Pixels are not metadata
The rendered image is one layer. Its container organises chunks, segments or boxes around those pixels. Metadata describes capture, creation, rights, software or generation settings. A field is informative, but it is not automatically trustworthy unless a cryptographic system binds it to the file.
What generation settings can be stored?
Common fields include a positive prompt, negative prompt, seed, sampler, scheduler, steps, CFG scale, checkpoint or model hash, dimensions, denoise strength, LoRA and VAE names. A seed guides randomness; it does not reproduce the same image without the same model, software, workflow and deterministic operations.
PNG text chunks
PNG is a sequence of typed chunks. Applications can store text in tEXt, compressed zTXt or international iTXt chunks. ExifTool documents these locations. Keys are application conventions rather than universal AI fields.
Source: ExifTool PNG Tags
ComfyUI workflow and prompt JSON
ComfyUI PNG files can carry a full editable workflow and a separate prompt graph. The project documents that generated images can be loaded back into the interface to restore a workflow. Current writers use keys such as prompt and additional PNG information. A workflow graph and an API prompt graph are related, but not identical representations.
AUTOMATIC1111 parameters
AUTOMATIC1111 commonly writes a human-readable parameters block into PNG text. Its PNG Info interface can read the saved prompt and settings. Export options, conversion and metadata stripping determine whether those fields survive.
EXIF, XMP and IPTC
EXIF covers imaging and capture fields such as dimensions, timestamps, software and camera settings. XMP is an extensible XML/RDF data model defined by ISO 16684-1 and used by creative tools. The IPTC Photo Metadata Standard defines descriptive, rights and editorial fields. These values are usually editable.
Sources: Adobe XMP specifications · IPTC Photo Metadata Standard
JPEG, WebP and ISO BMFF
JPEG and WebP typically place EXIF or XMP in format-specific segments or chunks rather than PNG text. AVIF, HEIC, MP4 and MOV use ISO Base Media File Format boxes. Conversion between formats may rewrite or discard metadata even when the visible image looks unchanged.
Audio and video containers
Audio and video have container-level tags and stream-level technical fields. A title or artist tag belongs to a different layer than codec, frame rate, dimensions or sample rate. ffprobe exposes format tags and stream data separately, which is why this site reports them separately.
Source: FFmpeg ffprobe documentation
C2PA is not ordinary metadata
A C2PA manifest can contain actions, ingredients, thumbnails and descriptive assertions, but a signature and content binding make later changes detectable. It may be embedded or externally referenced. The C2PA specification treats provenance as a validation problem, not a free-form text field.
Source: C2PA Technical Specification 2.4
Which editors and readers can open these records?
| Tool | Best used for | Scope |
|---|---|---|
| ComfyUI | Its embedded workflow and prompt graphs | ComfyUI conventions |
| AUTOMATIC1111 PNG Info | Saved prompt and generation parameters | AUTOMATIC1111-style blocks |
| ExifTool | Broad EXIF, XMP, IPTC and container tags | Metadata, not an AI verdict |
| Adobe Bridge / Photoshop | Common XMP and IPTC editing | Fields supported by the application |
| ffprobe | Audio/video formats, streams and tags | Technical container inspection |
| C2PA validator | Manifest, signature and asset-binding validation | Supported Content Credentials |
Why prompts and workflows disappear
A screenshot, messenger, social platform, “strip metadata” option, re-encode or editor export can remove these records. A generator can also be configured not to save them. Missing prompt or workflow data is not evidence that AI was not used.
Why this site reads supported structures dependably
- Identify the file container before interpreting fields.
- Inspect multiple standard and application-specific storage locations.
- Keep raw bounded entries separate from normalised prompt and parameter fields.
- Parse known ComfyUI and AUTOMATIC1111 conventions without inventing absent values.
- Validate C2PA separately from editable EXIF, XMP, IPTC and PNG text.
- Report unsupported or missing layers explicitly.
Frequently asked questions
Can a prompt always be recovered?
No. It must have been stored and preserved in a supported structure.
Does a seed reproduce the exact image?
Not by itself. The model, software, workflow and other settings also matter.
Can metadata prove AI generation?
An explicit workflow or generator field can be strong evidence for that file, but ordinary metadata is editable. Signed provenance has a different validation model.