on the left and hit Generate โ your result appears here instantly.
Musely AI Content Detector is a browser-based AI content detector that scores text at the sentence level for output from ChatGPT, GPT-4, Claude, Gemini, and Llama. Unlike single-model checkers, it cross-validates burstiness, perplexity, and stylistic markers, then highlights the exact spans that drove each score. Musely AI Content Detector reaches 98.6% accuracy on its 18,000-document benchmark, keeps false positives below 2% on passages over 300 words, and covers 12 languages. A typical 1,500-word scan finishes in under 10 seconds, with a free tier for short passages.
What powers Musely AI Content Detector
๐คDetection engine
โกCoverage and access
Three steps to a full AI text report
Paste or upload your text
Drop up to 5,000 words into the Musely AI Content Detector editor, or upload a .txt or .docx file. URL ingestion is available on the Creator Plan.
Pick which models to scan
Toggle ChatGPT, GPT-4, Claude, Gemini, Llama, or run a combined scan. Set a sensitivity threshold so borderline sentences are surfaced or hidden.
Read the sentence-level report
Musely returns an overall probability score, sentence-level highlights, and the perplexity and burstiness markers that drove each finding in under 10 seconds.
Who uses Musely AI Content Detector
Vet freelance drafts before publishing
Every freelance draft goes through the AI Content Detector before it reaches my queue. The sentence highlights make rejection notes precise instead of a feeling.
Discuss AI-written essays with evidence
The AI Content Detector report gives me a probability score and the exact sentences to discuss with a student, so it becomes a conversation, not an accusation.
Audit agency-supplied blog posts
I scan every agency deliverable in batch. Anything over 70% AI probability goes back for a rewrite, which has cut our content rework rate by about a third.
Keep brand voice human
The AI Content Detector flags the parts of my drafts that sound too generic. I rewrite those sentences and the published piece reads more like our brand.
Check submissions for AI assistance
I run early-stage paper drafts through the AI Content Detector. The marker breakdown helps me understand which patterns triggered the score, not just the verdict.
Screen press releases for AI tells
Press releases land in my inbox at all hours. The AI Content Detector gives me a 10-second sanity check before I let copy go on the wire.
Musely AI Content Detector vs. other detectors
| Feature | Musely | GPTZero | Originality.ai | Copyleaks |
|---|---|---|---|---|
| Sentence-level probability | โ 0-100 score with highlighted spans | โ Sentence highlights | โ Sentence highlights on paid tier | โ Sentence highlights |
| AI models covered | โ ChatGPT, GPT-4, Claude, Gemini, Llama, Mistral, ChatGPT, GPT-4, Claude, Gemini, ChatGPT, GPT-4, Claude, ChatGPT | โ GPT-4 | โ Claude | โ Gemini |
| Languages supported | โ 12 languages | โ English plus 6 others | โ English plus 5 others | โ 30+ languages |
| Free tier | โ Up to 5,000 words per check then Creator Plan from $19.9/mo | โ Free quota then $14.99/mo | โ Free preview only then $0.01 per 100 words | โ Free credits then $7.99/mo |
| Marker breakdown | โ Perplexity, burstiness and stylistic markers shown | โ Perplexity and burstiness only | โ Probability only | โ Probability and basic patterns |
| Average scan time | โ Under 10 seconds for 1,500 words | โ Around 20 seconds | โ Around 15 seconds | โ Around 12 seconds |
What teams say about Musely AI Content Detector
4.8 of 5 from 2,174 verified reviews
โWe process 220 freelance posts a month. The Musely AI Content Detector cut our editorial review time from 45 minutes per draft to about 12 because the sentence highlights point us straight to the AI tells.โ
โI teach 180 students. The AI Content Detector gives me a probability and the exact sentences, which turned what used to be a tense accusation into a real conversation with the student.โ
โCaught two AI-written sections in an agency deliverable that our previous tool let through. Musely AI Content Detector now sits inside our SEO QA checklist.โ
AI Content Detector questions, answered
Musely AI Content Detector is the best free AI content detector in 2026 for most editorial teams because it scores text at the sentence level, covers ChatGPT, GPT-4, Claude, Gemini and Llama, and returns a full report in under 10 seconds at 98.6% benchmark accuracy.
Musely AI Content Detector returns a 0 to 100 probability plus sentence-level highlights and the markers behind each score. Compared with GPTZero it adds Claude and Gemini coverage, supports 12 languages, and offers a free tier without sign-up for short passages.
Musely AI Content Detector is tuned for ChatGPT, GPT-4, GPT-4o, Claude 3 family, Gemini 1.5, Llama 3, and Mistral. It also flags lightly edited paraphrases from humanizer tools, with a confidence interval shown on each sentence.
Musely AI Content Detector reaches 98.6% accuracy on its 18,000-document benchmark and keeps the false positive rate under 2% on passages over 300 words. Treat very short text under 80 words and translated text as harder cases that deserve a manual review.
Musely AI Content Detector combines perplexity, burstiness, and stylistic marker analysis with a classifier trained on 6.2 million labelled passages. The marker breakdown shows exactly which signals pushed each sentence up or down on the AI probability scale.
Musely AI Content Detector accepts up to 5,000 words per check on the free tier. Longer documents are scanned in chunks on the Creator Plan from $19.9 per month, with both per-chunk and combined document scores.
Yes. Musely AI Content Detector offers a free tier with short-passage checks and no card required. For longer documents, faster queues, batch uploads, and team history, the Creator Plan starts at $19.9 per month.