Every image you save from AUTOMATIC1111 or ComfyUI carries your full recipe. Stable Diffusion WebUI embeds the complete prompt, negative prompt, seed, steps, sampler, CFG scale, model name and model hash directly into the PNG file as tEXt / iTXt chunks (the "PNG Info" / "Parameters" tab). Anyone who drags your image back into PNG Info can recreate it pixel-for-pixel.

That is a problem if you sell prompts, post client work, enter contests with "original art" rules, or simply do not want strangers reading fetish, medical, or NSFW prompts you experimented with. Prompt theft on Civitai, Reddit and Discord routinely starts with someone reading PNG chunks.

  • What gets embedded: positive + negative prompt, seed, steps, sampler (e.g. DPM++ 2M Karras), CFG, size, denoising strength, model hash, VAE, LoRA names, generation date.
  • Where it lives: PNG tEXt: parameters and workflow / prompt chunks (ComfyUI saves the full node graph as JSON).
  • Who can read it: anyone — drag into SD WebUI PNG Info, open in ExifTool (exiftool image.png), or use a free online PNG-text viewer.
  • What survives re-saving: screenshots and recompression usually drop it, but resize-in-place, rename, or upload to Discord/Google Drive preserves it.
ComfyUI warning

ComfyUI embeds far more than A1111 — the entire workflow JSON including custom node names, file paths, and sometimes your Windows username in model paths. Always strip ComfyUI PNGs before sharing outside trusted circles. See also our guides on removing C2PA credentials and Midjourney metadata.

How to check: run exiftool -Parameters image.png, or drop the file in the tool below — the instant preview lists the embedded parameters Vantawebs is about to delete.

How Vantawebs strips it: structural chunk removal. Vantawebs parses PNG chunks and deletes all tEXt, iTXt and zTXt ancillary chunks while leaving IDAT image data untouched — 100% lossless, same pixels, same resolution. No re-encode, no quality loss, no watermark.

Clean it now: drop your SD images in the tool below. Single files show an instant preview of the prompt data found; whole folders process in batch mode with one ZIP download.

Related: how to check if an image is AI-generated · what EXIF data is stored in photos.

Pro tip — strip before you upscale or post: clean the raw PNG the moment it leaves WebUI, then do hires-fix, upscaling or Photoshop passes on the clean copy. Upscalers and editors often inject their own software tags, so run one final pass before publishing. Keep one unstripped original in a private archive folder — if someone steals your style, the embedded seed and model hash are your proof of authorship.