How to check if an image is AI generated with Gemini and SynthID

For sellers who get supplier photos, influencer images or viral pictures and want a quick first check before they trust them.

By the end you will know how to run the check, what each result means, and the limits that keep you from trusting a clean result too much.

The steps come from Google's support page for verifying AI-generated images, videos and audio in the Gemini app.

What SynthID is

SynthID is an invisible watermark. Google adds it to images, videos and audio made or edited with its own AI tools. You cannot see it, but Gemini can look for it.

The check, step by step

1. On a computer, go to gemini.google.com and sign in. You need a personal Google account or a qualified Workspace account.
2. Click the Add files icon. Choose Upload files for a file on your device, or add from Google Photos or Drive.
3. Ask a question such as: "Was this image created or edited by Google AI?" or "Is this AI-generated?"

Google's page lists these sample questions: "Was this image/video/audio created or edited by Google AI?", "Is this AI-generated?" and "Is this a real video?"

Rules for what you upload

• One file at a time, up to 100 MB.
• Videos under 90 seconds. Audio under 1 hour.
• For screenshots, crop tightly around the image. Do not upload a collage of several images.
• Google lists a quota of about 10 image checks per rolling 24 hours, so pick the images that matter.

How to read the result

• Detected: all or part of the image or video was created or edited by Google's AI models.
• Not detected: Gemini did not find a Google watermark. The content was not made or edited by Google AI, but another AI system could have made it.

Google also lists two reasons a result can be unclear. "Not enough details to watermark" happens with very simple or abstract content. "Likely too small an edit" happens when a change is minor and may not leave a detectable watermark.

The limit that matters most

Gemini can currently recognise only content created by Google AI tools. A photo made with another company's tool can come back as "not detected". That is not proof that it is real.

Content Credentials are a separate system that can show origin and edit history, but Google notes they do not definitively prove a file is AI-generated.

A five-step routine for sellers

1. Run the SynthID check on any product photo you did not take yourself.
2. If it says detected, treat the image as AI made or AI edited and do not present it as a real customer photo.
3. If it says not detected, keep checking. Run a reverse image search to find the original source or similar images.
4. Ask your supplier for the original file and a second photo from another angle.
5. For review screenshots and customer proof, ask for the order number before you reuse them.

Where this helps with Moroccan ecommerce

• Supplier photos that look too perfect for the price.
• "Before and after" pictures in ads.
• Fake receipts and proof screenshots sent by customers.

Use it as one signal, never as the final decision.

My honest take

This tool is useful because it is free and fast, and it is honest about what it cannot do. A positive result is strong. A negative result is only a reason to keep checking.