Skip to content
checkaifree

Local tool

Stable Diffusion PNG info

Drop in an original PNG to read Stable Diffusion parameters or a ComfyUI workflow from the image. The file stays in your browser. The text you see is whatever was stored, and storing it is not the same as proving who made the picture.

17 October 2026 · Check AI Free

Automatic1111’s web UI documents a PNG Info feature that adds generation parameters to a PNG as a text chunk, so later software that can view PNG chunks can read them. ComfyUI’s workflow-metadata docs say a PNG from a built-in save node can carry two JSON fields, prompt and workflow, written as PNG text. Either field can be missing. A file saved with metadata disabled, or rewritten by another app, will not yield the graph. This page reads those chunks. It does not launch ComfyUI, and it does not decide that the image is authentic.

Local PNG text reader

Read saved prompts and workflow fields

Choose your original PNG to inspect tEXt, iTXt and zTXt fields, including text stored after image data. This reader stays in your browser and does not upload the file. It reads existing fields; it does not authenticate them or run a workflow.

Up to 10 MiB; 32 text fields; 256 KiB per field and 1 MiB total decoded text. Workflow JSON is bounded. Image pixels are not decoded by this reader. This page only reads PNG text. It does not run the image checker and does not upload the file.

ComfyUI/A1111 fields may be absent after export, screenshotting or editing. Text can include private prompts or paths: review it before sharing. Downloaded JSON is the stored field, not a verified or safe-to-execute workflow.

What the reader is doing

The same component runs on the Stable Diffusion page. Here it is the whole tool, aimed at the searches “stable diffusion png info” and “comfyui workflow from image.” It checks the PNG signature, chunk boundaries, CRC, and the text encodings used by tEXt, zTXt and iTXt. Latin-1 text, UTF-8 text and zlib-compressed text are in scope. Text stored after the image data is kept. Unknown chunks are skipped after their integrity check. Pixels are not decoded. The W3C PNG specification describes these text chunks; the reader follows that container, not a private Stable Diffusion format.

Limits, enforced before anything is rendered as HTML: 10 MiB per file, 4,096 chunks, 32 text fields, 256 KiB for a single field and 1 MiB of decoded text in total. JSON walks are capped at 10,000 values and a depth of 40, and a workflow nodes array at 1,000 entries. A browser without DecompressionStream gets an explicit message for compressed chunks. Text is shown as text. You can copy a field or download valid JSON unchanged. Review it before you share it. Prompts and workflows often contain private paths, names and unpublished wording.

Read a result without inventing the missing half

  1. Step 1

    Confirm you still have a PNG

    JPEG screenshots and files that were renamed from JPEG to PNG have no PNG text chunks. The reader will say so. If the picture passed through a messenger, read the metadata guide before you expect a workflow to have survived.

  2. Step 2

    Find the keyword, not just a long string

    ComfyUI documents prompt and workflow. Automatic1111’s wiki describes generation parameters stored as PNG text. Of three public Automatic1111-related PNGs checked against Pillow for this project, two carried a tEXt keyword parameters. The reader prints the keyword it found. It does not rename fields to match a tutorial.

  3. Step 3

    Treat a parameters block as a claim

    A checkpoint name, a seed and a prompt describe what the file says. They can be copied onto another image. They do not identify the person who clicked “generate,” and they do not survive every export. If the field is missing, it stays missing. One of the public reference PNGs used while checking this reader had a large compressed profile and no parameters field at all.

  4. Step 4

    Do not run the JSON because it parsed

    A ComfyUI workflow from an image can reference nodes you do not have. Parsing it here only means the text fit the reader’s limits and, when it is JSON, that it was bounded well enough to flag as JSON. Open it in ComfyUI only if you trust the source and you expect to review every node.

  5. Step 5

    Ask a different tool for a different question

    Want a general estimate of whether the pixels look generated? Use the image checker or the checker on the Stable Diffusion page. That path can send a smaller copy to a detection provider. This reader does not. Want a signed history? Use a Content Credentials validator. A workflow is not one.

What was checked, and what was not

Format tests cover truncated files, bad CRCs, bad UTF-8, unsupported compression, oversized text and literal markup that must stay text. Separately, three unchanged PNGs from Wikimedia Commons were read with Pillow 12.3.0 and with this reader. Field names, text and dimensions matched. Two are public-domain files associated with Automatic1111 in their Commons descriptions; the third is CC BY-SA 4.0 by Benlisquare and also described there as an Automatic1111-front-end image. Those are interoperability checks on historical public files. They are not a survey of current ComfyUI versions, and they are not a user study. Browser display of those three particular files was still outstanding when the check was written up. The official ComfyUI SDXL example was used as another outside reference and is not stored in this repository.

If the PNG info is empty, the picture can still be generated, photographic or both. Continue with how to tell if an image is AI-generated instead of treating silence as a result.

Sources

Related