Where PNG metadata lives
A PNG is a list of chunks. The image data sits in IDAT chunks; metadata sits in separate chunks:
| Chunk | What it holds |
|---|---|
| tEXt, zTXt, iTXt | Free-form text: Stable Diffusion “parameters”, ComfyUI “prompt” and “workflow” JSON, XMP |
| eXIf | EXIF data such as camera, time and GPS |
| caBX | C2PA Content Credentials |
| tIME, dSIG | Last-modified time and digital signatures |
See also: Remove Stable Diffusion prompts and ComfyUI workflows from PNG files
How to remove metadata from a PNG in three steps
- Drop your PNG files into the tool above — batches are fine.
- Open the report to see the prompt, workflow and other fields that were found.
- Click “Remove AI metadata” and download the cleaned files individually or as a ZIP.
See also: Batch remove metadata without uploading to a server
What is kept in the cleaned PNG
Only metadata chunks are removed. Everything that affects how the image looks stays: header, palette, image data, transparency (tRNS), gamma and chromaticity, the sRGB or ICC color profile, and APNG animation chunks. If the file declared an orientation, it is written back in a minimal eXIf chunk with a valid checksum.
Why not just re-save the PNG?
PNG compression is lossless, but re-saving still changes things. Redrawing a PNG through a browser canvas — what many online tools do — can drop the color profile, alter transparent edges and reduce 16-bit images to 8 bits. Cutting chunks avoids all of that: the IDAT data is exactly what your generator or editor wrote.
Prevent PNG metadata next time
If you never want generation data in your files, check your generator’s settings: ComfyUI can be started with --disable-metadata, and many Stable Diffusion interfaces have an option to stop saving generation parameters. For files you already have, cleaning them here is the fastest fix.
See also: What Metadata Do AI Image Generators Add? DALL·E, Firefly, Midjourney, Gemini and Stable Diffusion
Questions about cleaning PNG files
Will the PNG lose quality?
No. The image data chunks are copied byte for byte, so the picture is pixel-identical to the original.
Can someone recover my ComfyUI workflow after cleaning?
Not from the cleaned file — the prompt and workflow chunks are removed completely. Copies you shared earlier still contain them.
Is transparency preserved?
Yes. Alpha channels and the tRNS chunk are kept exactly as they were.
Are animated PNGs supported?
Yes. APNG animation chunks are kept, so the animation plays exactly as before.
Does the PNG file get smaller?
Usually, yes — especially for ComfyUI images, where the embedded workflow can add tens of kilobytes.
Are my PNGs uploaded?
No. Everything is processed in your browser and never leaves your device.