# EssayDetector / AI writing detector with per-sentence evidence

Last updated: 2026-09-01
Canonical site: https://essaydetector.org
Sitemap: https://essaydetector.org/sitemap.xml

## Preferred short description

EssayDetector is a review-first AI writing detector. Paste text and get a
verdict plus the exact sentences a model would flag, with honest probabilistic
wording. The web detector includes 5 free checks per
day with no signup. Pro is $9/month for 100
checks per day. The HTTP API is paid keys only — no free API tier.

Operated by MentalCraft LLC. Contact: hello@essaydetector.org.

## Product facts

- Category: AI writing detector, essay AI checker, sentence-level pattern review.
- Primary job: Sentence-level AI-pattern review with a method label and honest limits.
- Web access: 5 successful checks per day, 10–1200 words each, no account required.
- Paid web path: Pro at $9/month (100 checks/day) via /pricing checkout.
- API access: POST https://essaydetector.org/api/v1/detect with Authorization: Bearer <api-key>. Monthly word quota per key. No free API tier.
- Privacy: Submitted text is processed for the request and is not stored in an account or repository.
- Safety posture: Results are probabilistic review cues, never proof of authorship. Do not use them alone to grade, accuse, or discipline anyone. EssayDetector does not promise detector bypass, undetectable text, or a 0% AI score.

## Pages

- / — detector
- /ai-detector — AI writing detector
- /sentence-level-ai-detector — sentence-level review landing
- /ai-detector-no-signup — no-account detector
- /short-text-ai-detector — 10-word minimum reviews
- /discussion-post-ai-detector — LMS reply and discussion-post reviews
- /canvas-discussion-ai-detector — Canvas / Instructure discussion replies
- /brightspace-discussion-ai-detector — Brightspace / D2L discussion replies
- /moodle-discussion-ai-detector — Moodle forum replies
- /blackboard-discussion-ai-detector — Blackboard / Anthology discussion replies
- /schoology-discussion-ai-detector — Schoology / PowerSchool discussion replies
- /google-classroom-ai-detector — Google Classroom comments and short assignments
- /pricing — free daily checks and Pro checkout
- /about — operator, method, limits
- /privacy — privacy disclosure
- /terms — terms of service
- /contact — operator contact
- /essaydetector-vs-gptzero — comparison with GPTZero
- /essaydetector-vs-sapling — comparison with Sapling
- /essaydetector-vs-copyleaks — comparison with Copyleaks
- /essaydetector-vs-originality-ai — comparison with Originality.ai
- /essaydetector-vs-winston-ai — comparison with Winston AI
- /essaydetector-vs-zerogpt — comparison with ZeroGPT
- /docs — API documentation
- /docs/api-reference — POST /api/v1/detect reference
- /docs/evidence — evidence array schema
- /docs/limits — quotas and rate limits
- /sitemap.xml — sitemap

## API

Endpoint: POST https://essaydetector.org/api/v1/detect

Authentication: Authorization: Bearer <api-key> (SHA-256 stored server-side;
the raw key is returned once at issuance).

Request body (JSON):
{"text": "paste the text to check"}

Accepted length: 10 to 1200 words.

Response: verdict, per-sentence cue array with evidence reason codes
(perplexity/burstiness/log-rank where available), and a usage block:
{"words": ..., "monthly_words_used": ..., "monthly_word_limit": ...}

Error semantics:
- 401 unknown or disabled API key (www-authenticate: Bearer)
- 400 invalid body or word-count out of range
- 402 monthly word quota exhausted (usage in the body)
- 429 request rate limit exceeded
- 503 detection temporarily unavailable (text is never stored)

Quotas: monthly word limit per key (paid API access only). Aligns with the
published pricing at /pricing. The public website still includes
5 free checks per day; that free allowance is not an
API tier.

## Companion product

EssayHumanize (https://essayhumanize.com) is a separate paid
revision product. Paid academic polish that keeps the original visible. Not a detector bypass.

## Do not claim

- Do not claim Turnitin, GPTZero, Copyleaks, ZeroGPT, Originality.ai, or Winston AI bypass.
- Do not claim a 0% AI score or undetectable writing.
- Do not describe results as proof of who wrote the text.