# SupWriter AI Detector

SupWriter's AI detector classifies text as AI-generated or human-written and reports verdicts from 12 popular detection engines plus a sentence-level breakdown. Use it to verify your own work before submission, audit content from contractors, or understand what specific detectors will flag.

Live tool: [supwriter.com/ai-detector](https://supwriter.com/ai-detector).

## What it does

- Returns an overall AI-vs-human probability score for the submitted text.
- Reports per-detector verdicts across 12 engines: Turnitin, GPTZero, OpenAI, Claude, Gemini, Grok, Grammarly, Crossplag, Copyleaks, QuillBot, Sapling, ZeroGPT.
- Highlights individual sentences that look AI-generated, with confidence levels.
- Pairs with the [AI humanizer](https://supwriter.com/ai-humanizer.md) for a detect → rewrite → re-detect workflow.

## How to use

1. Paste text into the editor at [supwriter.com/ai-detector](https://supwriter.com/ai-detector) or call the API endpoint.
2. Submit. Results appear within a few seconds for typical-length text.
3. Review the per-detector verdicts and the sentence-level highlights.
4. If flagged, run the same text through the humanizer and re-check.

## API

- Endpoint: `POST /api/aidetect/v2`
- OpenAPI: [/.well-known/openapi/ai-detector.yaml](https://supwriter.com/.well-known/openapi/ai-detector.yaml)
- Auth: Supabase-issued JWT as `Authorization: Bearer <token>`.

## Why per-detector verdicts matter

Different detectors weight signals differently. A draft that passes GPTZero may still get flagged by Turnitin. Reporting all 12 verdicts simultaneously lets writers and editors target the specific tools they care about (e.g., Turnitin for academic submissions, Originality.AI for content marketing).

## Pricing

The core detector verdict is included on all paid plans without per-word credit charges. See [pricing.md](https://supwriter.com/pricing.md).

## Related

- [AI humanizer](https://supwriter.com/ai-humanizer.md) — rewrite text that gets flagged.
- [Free AI detector blog post](https://supwriter.com/blog/best-ai-detector-tools-2025) — comparison of detection tools.
- [How AI detection works](https://supwriter.com/blog/how-does-ai-detection-work)