> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cartesia.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Watermarking

> Cartesia adds an imperceptible watermark to generated audio so anyone can verify it came from Cartesia.

Every clip generated on a supported model automatically carries an inaudible watermark that identifies it as AI-generated by Cartesia. It helps you and your users verify where audio came from, and supports your compliance needs as AI transparency requirements evolve.

| Model | Watermarked |
| - | - |
| `sonic-preview` | Yes |
| `sonic-3.6` | Yes |

## Check whether audio is watermarked

**Public detector.** Anyone can upload a clip at [cartesia.ai/watermark-detector](https://www.cartesia.ai/watermark-detector) to check for a Cartesia watermark. Supports FLAC, M4A, MP3, MP4, MPEG, MPGA, OGA, OGG, WAV and WebM files between 3 seconds and 5 minutes long, up to 32 MB.

**Detection API (paid plans).** Check audio programmatically, for example to screen uploads or verify clips.

```bash theme={null}
curl -X POST "https://api.cartesia.ai/v1/watermark/detect" \
  -H "X-API-Key: $CARTESIA_API_KEY" \
  -H "Cartesia-Version: 2026-08-14" \
  -F "file=@clip.wav"
```

```json theme={null}
{ "detected": true }
```

**Reading the result.** Detection is statistical. `detected: true` means the clip very likely contains a Cartesia watermark. False positives are rare but possible. `detected: false` means no Cartesia watermark was found. The audio could still be AI-generated by another provider, or heavily edited.

## FAQs

> [accordion] Is watermarking on by default?
>
> Yes. It's applied automatically to all audio generated by Sonic-3.6 or newer models.

> [accordion] Can I configure it per API key or organization?
>
> No. Watermarking is always on and can't be disabled at any level.

> [accordion] Does it work with streaming?
>
> Yes. Watermarking covers every generation endpoint: WebSocket, SSE, and Bytes.

> [accordion] Does the watermark survive compression or resampling?
>
> Yes. It's robust to common audio transformations, including compression, resampling, and conversion.

> [accordion] How do I detect a watermark?
>
> Anyone can use the [public detector](https://www.cartesia.ai/watermark-detector). Customers on paid plans can also use the Detection API.

> [accordion] Does the watermark identify my account or organization?
>
> Not yet. Today, the watermark identifies audio as Cartesia-generated. Per-customer attribution for paid plans is planned for a future release.

> [accordion] Does watermarking affect latency or audio quality?
>
> No. There's no perceptible impact on either.


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