Yes, PNG files can have metadata, and more than people expect. Besides color and size information, a PNG can carry EXIF data with GPS coordinates, the author's name, the software used, and for AI images, the full prompt. We tested six common ways of converting one: some removed everything, and one quietly kept the author and the prompt. Here's what's in a PNG, how to see it, and how to strip it.
They can. For years PNG had no official place for EXIF, so most PNGs simply didn't carry it, and that's where the idea that "PNGs have no metadata" comes from. Since 2017 the format has had an eXIf chunk that holds exactly the same EXIF data as a JPEG: device, date taken, GPS location. Plenty of software writes it.
And EXIF was never the only kind. A PNG is a series of labeled chunks, and several of them hold information beyond the pixels:
| Chunk | What it holds | Privacy risk |
|---|---|---|
| tEXt, zTXt, iTXt | Text notes: author, software, comments, AI prompts | High: can hold anything, including names and prompts |
| eXIf | Camera-style EXIF: device, date taken, GPS | High if GPS is present |
| iTXt "XML:com.adobe.xmp" | XMP: creator, editing history, rights | Medium |
| tIME | When the image was last modified | Low |
| iCCP, sRGB, gAMA | Color information | None |
| pHYs | Pixel density (e.g. 300 DPI) | None |
The text chunks are the ones to watch. They're free-form, so any app can write anything there, and you won't see it by opening the image.
Often, yes. Popular Stable Diffusion interfaces save the full prompt, seed, sampler and model name in a text chunk, usually called "parameters," and ComfyUI saves its whole workflow. If you've shared AI art as a PNG, anyone with a metadata viewer may be able to read the exact prompt you used. Other generators write nothing, or only a short label, and some platforms remove it on upload. Missing metadata doesn't prove an image is human-made; how to tell if an image is AI-generated covers better signals.
We built a test PNG with everything in it: an author name, a comment, an AI prompt, XMP, a color profile, and EXIF with GPS coordinates. Then we ran it through common tools and checked which chunks survived:
| Route | Text (author, comment, AI prompt) | EXIF and GPS | XMP | Color profile |
|---|---|---|---|---|
| Original test file | Kept | Kept | Kept | Kept |
| ImageMagick, PNG to PNG | Kept | Removed | Removed | Kept, plus new dates added |
| ImageMagick with -strip | Removed | Removed | Removed | Removed |
| ImageMagick, PNG to JPG | Comment only | Removed | Removed | Kept |
| Python Pillow, re-save as PNG | Removed | Removed | Removed | Kept |
| Browser canvas, save as PNG | Removed | Removed | Removed | Removed |
| Browser canvas, save as JPG (our metadata remover) | Removed | Removed | Removed | Generic sRGB only |
Two results stand out. ImageMagick (version 6.9.11) dropped the GPS but kept the author name and the AI prompt, and it added its own creation and modification dates, so a "converted" file can carry more about you than you think. Browser canvas exports, which is how our image tools work, kept nothing except a generic color profile on JPEGs. The test file was one we made ourselves, so treat this as a check of each tool's behavior rather than a survey of real-world PNGs.
Drop it into our EXIF viewer. On our test file it showed the author, the software, the comment, the full AI prompt, the device and the GPS position, all read in your browser without uploading the image. One limit: it didn't list the XMP fields, which needed a full parse. For a complete dump, ExifTool reads every chunk; there are lighter options in our ExifTool alternatives guide.
exiftool -all= image.png, or magick image.png -strip clean.png with ImageMagick. Don't rely on a plain ImageMagick conversion; it kept the text in our test.Screenshots deserve a mention, since most are PNGs. They don't usually carry GPS, but the image itself can give a lot away; see do screenshots have metadata.
Yes. Since 2017 PNG has supported an eXIf chunk that can hold the same EXIF data as a JPEG, including GPS coordinates. Many PNGs don't have one, but you should check before sharing rather than assume.
Not reliably. In our test, ImageMagick's PNG to PNG conversion removed the GPS but kept the author name and an AI prompt, while browser-based conversion removed everything. Check the converted file in a metadata viewer.
Many do. Stable Diffusion tools commonly store the prompt, seed and model in a PNG text chunk, and ComfyUI stores its workflow. Anyone with a metadata viewer can read it unless the file has been stripped or re-encoded.
Usually a little: image dimensions, a color profile and sometimes the software or device name. Screenshots rarely include GPS. The bigger privacy risk is what's visible in the image itself.
Use a tool that re-encodes as PNG rather than JPG, such as a browser-based image compressor saving as PNG, or run exiftool -all= on the file. Then check the result in a metadata viewer.