If you ship anything that touches AI-generated images — a thumbnail pipeline, a user-upload feature, a design tool — you've probably noticed something: the images your model spits out are heavier than they should be, and they carry baggage you never asked for.
That baggage is provenance metadata. Modern generators (GPT Image / DALL·E, Google's Nano Banana / Gemini, Midjourney, many hosted Stable Diffusion endpoints) stamp each output with tags that mark it as machine-made. Some of it is harmless. Some of it survives a Photoshop round-trip. And most developers have no idea it's even there until a downstream platform flags an image or a QA person asks "why does this PNG have a certificate chain in it?"
This is a hands-on guide to seeing that metadata and removing it — from the CLI, from Node, from Python, and (when you just want it gone) from the browser.
What actually gets embedded
There are four layers worth knowing about, because they don't all come off the same way:
