Log inGet started
All tools

AI Content Detector

AI
Detect AI-generated text (ChatGPT / Claude / Gemini) in any PDF. Surfaces formulaic structure, AI-typical phrasing, register shifts. Honest heuristic — not a courtroom-grade scan.
New here? This AI tool is free to try.
Create an account and get 5 credits — no card, no daily limit.
Create free accountSign in

What you'll get: a heuristic AI-content audit — surfaces well-documented LLM stylistic fingerprints (formulaic openers, hedging overuse, em-dash patterns, register-too-polished, three-item rhetoric, transitional clichés). Honest caveat: heuristic only, not a courtroom-grade classifier — false positives and negatives possible. For another use, try AI · Improve Writing.

Loading tool…
Private & secure
AI tools process your PDF in memory, send only the extracted text to the model, and discard everything immediately. No file is persisted on our servers.
No watermarks
Clean output, no branding, no daily limits.
Pay only for what you use
Purchased credits never expire. Cancel anytime.

Why people use AI Content Detector

Detection of AI-generated text (ChatGPT / Claude / Gemini / Llama) is heuristic, not exact. The detector surfaces formulaic structure, AI-typical phrasing, register shifts — signals that suggest LLM authorship — with confidence scores. This is a flag-for-review tool, not courtroom-grade evidence.

Education — assignments, theses
Teachers and TAs running submitted assignments through the detector to flag suspicious essays for human review. Detection accuracy on student writing varies by grade level — high-school work flags more reliably than graduate work.
Hiring — cover letters, written assessments
Take-home assessments and cover letters increasingly come from LLMs. The detector flags candidates whose writing samples match LLM signatures, prompting a follow-up conversation rather than an automatic disqualification.
Editorial — submitted articles, freelance work
Editors handling pitches and submissions screen for LLM-generated content. Useful for outlets where human authorship is part of the value proposition (memoir, opinion, voice-driven journalism).
Marketing — vendor-supplied copy authenticity
When agencies or freelance writers deliver content, the detector previews whether the work was likely human-written or AI-generated. Useful for shops paying premium rates for human authorship.
Quality control on translated content
Some translation services secretly use LLM translation. The detector surfaces the LLM-typical signature in the output even when the prose is grammatically clean — helpful for buyers verifying they got what they paid for.

How AI Content Detector works

Three steps. Sign in to run, zero retention — files never persisted on our servers.

  1. STEP 1
    Drop the PDF
    PDF up to 50 MB. Works on essays, articles, reports, cover letters, theses. Plain prose works best; heavy code or technical notation isn’t the target use case.
  2. STEP 2
    We score each passage
    Server-side text extraction, then per-passage scoring against signatures of AI-typical phrasing, sentence-length distribution, register-shift patterns, and uniformity metrics. Different LLM families have different fingerprints; the detector tries to match the strongest.
  3. STEP 3
    Get a flagged report
    Output: overall confidence (0–100% AI-likely), per-passage breakdown with the flagged sentences highlighted, suspected source family (GPT-4-class / Claude-class / Gemini-class). Treat this as a flag-for-review, not a verdict.

What makes pdfcraft ai different

  • Citations on every claim
    Every AI summary, answer, and translation links back to the page it came from. You can verify the source before relying on the output. Hallucination is bounded, not blind.
  • Pay only for what you use
    No subscription. Purchased credits never expire. Cancel anytime. Cost shown before you run — exact credit amount appears after upload.
  • Multi-provider routing, no vendor lock-in
    We balance multiple AI providers per call to optimise cost and quality. If one has an outage, the next call automatically tries another. You're not bound to a single vendor's pricing or downtime.
  • Zero retention by design
    Your PDF lives in memory only as long as the AI call needs it, then it's discarded — nothing is persisted to our servers. We don't fine-tune models on your data. Verifiable in your dashboard's audit log.
  • Honest about model limits
    When a doc exceeds the model's context window we surface that the output was truncated (we render result.wasTruncated in every AI tool's UI). When a number can't be verified from the source we flag it. No silent failures.

Frequently asked questions

What’s the false-positive rate?
Significant — we don’t publish a fixed FP rate because it varies by genre and writing skill. Highly polished human writers (professional editors, technical writers) are sometimes flagged because polish itself looks LLM-uniform. Treat the score as a probabilistic signal, not a verdict.
Can it tell ChatGPT from Claude from Gemini?
Sometimes — each LLM family has subtly different signatures (vocabulary preferences, sentence-length distributions). Confidence on the family-attribution is lower than confidence on the human-vs-AI binary. For the family attribution, treat as best-guess only.
What about content that’s been edited after AI generation?
Heavy human editing (rewriting paragraphs, restructuring sections) blurs the signature significantly. Light editing (typo fixes, minor word swaps) typically isn’t enough to evade detection. We err on the side of false negatives here.
Can this be used for academic-misconduct accusations?
Not on its own. The output is “AI-likely with X% confidence” — that’s flag-for-conversation, not proof. Academic misconduct cases require corroborating evidence (prompt logs, draft history, oral examination). The detector accelerates triage, not adjudication.
What’s the credit cost?
3 credits per doc. Cost is fixed regardless of doc size.
Privacy?
Document sent to inference provider, not stored. For sensitive content (anonymous student submissions, confidential editorial pitches), redact identifying metadata first via Redact PDF before running the detection.

Need to rewrite content to avoid detection?

AI Paraphrase rewrites while preserving meaning — useful for content that flagged AI but is fundamentally human work the writer wants to harmonize. NOT useful for AI-generated work the writer is trying to disguise (and we don’t recommend that workflow).

Try AI Paraphrase

Related PDF tools

Other tools in the AI category — built on the same private, in-browser pipeline.

We use a first-party cookie to keep you signed in. Product analytics (Google Analytics 4, Microsoft Clarity) are optional and only load if you accept. You can change this any time on the cookies page.
Customize