What is stored in a PNG besides the image?
Internally, a PNG file is a series of chunks — small labelled blocks of data laid out one after another. Two chunks are essential: the IHDR header, which records the width, height, and colour type, and the IDAT chunks, which hold the compressed pixel data itself. Around those, a PNG can carry extra optional chunks, and that is where metadata lives. If you are new to the format, start with what is a PNG.
What metadata can a PNG contain?
The most common metadata chunks are textual: tEXt stores plain key-value pairs such as title, author, software, or copyright, zTXt stores the same thing compressed, and iTXt stores UTF-8 text that can also be compressed — useful for descriptions in any language. Beyond text, a tIME chunk records when the image was last modified, a pHYs chunk holds the physical pixel dimensions (which is how DPI is expressed), and the newer eXIf chunk can embed a full EXIF block like the ones found in photos.
Does a PNG contain location or EXIF data?
Usually not. Unlike JPG photos straight from a phone or camera, PNGs rarely include GPS coordinates or capture details, because PNG is most often used for graphics, screenshots, and exports rather than camera output. That said, the eXIf chunk makes it possible, and software, author, copyright, or colour-profile information can still be embedded — so a PNG is not automatically free of identifying data.
Why remove PNG metadata?
Two reasons: privacy and size. Embedded text can leak the software you used, your name, or a file path, so stripping it is common before publishing. Metadata also adds bytes, and removing it makes the file smaller. The good news is that many tools strip non-essential chunks while shrinking the image, so when you compress a PNG you often clean it at the same time. To understand what stays behind, see how PNG compression works.
Frequently asked questions
- Where is metadata stored inside a PNG?
- In separate chunks alongside the image data — text chunks (tEXt, zTXt, iTXt), a tIME chunk for the last-modified date, a pHYs chunk for DPI, and an eXIf chunk for EXIF data.
- Do PNG files contain GPS or location data?
- Rarely. Unlike JPG photos from phones, PNGs almost never carry GPS coordinates. They can still hold software, author, or copyright text, so it is worth checking before publishing.
- Does removing metadata change how the image looks?
- No. Stripping text, timestamp, or EXIF chunks leaves every pixel untouched. You only lose the embedded information, not image quality.
- Will compressing a PNG also remove its metadata?
- Often, yes. Many compressors discard non-essential chunks while shrinking the file, so you can clean and shrink an image in a single step.