Flux’s trail depends on how you use it
- In ComfyUI: the PNG usually carries the prompt and the workflow as JSON in its text chunks. That is the most revealing trail: it reconstructs your whole process.
- Via API or integrations: the file may come out cleaner, but it is still worth checking EXIF/XMP and possible credentials depending on the service that delivered it.
Because behavior depends on the environment, the checker shows what your particular file contains before you clean it.
How to clean it
1. Upload the image to the checker to see the text chunks (prompt/workflow) and the other metadata. 2. Remove the PNG text chunks and apply /exif / /xmp as needed. 3. Download the file. It is not recompressed: identical pixels (verifiable by hash).
Supported formats: JPEG, PNG, WebP, AVIF, TIFF and HEIC.
What cannot be removed
If your Flux or ComfyUI pipeline inserted an invisible pixel-level watermark, that is not removed: it is not metadata, it is part of the pixels. What we do remove is the prompt, the embedded workflow, EXIF and XMP, which is what usually gives away the origin and the process. Cleaning metadata reduces the file’s trail; it does not make it undetectable.
Privacy
The image is uploaded to our server, processed and deleted after 5 minutes. It is not used for training, we add no watermark, no account is required and the service is free.