ChatGPT watermark detector
Check text for an OpenAI provenance signal — and see clearly what can be verified.
Your text
0 words3,000 words per free check
About this check
The honest state of OpenAI text provenance
OpenAI has described text watermarking research but has not released a public verifier. There is therefore no way for any third-party tool to confirm that a given text came from ChatGPT. Tools that claim otherwise are running a style-based classifier and presenting its guess as a finding.
What we do check
The OpenAI adapter reports 'Not verifiable'. Alongside it, the invisible-character check runs for real and will find embedded markers if any are present — including ones added by other tools in the chain between generation and you.
Images are different
OpenAI publishes C2PA Content Credentials on images from its image models. Those are signed and can actually be read. If you have an image rather than text, the image checker will find the manifest if it is still intact.