Image Tools
Gemini & Nano Banana Image Detector
Check whether an image came from Gemini or Nano Banana: read its Content Credentials and metadata in your browser, run a pixel-level AI scan, then confirm the SynthID watermark with Google's own detector.
The signals Google embeds
Content Credentials signed by Google
Gemini image output carries a C2PA manifest signed by Google LLC with the app 'Google Media Processing Services' — Nano Banana Pro images in the Gemini app, Vertex AI and Google Ads have carried C2PA since November 2025.
An invisible SynthID watermark
Every Gemini-generated image gets a SynthID watermark embedded in the pixels at generation time. It is proprietary — only Google's SynthID Detector can read it.
A visible Gemini watermark
Images downloaded from the Gemini app may show a small visible mark. It sits in a corner and can be cropped or covered — its absence proves nothing.
Google image models and their signals
The naming changed with each release — Gemini 2.5 Flash Image is 'Nano Banana', Gemini 3.1 Flash Image is 'Nano Banana 2', and Gemini 3 Pro Image is 'Nano Banana Pro'.
| SynthID watermark | Content Credentials | |
|---|---|---|
| Nano Banana (Gemini 2.5 Flash Image) | Yes | Yes — signed by Google LLC |
| Nano Banana 2 (Gemini 3.1 Flash Image) | Yes | Yes — signed by Google LLC |
| Nano Banana Pro (Gemini 3 Pro Image) | Yes | Yes — API, Vertex AI and Google Ads outputs |
| Imagen | Yes | Yes — signed by Google LLC |
Screenshots, re-saves and most social uploads strip Content Credentials — the watermark often survives them.
How to confirm with Google
Run the local check first
Drop the image in above — a Google-signed credential is already strong evidence it came from a Google AI product.
Open Google's SynthID Detector
Upload the file at synthid.com (Google sign-in required) — it reads the invisible SynthID watermark directly.
Or ask the Gemini app
Upload the image to Gemini and ask 'Was this created with Google AI?' — Gemini checks for a SynthID watermark in the file.
Read a 'no watermark' result carefully
Google's detector may report too few details to watermark on very small edits or simple images — that is not proof the image is human-made.
Where it helps
Identifying Nano Banana images
Nano Banana images went viral fast — check whether a suspicious portrait or product shot came from Gemini's image model.
Verifying AI labels on platforms
Some platforms label Google AI content — a Google-signed Content Credentials manifest is the checkable version of that claim.
Checking ads and AI-edited product shots
Google Ads image outputs carry C2PA — a signed manifest tells you the image was generated for a campaign.
Limits
Screenshots lose the credential
A screenshot of a Gemini image keeps the watermark but drops the C2PA manifest — the browser check then shows 'not found' even though the image is AI.
Re-saves can strip metadata
Apps that re-encode or compress an image may remove credentials and metadata without touching the pixels.
A cropped visible watermark proves nothing
The visible Gemini mark can be cropped out or covered by a logo — never treat its absence as evidence.
Gemini Image Detector FAQ
Does a cropped Gemini watermark mean it's not AI?
No. The visible watermark sits in a corner and is easy to crop or cover. The invisible SynthID watermark is what matters — only Google's detector can read it.
Why does my Gemini image show no Content Credentials?
Screenshots, re-saves in editors, and most social media uploads strip the C2PA manifest. Try the original file, or run the pixel scan and confirm with Google's detector.
Can this tool read the SynthID watermark?
No — SynthID is proprietary to Google. This page reads the public signals around it and points you to Google's official detector for watermark confirmation.
Is the check free?
The credential and metadata checks are free and run in your browser. The pixel-level AI scan requires sign-in and credits.
Which Google models does this cover?
Gemini image models — Nano Banana (Gemini 2.5 Flash Image), Nano Banana 2 (Gemini 3.1 Flash Image) and Nano Banana Pro (Gemini 3 Pro Image) — plus Imagen and Veo, which carry the same signals.
Check a Gemini image
Read the file's credentials and metadata in your browser — then confirm the watermark with Google.