# SynthIDDetector.org — full reference

SynthIDDetector.org answers one question: "Was this image made with Google AI, and does it carry a SynthID watermark?" It is an independent tool and is not affiliated with, endorsed by, or sponsored by Google or Google DeepMind. SynthID is a trademark of Google LLC.

## Honest capability boundary

The SynthID watermark is proprietary — only Google's own detector (https://synthid.com) can read it. SynthIDDetector.org never claims to decode SynthID. Instead it checks three public signals:

1. **Content Credentials (C2PA)** — read in the browser. Google signs Gemini, Nano Banana, Imagen and Veo output with C2PA ("Google LLC", app "Google Media Processing Services"). The signed manifest declares AI creation (`digitalSourceType: trainedAlgorithmicMedia`) and can declare that a SynthID watermark is present. A valid Google signature is strong evidence the file came from Google AI.
2. **AI metadata** — read in the browser: IPTC `DigitalSourceType`, XMP `CreatorTool`, EXIF `Software`, PNG text chunks and generator notes.
3. **Pixel-level AI scan** (sign-in, credits) — pixel forensics that ignore metadata, so they still work on screenshots and social re-uploads where credentials were stripped. The scan returns an AI probability and, when available, the likely generator family (Google Imagen / Nano Banana, GPT image, Midjourney, Flux, Stable Diffusion, Firefly, Seedream and similar).

When signals point to Google, the tool tells the user how to confirm the watermark in Google's SynthID Detector or the Gemini app.

"Nothing found" never means "real": files stripped of credentials produce empty results.

## Pages

- https://synthiddetector.org/ — the detector tool (image)
- https://synthiddetector.org/ai-image-detector — pixel-level AI image scan that ignores stripped metadata
- https://synthiddetector.org/gemini-image-detector — signals Google embeds in Gemini / Nano Banana output
- https://synthiddetector.org/c2pa-checker — free in-browser C2PA credential reader (signer, app, actions, validation)
- https://synthiddetector.org/what-is-synthid — guide to Google's SynthID watermark, coverage, limits, sources
- https://synthiddetector.org/pricing — plans and credits

## Inputs and limits

- Images: JPG, PNG or WebP up to 10 MB. Paste an image file, drag and drop, or click to browse. Paste-by-URL will return via a server proxy (browser fetches to arbitrary hosts are CORS-blocked).
- The free credential and metadata checks run entirely in the browser — the file is not uploaded.
- The pixel scan uploads the file for analysis and requires a signed-in account; it consumes 5 credits per image scan (the cost is shown before the scan runs).
- Video (MP4/MOV up to 50 MB, 60 s) and audio checks are planned for a later version.

## Status

- Detection pipeline status: credential, metadata and image pixel scans are live; video pixel scanning is planned.

## Coverage by AI source

| Source | Content Credentials | SynthID watermark | Pixel AI scan |
|---|---|---|---|
| Google Gemini / Nano Banana / Imagen | Signed by Google | Yes (verify in Google's detector) | Covered |
| Google Veo (video) | Signed by Google | Yes | Planned (video scan) |
| OpenAI ChatGPT images | C2PA present | Yes (Google's detector also reads some partners) | Covered |
| Adobe Firefly | C2PA present | No | Covered |
| Midjourney | No | No | Covered |
| Local Stable Diffusion / Flux | No | No | Covered |

## Languages

English, 简体中文, Русский, Deutsch, Français, 日本語, 한국어, Español, Português, Türkçe.

## Contact

- support@synthiddetector.org