Detecting and Stripping AI Metadata (C2PA, EXIF, XMP) from Generated Images — A Developer's Guide

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: EXIF fields — the classic camera-metadata block. Generators repurpose fields like Software , ImageDescription , or a custom Make / Model to identify themselves. Trivial to read, trivial to strip. XMP packets — an XML blob (Adobe's format) holding richer provenance: model name, generation timestamp, sometimes a prompt hash. Lives in its own segment of the file. C2PA manifests — the interesting one. The Coalition for Content Provenance and Authenticity standard embeds a cryptographically signed manifest (stored in a JUMBF box) that records the asset's origin. Because it's signed, it's designed to be tamper-evident — which also means naive metadata strippers often miss it. Pixel-level watermarks — e.g. SynthID-style signals baked into the pixels themselves. These are not metadata at all; no EXIF tool touches them. (More on the limits below.) The mistake I see repeatedly: someone runs a one-liner that clears EXIF, sees "no EXIF" in their viewer, and assumes the image is clean. The C2PA manifest and XMP pac